Survival prediction in patients with chronic limb-threatening ischemia who undergo infrainguinal revascularization

Competing risk analysis to estimate amputation incidence and risk in lower-extremity peripheral artery disease

Background: Patients with peripheral artery disease face high amputation and mortality risk. When assessing vascular outcomes, consideration of mortality as a competing risk is not routine. We hypothesize standard time-to-event methods will overestimate major amputation risk in chronic limb-threatening ischemia (CLTI) and non-CLTI. Methods: Patients undergoing peripheral vascular intervention from 2017 to 2018 were abstracted from the Vascular Quality Initiative registry and stratified by mean age (⩾ 75 vs < 75 years). Mortality and amputation data were obtained from Medicare claims. The 2-year cumulative incidence function (CIF) and risk of major amputation from standard time-to-event analysis (1 - Kaplan-Meier and Cox regression) were compared with competing risk analysis (Aalen-Johansen and Fine-Gray model) in CLTI and non-CLTI. Results: A total of 7273 patients with CLTI and 5095 with non-CLTI were included. At 2-year follow up, 13.1% of patients underwent major amputation and 33.4% died without major amputation in the CLTI cohort; 1.3% and 10.7%, respectively, in the non-CLTI cohort. In CLTI, standard time-to-event analysis overestimated the 2-year CIF of major amputation by 20.5% and 13.7%, respectively, in patients ⩾ 75 and < 75 years old compared with competing risk analysis. The standard Cox regression overestimated adjusted 2-year major amputation risk in patients ⩾ 75 versus < 75 years old by 7.0%. In non-CLTI, the CIF was overestimated by 7.1% in patients ⩾ 75 years, and the adjusted risk was overestimated by 5.1% compared with competing risk analysis. Conclusions: Standard time-to-event analysis overestimates the incidence and risk of major amputation, especially in CLTI. Competing risk analyses are alternative approaches to estimate accurately amputation risk in vascular outcomes research.

Comparison of mortality and amputation after lower extremity bypass versus peripheral vascular intervention in patients with chronic limb-threatening ischemia and comorbid chronic kidney disease

OBJECTIVE

Comorbid chronic kidney disease (CKD) is associated with worse outcomes for patients with chronic limb-threatening ischemia (CLTI). However, comparative effectiveness data are limited for lower extremity bypass (LEB) vs peripheral vascular intervention (PVI) in patients with CLTI and CKD. We aimed to evaluate (1) 30-day all-cause mortality and amputation and (2) 5-year all-cause mortality and amputation for LEB vs PVI in patients with comorbid CKD.

METHODS

Individuals who underwent LEB and PVI were queried from the Vascular Quality Initiative with Medicare claims-linked outcomes data. Propensity scores were calculated using 13 variables, and a 1:1 matching method was used. The mortality risk at 30 days and 5 years in LEB vs PVI by CKD was assessed using Kaplan-Meier and Cox proportional hazards models, with interaction terms added for CKD. For amputation, cumulative incidence functions and Fine-Gray models were used to account for the competing risk of death, with interaction terms for CKD added.

RESULTS

Of 4084 patients (2042 per group), the mean age was 71.0 ± 10.8 years, and 69.0% were male. Irrespective of CKD status, 30-day mortality (hazard ratio [HR]: 0.94, 95% confidence interval [CI]: 0.63-1.42, P = .78) was similar for LEB vs PVI, but LEB was associated with a lower risk of 30-day amputation (sub-HR [sHR]: 0.66, 95% CI: 0.44-0.97, P = .04). CKD status, however, did not modify these results. Similarly, LEB vs PVI was associated with a lower risk of 5-year mortality (HR: 0.79, 95% CI: 0.71-0.88, P < .001) but no difference in 5-year amputation (sHR: 1.03, 95% CI: 0.89-1.20, P = .67). CKD status did not modify these results.

CONCLUSIONS

Regardless of CKD status, patients had a lower risk of 5-year all-cause mortality and 30-day amputation with LEB vs PVI. Results may help inform preference-sensitive treatment decisions on LEB vs PVI for patients with CLTI and CKD, who may commonly be deemed too high risk for surgery.

Infra-inguinal bypass surgery vs endovascular revascularization for chronic limb-threatening ischemia in average- and high-risk patients

OBJECTIVE

This study aimed to evaluate treatment outcomes after bypass surgery or endovascular therapy (EVT) in average- and high-risk patients with chronic limb-threatening ischemia (CLTI).

METHODS

We retrospectively analyzed multicenter data of patients who underwent infra-inguinal revascularization for CLTI between 2015 and 2022. A high-risk patient was defined as one with estimated 30-day mortality rate ≥5% or 2-year survival rate ≤50%, as determined by the Surgical Reconstruction vs Peripheral Intervention in Patients With Critical Limb Ischemia (SPINACH) calculator. The amputation-free survival (AFS), limb salvage (LS), wound healing, and 30-day mortality were compared separately for the average- and high-risk patients between the bypass and EVT with propensity score matching.

RESULTS

We analyzed 239 and 31 propensity score-matched pairs in the average- and high-risk patients with CLTI. In the average-risk patients, the 2-year AFS and LS rates were 78.1% and 94.4% in the bypass group and 63.0% and 87.7% in the EVT group (P < .001 and P = .007), respectively. The 1-year wound healing rates were 88.6% in the bypass group and 76.8% in the EVT group, respectively (P < .001). The 30-day mortality was 0.8% in the bypass surgery and 0.8% in the EVT group (P = .996). In the high-risk patients, there was no differences in the AFS, LS, and wound healing between the groups (P = .591, P = .148, and P = .074). The 30-day mortality was 3.2% in the bypass group and 3.2% in the EVT group (P = .991).

CONCLUSIONS

Bypass surgery is superior to EVT with respect to the AFS, LS, and wound healing in the average-risk patients. EVT is a feasible first-line treatment strategy for high-risk patients with CLTI undergoing revascularization, based on the lack of significant differences in the 2-year AFS rate, between the bypass surgery and EVT cohorts.

Relevance of BEST-CLI trial endpoints in a tertiary care limb preservation program

OBJECTIVE

Major adverse limb event-free survival (MALE-FS) differed significantly by initial revascularization approach in the BEST-CLI randomized trial. The BEST-CLI trial represented a highly selected subgroup of patients seen in clinical practice; thus, we examined the endpoint of MALE-FS in an all-comers tertiary care practice setting.

METHODS

This is a single-center retrospective study of consecutive, unique patients who underwent technically successful infrainguinal revascularization for chronic limb-threatening ischemia (2011-2021). MALE was major amputation (transtibial or above) or major reintervention (new bypass, open bypass revision, thrombectomy, or thrombolysis).

RESULTS

Among 469 subjects, the mean age was 70 years, and 34% were female. Characteristics included diabetes (68%), end-stage renal disease (ESRD) (16%), Wound, Ischemia, and foot Infection (WIfI) stage 4 (44%), Global Limb Anatomic Staging System (GLASS) stage 3 (62%), and high pedal artery calcium score (pMAC) (22%). Index revascularization was autogenous vein bypass (AVB) (30%), non-autogenous bypass (NAB) (13%), or endovascular (ENDO) (57%). The composite endpoint of MALE or death occurred in 237 patients (51%) at a median time of 189 days from index revascularization. In an adjusted Cox model, factors independently associated with MALE or death included younger age, ESRD, WIfI stage 4, higher GLASS stage, and moderate-severe pMAC, whereas AVB was associated with improved MALE-FS. Freedom from MALE-FS, MALE, and major amputation at 30 days were 90%, 92%, and 95%; and at 1 year were 63%, 70%, and 83%, respectively. MALE occurred in 144 patients (31%) and was associated with ESRD, WIfI stage, GLASS stage, pMAC score, and index revascularization approach. AVB had superior durability, with adjusted 2-year freedom from MALE of 72%, compared with 66% for ENDO and 51% for NAB. Within the AVB group, spliced vein conduit had higher MALE compared with single-segment vein (hazard ratio, 1.8; 95% confidence interval, 0.9-3.7; P = .008 after inverse propensity weighting), but there was no statistically significant difference in major amputation. Of the 144 patients with any MALE, the first MALE was major reintervention in 47% and major amputation in 53%. Major amputation as first MALE was associated with non-AVB index approach. Indications for major reintervention were symptomatic stenosis/occlusion (54%), lack of clinical improvement (28%), asymptomatic graft stenosis (16%), and iatrogenic events (3%). Conversion to bypass occurred after 6% of ENDO cases, two-thirds of which involved distal bypass targets at the ankle or foot.

CONCLUSIONS

In this consecutive, all-comers cohort, disease complexity was associated with procedural selection and MALE-FS. AVB independently provided the greatest MALE-FS and freedom from MALE and major amputation. Compared with the BEST-CLI randomized trial, MALE after ENDO in this series was more frequently major amputation, with relatively few conversions to open bypass.

Long-Term Mortality Predictors Using a Machine-Learning Approach in Patients With Chronic Limb-Threatening Ischemia After Peripheral Vascular Intervention

BACKGROUND

Patients with chronic limb-threatening ischemia (CLTI) face a high long-term mortality risk. Identifying novel mortality predictors and risk profiles would enable individual health care plan design and improved survival. We aimed to leverage a random survival forest machine-learning algorithm to identify long-term all-cause mortality predictors in patients with CLTI undergoing peripheral vascular intervention.

METHODS AND RESULTS

Patients with CLTI undergoing peripheral vascular intervention from 2017 to 2018 were derived from the Medicare-linked VQI (Vascular Quality Initiative) registry. We constructed a random survival forest to rank 66 preprocedural variables according to their relative importance and mean minimal depth for 3-year all-cause mortality. A random survival forest of 2000 trees was built using a training sample (80% of the cohort). Accuracy was assessed in a testing sample (20%) using continuous ranked probability score, Harrell C-index, and out-of-bag error rate. A total of 10 114 patients were included (mean±SD age, 72.0±11.0 years; 59% men). The 3-year mortality rate was 39.1%, with a median survival of 1.4 years (interquartile range, 0.7-2.0 years). The most predictive variables were chronic kidney disease, age, congestive heart failure, dementia, arrhythmias, requiring assisted care, living at home, and body mass index. A total of 41 variables spanning all domains of the biopsychosocial model were ranked as mortality predictors. The accuracy of the model was excellent (continuous ranked probability score, 0.172; Harrell C-index, 0.70; out-of-bag error rate, 29.7%).

CONCLUSIONS

Our random survival forest accurately predicts long-term CLTI mortality, which is driven by demographic, functional, behavioral, and medical comorbidities. Broadening frameworks of risk and refining health care plans to include multidimensional risk factors could improve individualized care for CLTI.

Prognostic value of left ventricular systolic function before vascular surgery: a systematic review

BACKGROUND

Vascular surgery carries a high risk of post-operative cardiac complications. Recent studies have shown an association between asymptomatic left ventricular systolic dysfunction and increased risk of major adverse cardiovascular events (MACE). This systematic review aims to evaluate the prognostic value of left ventricular function as determined by left ventricular ejection fraction (LVEF) measured by resting echocardiography before vascular surgery.

METHODS

This review conformed to PRISMA and MOOSE guidelines. PubMed, OVID Medline and Cochrane databases were searched from inception to 27 October 2022. Eligible studies assessed vascular surgery patients, with multivariable-adjusted or propensity-matched observational studies measuring LVEF via resting echocardiography and providing risk estimates for outcomes. The primary outcomes measures were all-cause mortality and congestive heart failure at 30 days. Secondary outcome included the composite outcome MACE.

RESULTS

Ten observational studies were included (4872 vascular surgery patients). Studies varied widely in degree of left ventricular systolic dysfunction, symptom status, and outcome reporting, precluding reliable meta-analysis. Available data demonstrated a trend towards increased incidence of all-cause mortality, congestive heart failure and MACE in patients with pre-operative LVEF <50%. Methodological quality of the included studies was found to be of moderate quality according to the Newcastle Ottawa Checklist.

CONCLUSION

The evidence surrounding the prognostic value of LVEF measurement before vascular surgery is currently weak and inconclusive. Larger scale, prospective studies are required to further refine cardiac risk prediction before vascular surgery.

Validation of JCLIMB, SPINACH, and VQI Calculators for Prediction of Two Year Survival in Patients With Chronic Limb Threatening Ischaemia After Infra-Inguinal Surgical or Endovascular Revascularisation

OBJECTIVE

This study aimed to evaluate three survival prediction models: the JAPAN Critical Limb Ischaemia Database (JCLIMB), Surgical Reconstruction Versus Peripheral Intervention in Patients With Critical Limb Ischaemia (SPINACH), and Vascular Quality Initiative (VQI) calculators.

METHODS

Multicentre data of patients who underwent infrainguinal revascularisation for chronic limb threatening ischaemia between 2018 and 2021 were analysed retrospectively. The prediction models were validated using a calibration plot analysis with the intercept and slope. The discrimination was evaluated using area under the curve (AUC) analysis. The observed two year overall survival (OS) was evaluated by the Kaplan - Meier method. The two year OS predicted by each model at < 50%, 50 - 70%, and > 70% was defined as high, medium, and low risk, respectively.

RESULTS

A total of 491 patients who underwent infra-inguinal revascularisation were analysed. The rates of surgical revascularisation, endovascular therapy, and hybrid therapy were 26.5%, 70.1%, and 5.5%, respectively. The average age was 75.6 years, and the percentages of patients with diabetes mellitus and dialysis dependent end stage renal disease were 66.6% and 44.6%, respectively. The tissue loss rate was 85.7%. The intercept and slope were -0.13 and 1.18 for the JCLIMB, 0.11 and 0.82 for the SPINACH, and -0.15 and 1.10 for the VQI. The AUC for the two year OS of JCLIMB, SPINACH, and VQI were 0.758, 0.756, and 0.740, respectively. The observed two year OS rates of low, medium, and high risk using the JCLIMB calculator were 80.1%, 61.1%, and 28.5%, respectively (p < .001), using the SPINACH calculator were 81.0%, 57.0%, and 38.1%, respectively (p < .001), and using the VQI calculator were 77.8%, 45.8%, and 49.6%, respectively (p < .001).

CONCLUSION

The JCLIMB, SPINACH, and VQI survival calculation models were useful, although the OS predicted by the VQI model appeared to be lower than the observed OS.

Using Machine Learning (XGBoost) to Predict Outcomes After Infrainguinal Bypass for Peripheral Artery Disease

OBJECTIVE

To develop machine learning (ML) algorithms that predict outcomes after infrainguinal bypass.

BACKGROUND

Infrainguinal bypass for peripheral artery disease carries significant surgical risks; however, outcome prediction tools remain limited.

METHODS

The Vascular Quality Initiative database was used to identify patients who underwent infrainguinal bypass for peripheral artery disease between 2003 and 2023. We identified 97 potential predictor variables from the index hospitalization [68 preoperative (demographic/clinical), 13 intraoperative (procedural), and 16 postoperative (in-hospital course/complications)]. The primary outcome was 1-year major adverse limb event (composite of surgical revision, thrombectomy/thrombolysis, or major amputation) or death. Our data were split into training (70%) and test (30%) sets. Using 10-fold cross-validation, we trained 6 ML models using preoperative features. The primary model evaluation metric was the area under the receiver operating characteristic curve (AUROC). The top-performing algorithm was further trained using intraoperative and postoperative features. Model robustness was evaluated using calibration plots and Brier scores.

RESULTS

Overall, 59,784 patients underwent infrainguinal bypass, and 15,942 (26.7%) developed 1-year major adverse limb event/death. The best preoperative prediction model was XGBoost, achieving an AUROC (95% CI) of 0.94 (0.93-0.95). In comparison, logistic regression had an AUROC (95% CI) of 0.61 (0.59-0.63). Our XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs (95% CI's) of 0.94 (0.93-0.95) and 0.96 (0.95-0.97), respectively. Calibration plots showed good agreement between predicted and observed event probabilities with Brier scores of 0.08 (preoperative), 0.07 (intraoperative), and 0.05 (postoperative).

CONCLUSIONS

ML models can accurately predict outcomes after infrainguinal bypass, outperforming logistic regression.

Evaluation of short-term mortality in patients with Medicare undergoing endovascular interventions for chronic limb-threatening ischemia

INTRODUCTION

Patients with chronic limb-threatening ischemia (CLTI) have high mortality rates after revascularization. Risk stratification for short-term outcomes is challenging. We aimed to develop machine-learning models to rank predictive variables for 30-day and 90-day all-cause mortality after peripheral vascular intervention (PVI).

METHODS

Patients undergoing PVI for CLTI in the Medicare-linked Vascular Quality Initiative were included. Sixty-six preprocedural variables were included. Random survival forest (RSF) models were constructed for 30-day and 90-day all-cause mortality in the training sample and evaluated in the testing sample. Predictive variables were ranked based on the frequency that they caused branch splitting nearest the root node by importance-weighted relative importance plots. Model performance was assessed by the Brier score, continuous ranked probability score, out-of-bag error rate, and Harrell's C-index.

RESULTS

A total of 10,114 patients were included. The crude mortality rate was 4.4% at 30 days and 10.6% at 90 days. RSF models commonly identified stage 5 chronic kidney disease (CKD), dementia, congestive heart failure (CHF), age, urgent procedures, and need for assisted care as the most predictive variables. For both models, eight of the top 10 variables were either medical comorbidities or functional status variables. Models showed good discrimination (C-statistic 0.72 and 0.73) and calibration (Brier score 0.03 and 0.10).

CONCLUSION

RSF models for 30-day and 90-day all-cause mortality commonly identified CKD, dementia, CHF, need for assisted care at home, urgent procedures, and age as the most predictive variables as critical factors in CLTI. Results may help guide individualized risk-benefit treatment conversations regarding PVI.

Machine Learning to Predict Outcomes of Endovascular Intervention for Patients With PAD

Importance

Endovascular intervention for peripheral artery disease (PAD) carries nonnegligible perioperative risks; however, outcome prediction tools are limited.

Objective

To develop machine learning (ML) algorithms that can predict outcomes following endovascular intervention for PAD.

Design, Setting, and Participants

This prognostic study included patients who underwent endovascular intervention for PAD between January 1, 2004, and July 5, 2023, with 1 year of follow-up. Data were obtained from the Vascular Quality Initiative (VQI), a multicenter registry containing data from vascular surgeons and interventionalists at more than 1000 academic and community hospitals. From an initial cohort of 262 242 patients, 26 565 were excluded due to treatment for acute limb ischemia (n = 14 642) or aneurysmal disease (n = 3456), unreported symptom status (n = 4401) or procedure type (n = 2319), or concurrent bypass (n = 1747). Data were split into training (70%) and test (30%) sets.

Exposures

A total of 112 predictive features (75 preoperative [demographic and clinical], 24 intraoperative [procedural], and 13 postoperative [in-hospital course and complications]) from the index hospitalization were identified.

Main Outcomes and Measures

Using 10-fold cross-validation, 6 ML models were trained using preoperative features to predict 1-year major adverse limb event (MALE; composite of thrombectomy or thrombolysis, surgical reintervention, or major amputation) or death. The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). After selecting the best performing algorithm, additional models were built using intraoperative and postoperative data.

Results

Overall, 235 677 patients who underwent endovascular intervention for PAD were included (mean [SD] age, 68.4 [11.1] years; 94 979 [40.3%] female) and 71 683 (30.4%) developed 1-year MALE or death. The best preoperative prediction model was extreme gradient boosting (XGBoost), achieving the following performance metrics: AUROC, 0.94 (95% CI, 0.93-0.95); accuracy, 0.86 (95% CI, 0.85-0.87); sensitivity, 0.87; specificity, 0.85; positive predictive value, 0.85; and negative predictive value, 0.87. In comparison, logistic regression had an AUROC of 0.67 (95% CI, 0.65-0.69). The XGBoost model maintained excellent performance at the intraoperative and postoperative stages, with AUROCs of 0.94 (95% CI, 0.93-0.95) and 0.98 (95% CI, 0.97-0.99), respectively.

Conclusions and Relevance

In this prognostic study, ML models were developed that accurately predicted outcomes following endovascular intervention for PAD, which performed better than logistic regression. These algorithms have potential for important utility in guiding perioperative risk-mitigation strategies to prevent adverse outcomes following endovascular intervention for PAD.

Peak Aortic Valve Jet Velocity is an Independent Predictor of Mortality of Dialysis Patients Undergoing Open Surgery for Chronic Limb Threatening Ischemia

BACKGROUND

To investigate the impact of peak aortic jet velocity (Vmax) on the prognosis of patients undergoing open surgery for chronic limb threatening ischemia (CLTI).

METHODS

Between April 2015 and March 2022, 352 patients underwent infrainguinal open surgery for CLTI. Patients who met the following exclusion criteria were excluded: subsequent infrainguinal surgeries in the registered period, no record of Vmax, history of aortic valve intervention, and Vmax ≥3.0 m/s (moderate or severe aortic valve stenosis). The remaining patients were dichotomized into 2 groups based on their Vmax values. The Youden index calculated from the receiver operating characteristic curve (ROC) was set as the cutoff value. The 2-year overall survival (OS), calculated using the Kaplan-Meier's method, was compared between the 2 groups. A Cox proportional hazards regression analysis was performed using perioperative factors including Vmax to identify independent predictors separately for dialysis and nondialysis patients and the quantitative relationship between Vmax and OS.

RESULTS

One hundred and ninety-one patients, including 100 dialysis and 91 nondialysis patients, were included in the analysis. The Youden index was 1.7 m/s. The 2-year OS rates of the group with Vmax >1.7 m/s and with Vmax ≤1.7 m/s were 49% and 76% (P = 0.007), respectively, in the dialysis cohort, while they were 71% and 78% (P = 0.680) in the nondialysis cohort, respectively. Multivariate analysis identified Vmax and ejection fraction as independent predictors in the dialysis cohort and the Barthel Index at admission in the nondialysis cohort. There was a stepwise increase in the risk of death in patients with Vmax of ≥1.5 m/s and a significantly higher risk of death in dialysis patients with Vmax >2.5 m/s.

CONCLUSIONS

Vmax was a significant independent predictor of all-cause death within 2 years after open surgery for CLTI in dialysis patients but not in patients managed without dialysis.

Evaluation of endovascular treatment of chronic limb-threatening ischemia for patients in the PLAN gray zone

OBJECTIVE

To compare the results of endovascular therapy for chronic limb-threatening ischemia (CLTI) in patients categorized under the gray and yellow zones of the patient risk, limb severity, and anatomic pattern (PLAN) concept over a 2-year follow-up period.

METHODS

Patients who underwent endovascular therapy for peripheral artery disease and presented with CLTI from February 2017 to February 2019 were retrospectively reviewed. The patients were grouped into yellow and gray zones based on the PLAN concept. Preoperative and postoperative walking distances, Rutherford classes, and postoperative target vessel patency rates were recorded and compared between the groups. Follow-up evaluations were performed at 1, 6, 12, and 24 months post-procedure.

RESULTS

Of the 387 patients evaluated, the yellow and gray groups comprised 88 patients each. The overall patency rates were similar between the groups (84 (95.45%) vs. 81 (92.05%), respectively). The occlusion-/stenosis-free survival times, amputation-free survival time, and mean survival time were not significantly different. However, the gray group had a significantly higher number of atherectomy interventions (74 vs. 59) and crosser devices used (62 vs. 42).

CONCLUSION

Endovascular therapy is an effective treatment option for patients in the gray zone of the PLAN color coding system.

Dynamic Perfusion Computed Tomography for the Assessment of Concomitant Coronary Artery Disease in Patients with a History of Percutaneous Transluminal Angioplasty for Chronic Limb-Threatening Ischemia-A Pilot Study

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is associated with high rates of long-term cardiovascular mortality. Exercise stress testing to detect obstructive coronary artery disease (CAD) can be difficult in this subset of patients due to inability to undergo exercise testing, presence of balanced ischemia and severe coronary artery calcification (CAC).

AIM

To test the feasibility of regadenoson stress dynamic perfusion computed tomography (DPCT) in CLTI patients.

METHODS

Between 2018 and 2023, coronary computed tomography angiography (CTA) and, in the case of a calcium score higher than 400, DPCT, were performed in 25 CLTI patients with a history of endovascular revascularization.

RESULTS

Of the 25 patients, 19 had a calcium score higher than 400, requiring DPCT image acquisition. Obstructive CAD could be ruled out in 10 of the 25 patients. Of the 15 CTA/DPCT+ patients, 13 proceeded to coronary angiography (CAG). Revascularization was necessary in all 13 patients. In these 13 patients, vessel-based sensitivity and specificity of coronary CTA/DPCT as compared to invasive evaluation was 75%, respectively. At follow-up (27 ± 21 months) there was no statistically significant difference in all-cause mortality between CTA/DPCT- positive and -negative patients (p = 0.065).

CONCLUSIONS

Despite a high prevalence of severe CAC, coronary CTA complemented by DPCT may be a feasible method to detect obstructive and functionally significant CAD in CLTI patients.

Perioperative complications following open or endovascular revascularization for chronic limb-threatening ischemia in the BEST-CLI Trial

OBJECTIVE

Anticipated perioperative morbidity is an important factor for choosing a revascularization method for chronic limb-threatening ischemia (CLTI). Our goal was to assess systemic perioperative complications of patients treated with surgical and endovascular revascularization in the Best Endovascular vs Best Surgical Therapy in Patients with CLTI (BEST-CLI) trial.

METHODS

BEST-CLI was a prospective randomized trial comparing open (OPEN) and endovascular (ENDO) revascularization strategies for patients with CLTI. Two parallel cohorts were studied: Cohort 1 included patients with adequate single-segment great saphenous vein (SSGSV), whereas Cohort 2 included those without SSGSV. Data were queried for major adverse cardiovascular events (MACE-composite myocardial infarction, stroke, death), non-serious (non-SAEs) and serious adverse events (SAEs) (criteria-death/life-threatening/requiring hospitalization or prolongation of hospitalization/significant disability/incapacitation/affecting subject safety in trial) 30 days after the procedure. Per protocol analysis was used (intervention received without crossover), and risk-adjusted analysis was performed.

RESULTS

There were 1367 patients (662 OPEN, 705 ENDO) in Cohort 1 and 379 patients (188 OPEN, 191 ENDO) in Cohort 2. Thirty-day mortality in Cohort 1 was 1.5% (OPEN 1.8%; ENDO 1.3%) and in Cohort 2 was 1.3% (2.7% OPEN; 0% ENDO). MACE in Cohort 1 was 4.7% for OPEN vs 3.13% for ENDO (P = .14), and in Cohort 2, was 4.28% for OPEN and 1.05% for ENDO (P = .15). On risk-adjusted analysis, there was no difference in 30-day MACE for OPEN vs ENDO for Cohort 1 (hazard ratio [HR] 1.5; 95% confidence interval [CI], 0.85-2.64; P = .16) or Cohort 2 (HR, 2.17; 95% CI, 0.48-9.88; P = .31). The incidence of acute renal failure was similar across interventions; in Cohort 1 it was 3.6% for OPEN vs 2.1% for ENDO (HR, 1.6; 95% CI, 0.85-3.12; P = .14), and in Cohort 2, it was 4.2% OPEN vs 1.6% ENDO (HR, 2.86; 95% CI, 0.75-10.8; P = .12). The occurrence of venous thromboembolism was low overall and was similar between groups in Cohort 1 (OPEN 0.9%; ENDO 0.4%) and Cohort 2 (OPEN 0.5%; ENDO 0%). Rates of any non-SAEs in Cohort 1 were 23.4% in OPEN and 17.9% in ENDO (P = .013); in Cohort 2, they were 21.8% for OPEN and 19.9% for ENDO (P = .7). Rates for any SAEs in Cohort 1 were 35.3% for OPEN and 31.6% for ENDO (P = .15); in Cohort 2, they were 25.5% for OPEN and 23.6% for ENDO (P = .72). The most common types of non-SAEs and SAEs were infection, procedural complications, and cardiovascular events.

CONCLUSIONS

In BEST-CLI, patients with CLTI who were deemed suitable candidates for open lower extremity bypass surgery had similar peri-procedural complications following either OPEN or ENDO revascularization: In such patients, concern about risk of peri-procedure complications should not be a deterrent in deciding revascularization strategy. Rather, other factors, including effectiveness in restoring perfusion and patient preference, are more relevant.

Prognostic Value of Hospital Frailty Risk Score and Clinical Outcomes in Patients Undergoing Revascularization for Critical Limb-Threatening Ischemia

Background The impact of medical record-based frailty assessment on clinical outcomes in patients undergoing revascularization for critical limb-threatening ischemia (CLTI) is unknown. Methods and Results This study included patients with CLTI aged ≥18 years from the nationwide readmissions database 2016 to 2018 who underwent endovascular revascularization (ER) or surgical revascularization (SR). The hospital frailty risk score, a previously validated International Classification of Diseases, Tenth Edition, Clinical Modification (ICD-10-CM) claims-based score, was used to categorize patients into low- (<5), intermediate- (5-15), and high-risk (>15) frailty categories. Primary outcomes were in-hospital mortality and major amputation at 6 months. A total of 64 338 patients were identified who underwent ER (82.3%) or SR (17.7%) for CLTI. The mean (SD) age of the cohort was 69.3 (11.8) years, and 63% of patients were male. This study found a nonlinear association between hospital frailty risk score and in-hospital mortality and 6-month major amputation. In both ER and SR cohorts, the intermediate- and high-risk groups were associated with a significantly higher risk of in-hospital mortality (high-risk group: ER: odds ratio [OR], 7.2 [95% CI, 4.4-11.6], P<0.001; SR: OR, 28.6 [95% CI, 3.4-237.6], P=0.002) and major amputation at 6 months (high-risk group: ER: hazard ratio [HR], 1.6 [95% CI, 1.5-1.7], P<0.001; SR: HR, 1.7 [95% CI, 1.4-2.2], P<0.001) compared with the low-risk group. Conclusions The hospital frailty risk score, generated from the medical record, can identify frailty and predict in-hospital mortality and 6-month major amputation in patients undergoing ER or SR for CLTI. Further studies are needed to assess if this score can be incorporated into clinical decision-making in patients undergoing revascularization for CLTI.

Amputation-free survival in the long-term follow-up and gender-related characteristics in patients revascularized for critical limb ischemia

OBJECTIVE

Patients with Critical Limb Ischemia (CLI) present a high risk of cardiovascular events and death. Revascularization is the cornerstone of therapy to relieve ischemic pain and prevent limb loss. Literature data suggest that women tend to present with worse outcomes after revascularization. The aim of the present study is to determine amputation-free survival in a long-term follow-up in women and men following endovascular revascularization procedure for CLI.

METHODS

From November 2013 to December 2020, 357 consecutive patients were retrospectively included. Clinical and biological parameters were recorded at baseline before endovascular revascularization. During follow-up until February 2023, overall survival and amputation-free survival (freedom from major amputation) were analysed using the Kaplan-Meier method. Univariate and multivariate analyses were performed to study the parameters associated with amputation-free survival. A P<0.05 was considered as statistically significant.

RESULTS

A total of 357 consecutive patients were included, 189 men and 168 women with CLI, with a mean age of 78.6±12 years. Treated hypertension (79%), diabetes mellitus (48%), coronary artery disease (39%) and protein malnutrition (61%) were the most prevalent comorbidities. Women were older than men with a mean age of 82.4±11.4 years (versus 75.4±11 years in men) and presented more frequently with protein malnutrition (70% of women). Prevalence of diabetes, tobacco use and history of coronary heart disease were significantly higher in men. During the 10-year follow-up period, 241 patients had died (68%) and 38 (11%) underwent major amputation, of whom 22 patients were still alive on February 2023. Median survival was 35.5 months [IQR: 29.5; 43] in the overall population, 38.5 [32; 50.4] months in women and 33.5 months [24.7; 43.5] in men. No gender-related differences were noted according to peri-procedural complications, survival probability and amputation-free survival. In multivariate analysis for amputation-free survival, age, previous coronary heart disease, C-reactive protein level, left ventricular ejection fraction (LVEF)<60% and albumin level<35g/L were correlated with poor outcome. In particular, protein malnutrition, as a treatable risk factor, appears significantly correlated with poor outcome in both men and women (HR=2.50 [1.16;5.38], P=0.0196 in men; HR=1.77 [1.00;3.13], P=0.049 in women).

CONCLUSION

The present results highlight that mortality in patients after endovascular revascularization remains high with a mortality rate of 28% at 1 year, 40% at 2 years and 51% at 3 years. Women represented a distinct population, almost 10-year older than their male counterparts, with more prevalent protein malnutrition. However, no gender-related difference was noted according to amputation-free survival on the long-term follow-up. Associated risk factors are mainly age, a history of coronary heart disease, pre-procedural inflammatory syndrome and protein malnutrition. Correction of malnutrition could have the potential to improve functional and general long-term prognosis in patients with CLI together with optimal medical and interventional management.

Impact of ambulatory status change on survival in patients with chronic limb-threatening ischemia undergoing infrainguinal surgical or endovascular revascularization

OBJECTIVE

This study aimed to evaluate the influence of change in ambulatory status on the prognosis of patients with chronic limb-threatening ischemia (CLTI) undergoing infrainguinal bypass surgery or endovascular therapy (EVT).

METHODS

We retrospectively analyzed data from two vascular centers for patients who underwent revascularization for CLTI between 2015 and 2020. The primary endpoint was overall survival (OS), and the secondary endpoints were changes in ambulatory status and postoperative complications.

RESULTS

Throughout the study, 377 patients and 508 limbs were analyzed. In the preoperative nonambulation cohort, the average body mass index (BMI) was lower in the postoperative nonambulatory group than in the postoperative ambulatory group (P < .01). The percentage of cerebrovascular disease (CVD) was higher in the postoperative nonambulatory group than in the postoperative ambulatory group (P = .01). In the preoperative ambulation cohort, the average controlling nutritional status (CONUT) score was higher in the postoperative nonambulatory group than in the postoperative ambulatory group (P < .01). There was no difference in the bypass percentage and the EVT in the preoperative nonambulation (P = .32) and ambulation (P = .70) cohorts. According to the change in ambulatory status before and after revascularization, the 1-year OS rates were 86.8% in the ambulatory → ambulatory group, 81.1% in the nonambulatory → ambulatory group, 54.7% in the nonambulatory → nonambulatory group, and 23.9% in the ambulatory → nonambulatory group (P < .01). On multivariate analysis, increased age (P = .04), higher Wound, Ischemia, and foot Infection stage (P = .02), and increased CONUT score (P < .01) were independent risk factors for the decline in ambulatory status in patients with preoperative ambulation. In patients with preoperative nonambulation, increased BMI (P < .01) and absence of CVD (P = .04) were independent factors related to the improved ambulatory status. The percentages of postoperative complications were 31.0% and 17.0% in the preoperative nonambulation and the preoperative ambulation in the overall cohort (P < .01). Preoperative nonambulatory status (P < .01), CONUT score (P < .01), and bypass surgery (P < .01) were risk factors for postoperative complications.

CONCLUSIONS

Improved ambulatory status is associated with better OS in patients with preoperative nonambulatory status after infrainguinal revascularization for CLTI. Although patients with preoperative nonambulatory status have a risk of postoperative complication, some may benefit from revascularization if they have no factors such as low BMI and CVD, improving their ambulatory status.

Iliac artery calcification score stratifies mortality risk estimation in patients with chronic limb-threatening ischemia undergoing revascularization

OBJECTIVE

Patients with chronic limb-threatening ischemia (CLTI) are at high risk for adverse limb outcomes and mortality. Using the Vascular Quality Initiative (VQI) prediction model to estimate mortality after revascularization can assist with clinical decision-making. We aimed to improve the discrimination of the 2-year VQI risk calculator by incorporating a common iliac artery (CIA) calcification score based on computed tomography scans.

METHODS

This was a retrospective analysis of patients who underwent infrainguinal revascularization for CLTI from January 2011 to June 2020 and had a computed tomography scan of the abdomen/pelvis 2 years before or up to 6 months after revascularization. CIA calcium morphology, circumference, and length were scored. Bilateral scores were summed for the total calcium burden (CB) score, which was trichotomized (mild, 0-15; moderate, 16-19; severe, 20-22). The VQI CLTI model was used to categorize patients as low, medium, or high risk for mortality.

RESULTS

A total of 131 patients with a mean age of 69±12 years were included in the study, and 86 (66%) were men. CB scores were mild in 52 (40%), moderate in 26 (20%), and severe in 53 (40%) patients. Older patients (P = .0002) and those with coronary artery disease (P = .06) had higher CB scores. Patients with severe CB scores were more likely to undergo infrainguinal bypass compared with those with mild or moderate CB scores (P = .006). The 2-year VQI mortality risk was calculated to be low in 102 (78%), medium in 23 (18%), and high in 6 (4.6%) patients. In the "low-risk" VQI mortality subgroup, 46 (45%) patients had mild, 18 (18%) had moderate, and 38 (37%) had severe CB scores, and patients with severe CB scores had significantly higher risk of mortality compared with those with mild or moderate scores (hazard ratio, 2.5; 95% confidence interval, 1.2-5.1; P = .01). In this "low-risk" VQI mortality subgroup, CB score further stratified the risk of mortality (P = .04).

CONCLUSIONS

Higher total CIA calcification was significantly associated with mortality in patients undergoing infrainguinal revascularization for CLTI, and preoperative assessment of CIA calcification may help with perioperative risk stratification and guide clinical decision making in this population.

Case planning and execution of inframalleolar bypass for chronic limb-threatening ischemia

Chronic limb-threatening ischemia is challenging to treat because of the complex patient population, heterogeneity of limb presentations, and complicated arterial pathology. To meet this challenge, vascular surgeons need a broad range of skills to appropriately tailor interventions to each patient's specific needs. One tool in the armamentarium for patients with extensive arterial occlusive disease below the knee is an inframalleolar bypass. However, these procedures require a systematic approach to surgical planning and a high degree of technical competence. We describe our approach to inframalleolar bypass for limb preservation in suitable patients with advanced tibial artery disease.

To patch, or not to patch a common femoral artery, that is the question

OBJECTIVES

There is no strong evidence to support or reject the use of patch angioplasty (PA) after femoral endarterectomy (FE). The current study aimed to assess early postoperative complications and compare primary patency (PP) rates after FE in patients treated with PA versus direct closure (DC).

METHODS

This is a retrospective study of patients admitted during 06/2002-07/2017 with signs and symptoms of chronic lower limb ischemia (Rutherford categories 2-6). Patients with angiographically confirmed stenoses or occlusions of the common femoral arteries (CFAs) and managed with FE with or without PA were included in the study. Early postoperative wound complications were assessed. The PP analysis was based on imaging-confirmed data. The impact of PA on the patency was evaluated in a confounder-adjusted Cox regression model. PP rates were compared with log-rank between the PA and DC groups using Kaplan-Meier survival analysis in the propensity score-matched (PSM) cohorts.

RESULTS

A total of 295 primary FEs were identified. The patients' median age was 75 years. A total of 210 patients were managed with PA and 85 with DC. Altogether, 38 (12.9%) local wound complications were registered, 15 (5.1%) of which required re-interventions. There were 9 (3.2%) cases of deep wound infection, 20 (7.0%) seromas, and 11 (3.9%) cases of major bleeding, with no significant difference between the PA and DC groups. All of the infected patches were made of synthetic material, and 83% of them were removed. The PP analysis was performed on 50 PSM patient pairs with a median age of 74 years. The median imaging-confirmed follow-up lengths were 77 months (IQR = 47 months) for the PA patients and 27 months (IQR = 64 months) for the DC patients. The preoperative median diameter of the CFA was 8.8 mm (IQR = 3.4). The 5 year primary patency rates of CFAs with a minimum diameter of 5.5 mm managed with PA or DC exceeded 91%, p > 0.05. Female sex was associated with the loss of PP, odds ratio 4.17, p = 0.046.

CONCLUSIONS

Wound complications after FE with or without patching are not uncommon and often lead to reoperations. The PP rates of CFAs with a minimum diameter of 5.5 mm and accomplished with or without patching are comparable. Female sex is associated with the loss of patency.

Open revascularization approach is associated with healing and ambulation after transmetatarsal amputation in patients with chronic limb threatening ischemia

BACKGROUND

Transmetatarsal amputation (TMA) allows for maintenance of ambulatory function for patients with significant forefoot tissue loss. Effective revascularization is key to optimizing limb salvage for patients with chronic limb threatening ischemia (CLTI). We hypothesized that CLTI patients requiring TMA will have better healing and functional outcomes with open bypass than with endovascular revascularization.

METHODS

Consecutive TMAs performed at three affiliated centers between 2008 and 2020 were retrospectively reviewed. The baseline characteristics, including WIfI (wound, ischemia, foot infection) stage, noninvasive vascular studies, healing, and ambulatory outcomes, were collected. Catheter-based angiographic images were evaluated using the GLASS (global limb anatomic staging system). The primary outcomes were TMA healing and community ambulation. The secondary outcomes were TMA that had healed at study end, any ambulatory function postoperatively, major amputation, and mortality. Descriptive statistics and univariate, multivariable, and Kaplan-Meier analyses were performed.

RESULTS

A total of 346 TMAs had been performed in 318 patients, 209 of whom had had peripheral artery disease (PAD). The median follow-up was 2.5 years. Patients with PAD had had significantly lower rates of healing compared with those without PAD (64% vs 77%; P = .007). Revascularization was performed in 185 limbs, with 102 treated endovascularly and 83 with open surgery. The patients who had undergone endovascular surgery were significantly less likely to have had the TMA healed at any point (55% vs 76%; P = .003) and less likely to have remained healed at study end (49% vs 66%; P = .02). Patients with GLASS stage 3 anatomy were significantly more likely to have healed after open surgery (75% vs 45%; P = .003). Long-term ambulation data were available for 72% of the revascularized patients. Endovascular surgery was associated with a lower likelihood of community ambulation after TMA (34% vs 57%; P = .002). On multivariable analysis, open surgery was significantly associated with TMA healing (odds ratio, 2.8; P = .007) and ambulation (odds ratio, 2.9; P = .001).

CONCLUSIONS

For patients with CLTI and significant tissue loss requiring TMA, an initial open approach to revascularization was associated with improved healing and higher rates of ambulation compared with endovascular interventions. The metabolic requirement for healing of a TMA in patients with CLTI might be better met by open revascularization.

Presenting limb severity is associated with long-term outcomes after infrainguinal revascularization for chronic limb-threatening ischemia

OBJECTIVE

The SVS Wound, Ischemia, foot Infection (WIfI) limb staging system was established to estimate risk of major amputation in chronic limb-threatening ischemia (CLTI) and better stratify outcomes comparisons. There is little data on treatment outcomes beyond 1 year based on presenting WIfI stage.

METHODS

This is a single-institution retrospective study of 413 patients who underwent infrainguinal revascularization for CLTI (2011-2021) with data available for WIfI staging. Patient characteristics and outcomes were gathered from the electronic medical record. Data were analyzed based on presenting WIfI stage and initial treatment received at our center.

RESULTS

Presenting WIfI stages were 1 to 2 (23%), 3 (27%), and 4 (50%). Index revascularization approach was endoluminal (59%), autogenous vein bypass (29%), or non-autogenous bypass (13%). Operative mortality within 30 days was 2.9% and was not associated with WIfI stage or revascularization approach. Median limb follow-up time was 502 days (interquartile range [IQR], 112-1256 days), and median survival follow-up time was 932 days (IQR, 343-1770 days). Major amputation or death occurred in 19% and 46% of patients at median times of 119 days (IQR, 28-314 days) and 739 days (IQR, 204-1475 days), respectively. WIfI stage was independently associated with major amputation (P = .001), as was initial revascularization approach (P = .01). In a Cox proportional hazards model, factors independently associated with major amputation were male sex (hazard ratio [HR], 1.4; 95% confidence interval [CI], 1.04-2.0; P = .03), diabetes (HR, 1.8; 95% CI, 1.3-2.5; P = .001), WIfI stage 4 (HR, 2.3; 95% CI, 1.5-3.5; P < .001), and non-autogenous bypass (HR, 2.9; 95% CI, 2.1-4.2; P < .001). In a Cox proportional hazards model for mortality, independently associated factors were age (HR, 1.04; 95% CI, 1.02-1.05; P < .001), end-stage renal disease (HR, 2.8; 95% CI, 1.9-4.0; P < .001), congestive heart failure (HR, 1.9; 95% CI, 1.4-2.5; P < .001), chronic obstructive pulmonary disease (HR, 1.5; 95% CI, 1.1-2.1; P = .02), and WIfI stage 4 (HR, 1.6; 95% CI, 1.04-2.2; P = .03). Among those presenting with WIfI stage 4 limbs, Kaplan-Meier estimated rates of freedom from major amputation or death at 2 years were 71% ± 3.7% and 68% ± 3.5%, respectively. In an inverse propensity weighted Cox proportional hazards model, non-white race (HR, 1.5; 95% CI, 1.01-2.2; P = .047), diabetes (HR, 2.0; 95% CI, 1.2-3.3; P = .008), Global Anatomic Staging System infrapopliteal grade (HR, 1.2; 95% CI, 1.05-1.3; P = .005), non-autogenous bypass (HR, 3.2; 95% CI, 1.9-5.3; P < .001), and endoluminal revascularization (HR, 2.6; 95% CI, 1.6-4.3; P < .001) were independently associated with major amputation in the WIfI stage 4 subgroup.

CONCLUSIONS

Presenting WIfI stage is strongly associated with long-term risks of major amputation and death following infrainguinal revascularization for CLTI and should be used to stratify outcomes comparisons. Effective revascularization is critical in WIfI stage 4 disease, and autogenous vein bypass provides durable long-term limb preservation.

WIfI Classification Based Analysis of Risk Factors for Outcomes in Patients with Chronic Limb Threatening Ischaemia after Endovascular Revascularisation Therapy

OBJECTIVE

The evaluation of limb status with the Wound, Ischaemia, and foot Infection (WIfI) classification and the assessment of patient risks combined with systemic factors, are recommended in patients with chronic limb threatening ischaemia (CLTI). However, there is little evidence of the application of the WIfI classification in the Chinese population. This study aimed to verify the use of the WIfI classification in a Chinese patient population, and to further identify local and systemic independent predictors of adverse CLTI outcomes.

METHODS

A total of 474 patients who underwent endovascular therapy (EVT) for CLTI in a tertiary hospital between July 2017 and September 2020 were included in this retrospective study. The outcomes included one year major adverse limb events (MALEs), one year all cause mortality, and one year amputation free survival (AFS). Cox regression was used to analyse the association between risk factors and adverse outcomes.

RESULTS

In total, 104 (21.9%) all cause deaths were recorded. The rate of MALEs was 17.5%, while the AFS was 71.9%. Multivariable analysis revealed that a body mass index (BMI) < 18.5 kg/m2 (p = .002), a left ventricular ejection fraction (LVEF) < 50% (p < .001), and WIfI wound grade (p < .001) were independent risk factors for MALEs, while age ≥ 77 years (p = .031), BMI < 18.5 kg/m2 (p < .001), coronary heart disease (p = .040), and WIfI clinical stages (p = .021) were independent risk factors for death in patients with CLTI. Age ≥ 77 years (p = .003), BMI < 18.5 kg/m2 (p < .001), coronary heart disease (p = .012), LVEF < 50% (p < .001), WIfI wound grade (p = .004), and WIfI clinical stages (p = .044) were independently associated with a decreased AFS rate.

CONCLUSIONS

This study has confirmed the predictive ability of the WIfI classification for Chinese patients with CLTI who underwent EVT. Wound grade was the most sensitive and important risk factor of the three components of WIfI. In addition, systemic factors should be considered to ensure a more accurate prognosis prediction and appropriate clinical decision making in patients with CLTI.

Effectiveness of the Vascular Quality Initiative Chronic Limb-Threatening Ischemia Mortality Prediction Model in Patents with Distal Bypass

BACKGROUND

The purpose of this study is to evaluate the effectiveness of mortality prediction using the Vascular Quality Initiative (VQI) chronic limb-threatening ischemia (CLTI) model in patients with distal bypass.

METHODS

Patients who underwent distal bypass for CLTI from 2009 to 2020 at a single center were retrospectively reviewed. Distal bypass was defined as any bypass with a distal anastomosis to the posterior tibial, anterior tibial, dorsalis pedis, plantar, or peroneal artery. Baseline characteristics, operative details, hospital outcomes, and medium-term outcomes were compared among patients with a low-, medium-, and high-risk of mortality based on a VQI CLTI calculation. The primary endpoints were survival and limb salvage.

RESULTS

A total of 287 distal bypasses were performed in 230 patients (153 males; median age, 74 years; diabetes mellitus, 70%; end-stage renal disease [ESRD] with hemodialysis, 38%). These patients were stratified into 153 (66%) low-, 35 (15%) medium-, and 42 (18%) high-risk cases based on the VQI CLTI model. There were two hospital deaths (1%) within 30 days. During a mean follow-up period of 33 ± 29 months, 105 patients died and 26 limbs (9%) required major amputation. The 2-year survival rate of 81% in the low-risk group was significantly higher than those of 41% in the medium-risk group and 46% in the high-risk group (both P < 0.001). The 2-year survival rates did not differ significantly between the medium- and high-risk groups (P = 0.81). The 2-year limb salvage rate of 93% in the low-risk group was significantly higher than those of 81% in the medium-risk (P = 0.023) and those of 87% in the high-risk (P = 0.039) groups. There were no significant differences in graft patency and wound healing among the three groups.

CONCLUSIONS

These results suggest that distal bypass is optimal treatment for patients with a low VQI-predicted risk of mortality. However, the lower limb salvage and higher mortality rates at 2 years suggest that the decision-making for VQI medium- and high-risk patients may be carefully considered.

Performance of the Emergency Surgery Score (ESS) for nonelective infrainguinal open revascularization procedures (NEIOR)

BACKGROUND

The Emergency Surgery Score has been previously validated as a reliable; tool to predict postoperative outcomes in emergency general surgery. The purpose of this study was to assess the performance of the Emergency Surgery Score for infrainguinal open revascularization procedures in the nonelective setting.

METHODS

The American College of Surgeons' National Surgical Quality Improvement Program database was retrospectively analyzed for patients undergoing infrainguinal open revascularization procedures in the nonelective setting between 2015 and 2019. The performance of the Emergency Surgery Score in predicting mortality in each procedure was assessed using receiver operating characteristic analyses.

RESULTS

A total of 5,027 patients underwent infrainguinal open revascularization procedures in the nonelective setting with median age 68 (±11.66 standard deviation), with 1,666 females (33.1%). The 30-day mortality rate was 2.7%. The Emergency Surgery Score correlated with 30-day mortality (area under the curve was 0.738). The Emergency Surgery Score also predicted risk of death/discharge to hospice (area under the curve 0.756), discharge to rehab (area under the curve 0.643), renal failure (area under the curve 0.741), postintervention ventilation requirement (0.684), stroke (0.717), cardiopulmonary arrest (0.657), and septic shock (0.697). A cumulative frequency table of mortality with Emergency Surgery Score was used to partition patients into quartiles of Emergency Surgery Score ≤5, Emergency Surgery Score of 6, Emergency Surgery Score of 7 or 8, and Emergency Surgery Score ≥9. A Cochran-Armitage test showed linear trend toward increased 30-day mortality among the quartiles with increasing Emergency Surgery Score (P < .001), with quartile 4 (Emergency Surgery Score ≥10) having 13 times odds of increased 30-day mortality compared to reference quartile 1 (Emergency Surgery Score ≤4).

CONCLUSION

Emergency Surgery Score performance accurately predicts mortality for infrainguinal open revascularization procedures in the nonelective setting procedures. It may be useful for preoperative risk stratification and for national benchmarking after nonelective open lower extremity procedures.

Outcomes of a bypass-first strategy in chronic limb-threatening ischemia based on the Global Vascular Guidelines

OBJECTIVE

The Global Vascular Guidelines (GVGs) recommend initial revascularization (bypass or endovascular therapy) for chronic limb-threatening ischemia (CLTI) based on anatomical complexity and limb severity. This decision is made based on a prediction of the outcomes after endovascular intervention. This study was performed to evaluate outcomes after distal bypass in cases recommended for GVG bypass.

METHODS

A total of 239 distal bypasses for CLTI were evaluated in 195 patients with a GVG bypass recommendation treated between 2009 and 2020 at a single center in Japan. Comparisons were made between crural and pedal bypass cases.

RESULTS

The 195 patients (median age, 77 years; 67% male) underwent 133 crural bypasses (106 patients; 54%) and 106 pedal bypasses (89 patients; 46%). Hemodialysis was more common in pedal cases than in crural cases (P = .03). Hospital deaths occurred in two cases (1%) within 30 days. The whole cohort has a follow-up rate of 96% over a mean of 28 ± 26 months, with 3-year limb salvage rates of 87% and 3-year primary, assisted primary, and secondary patency rates of 40%, 65%, and 67%, all without significant differences between crural and pedal cases. The 1-year wound healing rate was 88% and tended to be higher in crural cases than in pedal cases (P = .068). The 3-year survival rate was 52% in the cohort and did not differ significantly between crural and pedal cases.

CONCLUSIONS

Patients with CLTI with a GVG bypass recommendation had acceptable limb salvage, graft patency, wound healing, and survival after distal bypass, regardless of the bypass method. These findings indicate that a GVG bypass recommendation as an initial revascularization method is valid in the real world.

Surgery or Endovascular Therapy for Chronic Limb-Threatening Ischemia

BACKGROUND

Patients with chronic limb-threatening ischemia (CLTI) require revascularization to improve limb perfusion and thereby limit the risk of amputation. It is uncertain whether an initial strategy of endovascular therapy or surgical revascularization for CLTI is superior for improving limb outcomes.

METHODS

In this international, randomized trial, we enrolled 1830 patients with CLTI and infrainguinal peripheral artery disease in two parallel-cohort trials. Patients who had a single segment of great saphenous vein that could be used for surgery were assigned to cohort 1. Patients who needed an alternative bypass conduit were assigned to cohort 2. The primary outcome was a composite of a major adverse limb event - which was defined as amputation above the ankle or a major limb reintervention (a new bypass graft or graft revision, thrombectomy, or thrombolysis) - or death from any cause.

RESULTS

In cohort 1, after a median follow-up of 2.7 years, a primary-outcome event occurred in 302 of 709 patients (42.6%) in the surgical group and in 408 of 711 patients (57.4%) in the endovascular group (hazard ratio, 0.68; 95% confidence interval [CI], 0.59 to 0.79; P<0.001). In cohort 2, a primary-outcome event occurred in 83 of 194 patients (42.8%) in the surgical group and in 95 of 199 patients (47.7%) in the endovascular group (hazard ratio, 0.79; 95% CI, 0.58 to 1.06; P = 0.12) after a median follow-up of 1.6 years. The incidence of adverse events was similar in the two groups in the two cohorts.

CONCLUSIONS

Among patients with CLTI who had an adequate great saphenous vein for surgical revascularization (cohort 1), the incidence of a major adverse limb event or death was significantly lower in the surgical group than in the endovascular group. Among the patients who lacked an adequate saphenous vein conduit (cohort 2), the outcomes in the two groups were similar. (Funded by the National Heart, Lung, and Blood Institute; BEST-CLI ClinicalTrials.gov number, NCT02060630.).

Prediction Models for Two Year Overall Survival and Amputation Free Survival After Revascularisation for Chronic Limb Threatening Ischaemia

OBJECTIVE

The aim of this study was to create prediction models for two year overall survival (OS) and amputation free survival (AFS) after revascularisation in patients with chronic limb threatening ischaemia (CLTI).

METHODS

This was a retrospective analysis of prospectively collected multicentre registry data (JAPAN Critical Limb Ischaemia Database; JCLIMB). Data from 3 505 unique patients with CLTI who had undergone revascularisation from 2013 to 2017 were extracted from the JCLIMB for the analysis. The cohort was randomly divided into development (2 861 patients) and validation cohorts (644 patients). In the development cohort, multivariable risk models were constructed to predict two year OS and AFS using Cox proportional hazard regression analysis. These models were applied to the validation cohort and their performances were evaluated using Harrell's C index and calibration plots.

RESULTS

Kaplan-Meier estimates of two year OS and AFS post-revascularisation in the whole cohort were 69% and 62%, respectively. Strong predictors for OS consisted of age, activity, malignant neoplasm, chronic kidney disease (CKD), congestive heart failure (CHF), geriatric nutritional risk index (GNRI), and sex. Strong predictors for AFS included age, activity, malignant neoplasm, CKD, CHF, GNRI, body temperature, white blood cells, urgent revascularisation procedure, and sex. Prediction models for two year OS and AFS showed good discrimination with Harrell's C indexes of 0.73 (95% confidence interval [CI] 0.69 - 0.77) and 0.72 (95% CI 0.68 - 0.76), respectively CONCLUSION: Prediction models for two year OS and AFS post-revascularisation in patients with CLTI were created. They can assist in determining treatment strategies and serve as risk adjustment modalities for quality benchmarking for revascularisation in patients with CLTI at each facility.

Age-dependent outcome of first-line endovascular and surgical revascularization strategies in chronic limb-threatening ischemia

OBJECTIVE

Chronic limb-threatening ischemia (CLTI) has a high mortality and amputation risk even after revascularization. Due to an ageing population the incidence of peripheral arterial disease is rising. However, the current age distribution in patients with CLTI and the impact of age on outcome remains unclear. For this reason we performed an age-dependent analysis of mortality, morbidity, and amputation-free survival after open surgical revascularization (OSR) and endovascular revascularization therapy (ERT) with identification of risk factors for mortality. Standardized mortality ratios (SMR) were calculated, comparing observed deaths in the study population to expected deaths based on age and gender specific mortality rates of the overall Dutch population.

METHODS

Patients revascularized for a first episode of CLTI between 2013 and 2018 were included in this multicenter retrospective cohort study. The cohort was divided in two treatment groups (OSR and ERT) who were each stratified in three age groups: early age group <65 years (G1), middle age group 65-74 years (G2) and elderly age group ≥75 years (G3).

RESULTS

During the study period 274 limbs (43.9%) were treated with OSR and 350 limbs (56.1%) with ERT. The young population (G1) is only a small part of the whole CLTI population, namely for OSR 22% and ERT 18%. The risk profile of the early age group was characterized by male sex and smoking, while the elderly age group was characterized by poor arterial runoff, tissue loss, hypertension, hypercholesterolemia, chronic kidney disease, history of heart disease, COPD and cerebrovascular disease. One year amputation rates were similar between the age groups. However, significantly higher one year mortality rates were observed in patients ≥75 years in comparison to the low mortality rates in patients <75 years. (OSR: G3 19.8% vs G2 7.1% and G1 6.7%, P = .006; ERT: G3 30.7 vs G2 12.7% and G1 7.8%, P = .001). The SMR in this elderly group equaled 3.72 after OSR and 4.04 after ERT. Independent risk factors for mortality after OSR were age, hazard ratio (HR) 1.03 (95% confidence interval (CI) 1.01-1.06; P = .006), preoperative hemoglobin level, HR 0.79 (95% CI 0.67-0.92; P = .003), tissue loss, HR 1.85; 95% CI 1.22-2.79; P = .004), cardiac history, HR 1.56 (95% CI 1.06-2.30; P = .024) and development of postoperative delirium, HR 2.75 (95% CI 1.61-4.71; P < .001) . After ERT we identified age, HR 1.06 (95% CI 1.04-1.08; P < .001), preoperative hemoglobin level, HR 0.75 (95% CI 0.65-0.87; P < .001), tissue loss, HR 1.71 (95% CI 1.15-2.53; P = .008), history of chronic obstructive pulmonary disease (COPD), HR 1.99 (95% CI 1.43-1.79; P < .001), history of cerebrovascular accident (CVA), HR 1.55 (95% CI 1.09-2.21; P = .015), the development of postoperative pneumonia, HR 2.27 (95% CI 1.24-4.16; P = .008), postoperative acute kidney injury (AKI), HR 2.42 (95% CI 1.29-4.54; P = .006) and postoperative CVA, HR 8.17 (95% CI 1.96-34.15; P = .004) as risk factors.

CONCLUSIONS

The current CLTI population consists mostly of elderly patients and only a small part is younger than 65 years. This shift in the population is important because increasing age is associated with considerable higher one year mortality rates regardless of the method of revascularization in patients with CLTI. The mortality rates in the elderly group are three to four times larger than expected in the general population. In relation to the high mortality of the elderly patient, we assume that interventions to prevent postoperative delirium and correct preoperative anemia may be warranted as they appear to be independent risk factors for mortality.

Applicability of the Vascular Quality Initiative (VQI) mortality prediction model for infrainguinal revascularization in a tertiary limb preservation center population

OBJECTIVE

Patients undergoing revascularization for chronic limb-threatening ischemia (CLTI) are at elevated risk for both mortality and limb loss. To facilitate therapeutic decision-making, a mortality prediction model derived from the Vascular Quality Initiative (VQI) database has stratified patients into low, medium, and high risk, defined by 30-day mortality estimated of ≤3%, 3-5%, or >5% and 2-year mortality estimates of ≤30%, 30-50%, or ≥50%, respectively. The purpose of this study was to compare expected mortality risk derived from this model with observed outcomes in a tertiary center.

METHODS

Consecutive patients treated at a single center between 2016 and 2019 were analyzed. Baseline demographics, approach, and mortality events were reviewed. Observed mortality was obtained using life-table methods and compared using a log-rank test with the expected mortality risk which was calculated using the VQI model.

RESULTS

This study cohort consisted of 195 revascularization procedures in 169 unique patients stratified into 128 (66%) low, 50 (26%) medium, and 17 (8%) high-risk cases based on the VQI model. 90% of revascularizations were performed for tissue loss. Compared with the VQI population, comorbidities were prevalent and included unstable angina or myocardial infarction within 6 months (6% vs. 2.4% in VQI; p<0.001), congestive heart failure (30% vs. 23%; p<0.001), and dialysis dependence (14% vs. 0.9%; p<0.001). Patients were also older (31% vs. 21% ≥80 years old; p<0.001) and more likely to be frail (45% vs. 64% independent; p<0.001). High-risk patients were more prevalent in the endovascular group (11% of 132 endovascular interventions vs. 3% of 63 bypasses; p=0.056). 30-day observed mortality exceeded expected VQI prediction model mortality in all groups, although was not statistically significant. The VQI model adequately stratified the studied population into risk groups (p<0.001). Low risk CLTI patients (65% of the overall cohort) experienced 2- year mortality of 18.9%. However, observed mortality for medium and high-risk VQI strata were similar. After a median follow-up of 28 months, medium-risk patients incurred a significantly higher mortality than predicted (53.5%±2.1% vs. 36.8%±1.1%; p=0.016).

CONCLUSIONS

The VQI mortality prediction model discriminates mortality risk after limb revascularization in CLTI, accurately identifying a majority subgroup of patients who are suitable for either open or endovascular intervention. However, it may underestimate mortality in a tertiary referral population with high comorbidity burden and was not well calibrated for the medium-risk group. It may be more appropriate to dichotomize CLTI patients who are candidates for limb salvage into an average risk and high-risk group.

Engineered clustered myoblast cell injection augments angiogenesis and muscle regeneration in peripheral artery disease

The low survival rate of administered cells due to ischemic and inflammatory environments limits the efficacy of the current regenerative cell therapy in peripheral artery disease (PAD). This study aimed to develop a new method to enhance the efficacy of cell therapy in PAD using cell sheet technology. Clustered cells (CCs) from myoblast cell sheets obtained from C57/BL6 mice were administered into ischemic mouse muscles 7 days after induction of ischemia (defined as day 0). Control groups were administered with single myoblast cells (SCs) or saline. Cell survival, blood perfusion of the limb, angiogenesis, muscle regeneration, and inflammation status were evaluated. The survival of administered cells was markedly improved in CCs compared with SCs at days 7 and 28. CCs showed significantly improved blood perfusion, augmented angiogenesis with increased density of CD31⁺/α-smooth muscle actin⁺ arterioles, and accelerated muscle regeneration, along with the upregulation of associated genes. Additionally, inflammation status was well regulated by CCs administration. CCs administration increased the number of macrophages and then induced polarization into an anti-inflammatory phenotype (CD11c^-/CD206⁺), along with the increased expression of genes associated with anti-inflammatory cytokines. Our findings suggest clinical potential of rescuing severely damaged limbs in PAD using CCs.

Association of Frailty With Treatment Selection and Long-Term Outcomes Among Patients With Chronic Limb-Threatening Ischemia

Background The optimal treatment strategy for patients with chronic limb-threatening ischemia (CLTI) is often unclear. Frailty has emerged as an important factor that can identify patients at greater risk of poor outcomes and guide treatment selection, but few studies have explored its utility among the CLTI population. We examine the association of a health record-based frailty measure with treatment choice and long-term outcomes among patients hospitalized with CLTI. Methods and Results We included patients aged >65 years hospitalized with CLTI in the Medicare Provider Analysis and Review data set between October 1, 2009 and September 30, 2015. The primary exposure was frailty, defined by the Claims-based Frailty Indicator. Baseline frailty status and revascularization choice were examined using logistic regression. Cox proportional hazards regression was used to determine the association between frailty and death or amputation, stratifying by treatment strategy. Of 85 060 patients, 35 484 (42%) were classified as frail. Frail patients had lower likelihood of revascularization (adjusted odds ratio [OR], 0.78; 95% CI, 0.75‒0.82). Among those revascularized, frailty was associated with lower likelihood of surgical versus endovascular treatment (adjusted OR, 0.76; CI, 0.72‒0.81). Frail patients experienced increased risk of amputation or death, regardless of revascularization status (revascularized: adjusted hazard ratio [HR], 1.34; CI, 1.30‒1.38; non-revascularized: adjusted HR, 1.22; CI, 1.17‒1.27). Among those revascularized, frailty was independently associated with amputation or death irrespective of revascularization strategy (surgical: adjusted HR, 1.36; CI, 1.31‒1.42; endovascular: aHR, 1.29; CI, 1.243‒1.35). Conclusions Among patients hospitalized with CLTI, frailty is an important independent predictor of revascularization strategy and longitudinal adverse outcomes.

Prognostic Significance of Preoperative Functional Independence Measure (FIM) on Long-Term Outcomes in Patients with Chronic Limb-Threatening Ischemia (CLTI)

BACKGROUND

The purpose of this study was to evaluate the effect of preoperative motor and cognitive activities of daily living (ADL) on long-term outcomes of patients with chronic limb-threatening ischemia (CLTI) after distal bypass.

METHODS

A retrospective review was performed for patients who underwent distal bypass for CLTI from 2013 to 2019 at multiple centers in Japan. Comparisons were made among patients with high and low motor and cognitive ADL based on the functional independence measure (FIM). The primary endpoint was limb salvage and the secondary endpoints were survival, amputation free survival (AFS), major adverse limb events (MALE), readmission, and wound healing.

RESULTS

A total of 226 distal bypasses were performed in 185 patients (169 males; median age, 76 years; diabetes mellitus, 70%; end-stage renal disease with hemodialysis, 40%). The patients were divided into high (n = 93, 50%) and low (n = 92, 50%) FIM-motor cases, and high (n = 157, 85%) and low (n = 28, 15%) FIM-cognitive cases. FIM-motor (high vs. low) and FIM-cognitive (high vs. low) were not significantly associated with limb salvage, freedom from MALE, freedom from readmission, and wound healing. The 1- and 3-year survival rates were significantly lower in low FIM-motor cases (93% vs. 70% at 1 year, 73% vs. 46% at 3 years, P = 0.0011); and in low FIM-cognitive cases (87% vs. 50% at 1 year, 63% vs. 45% at 3 years, P < 0.001). The 1- and 3-year AFS rates were significantly lower in low FIM-motor cases (92% vs. 67% at 1 year, 69% vs. 44% at 3 years, P < 0.001); and in low FIM-cognitive cases (85% vs. 49% at 1 year, 59% vs. 44% at 3 years, P < 0.001). In multivariate analysis, independent risk factors for survival were hemodialysis (HR = 2.17; 95% confidence interval (CI), 1.23-3.83; P = .0078), low FIM-cognitive (HR = 3.45; 95% CI, 1.78-6.71; P < 0.001), and ejection fraction (HR = 0.98; 95% CI, 0.95-0.99; P = 0.019).

CONCLUSIONS

FIM-motor and FIM-cognitive were predictive factors for long-term survival and AFS of CLTI patients after distal bypass, but had no influence on limb salvage, MALE, readmission, and wound healing. These results suggest that the motor and cognitive status of ADL should be assessed using FIM before distal bypass for patients with CLTI.

High lipoprotein(a) is associated with major adverse limb events after femoral artery endarterectomy

BACKGROUNDS AND AIMS

Elevated lipoprotein(a) (Lp[a]) has been identified as a causal risk factor for cardiovascular disease including peripheral arterial disease (PAD). Although Lp(a) is associated with the diagnosis of PAD, it remains elusive whether there is an association of Lp(a) with cardiovascular and limb events in patients with severe PAD.

METHODS

Preoperative plasma Lp(a) levels were measured in 384 consecutive patients that underwent iliofemoral endarterectomy and were included in the Athero-Express biobank. Our primary objective was to assess the association of Lp(a) levels with Major Adverse Limb Events (MALE). Our secondary objective was to relate Lp(a) levels to Major Adverse Cardiovascular Events (MACE) and femoral plaque composition that was acquired from baseline surgery.

RESULTS

During a median follow-up time of 5.6 years, a total of 225 MALE were recorded in 132 patients. Multivariable analysis, including history of peripheral intervention, age, diabetes mellitus, end stage renal disease and PAD disease stages, showed that Lp(a) was independently associated with first (HR of 1.36 (95% CI 1.02-1.82) p = .036) and recurrent MALE (HR 1.36 (95% CI 1.10-1.67) p = .004). A total of 99 MACE were recorded but Lp(a) levels were not associated with MACE.sLp(a) levels were significantly associated with a higher presence of smooth muscle cells in the femoral plaque, although this was not associated with MALE or MACE.

CONCLUSIONS

Plasma Lp(a) is independently associated with first and consecutive MALE after iliofemoral endarterectomy. Hence, in patients who undergo iliofemoral endarterectomy, Lp(a) could be considered as a biomarker to enhance risk stratification for future MALE.

Income Deprivation and Groin Wound Surgical Site Infection: Cross-Sectional Analysis from the Groin Wound Infection after Vascular Exposure Multicenter Cohort Study

Background: Living in deprived areas is associated with poorer outcomes after certain vascular procedures and surgical site infection in other specialties. Our primary objective was to determine whether living in more income-deprived areas was associated with groin wound surgical site infection after arterial intervention. Secondary objectives were to determine whether living in more income-deprived areas was associated with mortality and clinical consequences of surgical site infection. Methods: Postal code data for patients from the United Kingdom who were included in the Groin Wound Infection after Vascular Exposure (GIVE) multicenter cohort study was used to determine income deprivation, based on index of multiple deprivation (IMD) data. Patients were divided into three IMD groups for descriptive analysis. Income deprivation score was integrated into the final multivariable model for predicting surgical site infection. Results: Only patients from England had sufficient postal code data, analysis included 772 groin incisions (624 patients from 22 centers). Surgical site infection occurred in 9.7% incisions (10.3% of patients). Surgical site infection was equivalent between income deprivation tertiles (tertile 1 = 9.5%; tertile 2 = 10.3%; tertile 3 = 8.6%; p = 0.828) as were the clinical consequences of surgical site infection and mortality. Income deprivation was not associated with surgical site infection in multivariable regression analysis (odds ratio [OR], 0.574; 95% confidence interval [CI], 0.038-8.747; p = 0.689). Median age at time of procedure was lower for patients living in more income-deprived areas (tertile 1 = 68 years; tertile 2 = 72 years; tertile 3 = 74 years; p < 0.001). Conclusions: We found no association between living in an income-deprived area and groin wound surgical site infection, clinical consequences of surgical site infection and mortality after arterial intervention. Patients living in more income-deprived areas presented for operative intervention at a younger age, with similar rates of comorbidities to patients living in less income-deprived areas.

Revascularization Strategies for Acute and Chronic Limb Ischemia

Chronic limb-threatening ischemia requires aggressive risk factor management and a thoughtful approach to the complex decision of best strategy for revascularization. Patients often have multilevel disease amenable to endovascular, open surgical, or hybrid approaches. Limited high-quality evidence is available to support a specific strategy; randomized trials are ongoing. Acute limb ischemia is associated with a high risk of limb loss and mortality. Catheter-directed thrombolysis is mainstay of therapy in patients with marginally threatened limbs, whereas those immediately threatened with motor deficits require more rapid restoration of flow with open or endovascular techniques that can establish flow in single setting.

A single center's 15-year experience with palliative limb care for chronic limb threatening ischemia in frail patients

OBJECTIVE

Our institution's multidisciplinary Prevention of Amputation in Veterans Everywhere (PAVE) program allocates veterans with critical limb threatening ischemia (CLTI) to immediate revascularization, conservative, primary amputation or palliative limb care based on previously published criteria. These four groups align with the approaches outlined by the Global Guidelines for management of CLTI. The current study delineates the natural history of the palliative limb care group of patients and quantifies procedural risks and outcomes.

METHODS

Veterans prospectively enrolled into the palliative limb cohort of our PAVE program between January 2005 and January 2020 were analyzed. The primary outcome was mortality. Secondary outcomes included overall and limb-related readmissions, limb loss and wound healing. Clinical Frailty Score (CFS) was calculated and 5-year expected mortalities were estimated using the Veterans Administration Quality Enhancement Research Initiative (VA QUERI) tool. Regression analysis was performed to establish associations among the following variables: mortality, WIfI score, Clinical Frailty Score, overall admissions and limb-related admissions.

RESULTS

The PAVE program enrolled 1158 limbs over 15 years. 157 (13.5%) limbs in 145 patients were allocated to the palliative limb care group. The overall mortality of the group was 88.2% (median 3.5 months; range 0-91 months). Of the patients that expired, 50% (n=64) died within 3 months of enrollment. The predicted 5-year mortality for the group was 66%. The average frailty score of the group was 6.2, denoting someone who is moderately to severely frail. Based on CFS, 106 patients were considered frail while 39 were considered not frail. There was no difference in mortality between frail and non- frail patients, however there was a statistically significant difference in early mortality (<3 months), 56.2% vs 37.5% (p = 0.032), respectively. The 30-day limb-related readmission rate was 4.7%. Eventual major amputation was necessary in 18 (11.5%) limbs. Wound healing occurred in 30 patients (20.6%). Regression analysis demonstrated no association between frailty score and mortality (r = 0.55, p = 0.159) or between WIfI score and mortality (r = 0.0165, p = 0.98). There was a significant association between WIfI score and limb-related admissions (r = 0.97, p <0.001).

CONCLUSION

Frail, chronic limb threatening ischemia patients have a high early mortality and a low risk of limb-related complications. They also have a low incidence of deferred primary amputation or limb-related readmissions. In our cohort, the vast majority of patients died within a few months of enrollment without needing an amputation. A comprehensive approach to the management of CLTI patients should include a palliative limb care option as a significant proportion of these patients have limited survival and can potentially avoid unnecessary surgery or major amputation.

Lower Extremity Peripheral Artery Disease: Contemporary Epidemiology, Management Gaps, and Future Directions: A Scientific Statement From the American Heart Association

Lower extremity peripheral artery disease (PAD) affects >230 million adults worldwide and is associated with increased risk of various adverse clinical outcomes (other cardiovascular diseases such as coronary heart disease and stroke and leg outcomes such as amputation). Despite its prevalence and clinical importance, PAD has been historically underappreciated by health care professionals and patients. This underappreciation seems multifactorial (eg, limited availability of the first-line diagnostic test, the ankle-brachial index, in clinics; incorrect perceptions that a leg vascular disease is not fatal and that the diagnosis of PAD would not necessarily change clinical practice). In the past several years, a body of evidence has indicated that these perceptions are incorrect. Several studies have consistently demonstrated that many patients with PAD are not receiving evidence-based therapies. Thus, this scientific statement provides an update for health care professionals regarding contemporary epidemiology (eg, prevalence, temporal trends, risk factors, and complications) of PAD, the present status of diagnosis (physiological tests and imaging modalities), and the major gaps in the management of PAD (eg, medications, exercise therapy, and revascularization). The statement also lists key gaps in research, clinical practice, and implementation related to PAD. Orchestrated efforts among different parties (eg, health care providers, researchers, expert organizations, and health care organizations) will be needed to increase the awareness and understanding of PAD and improve the diagnostic approaches, management, and prognosis of PAD.

Technical Success and Mid-Term Outcomes of Endovascular Revascularization of Tibio-Peroneal Trunk Lesions

Tibio-peroneal trunk (TPT) lesions are usually categorized as ‘complex’ in anatomical classifications, which leads to the perception that endovascular therapy (EVT) will be challenging and the outcome most likely poor. This multicenter, retrospective cohort study investigates the efficacy of the EVT of TPT lesions in patients with chronic limb threatening ischemia (CLTI) or an infrapopliteal bypass at risk. The primary endpoint was limb-salvage. The secondary outcomes were technical success, freedom from clinically driven target lesion revascularization (CD-TLR), overall survival, and amputation-free survival. A total of 107 TPT lesions were treated in 101 patients. At 3 years, the limb-salvage rate was 76.4% (95% CI 66.0–86.8%). Technical success was achieved in 96.3% of cases. The freedom from CD-TLR, amputation-free survival, and overall survival at 3 years were 53.0% (95% CI 38.1–67.9%), 33.6% (95% CI 23.0–44.2%), and 47.7% (95% CI 36.1–59.3%), respectively. Reintervention significantly increased the hazard ratio for amputation by 7.65 (95% CI 2.50–23.44, p < 0.001). Our results show that the EVT of both isolated and complex TPT lesions is associated with high technical success and acceptable limb-salvage rates, with reintervention being a major risk factor for amputation. Moreover, mid-term mortality rate was relatively high. In future revisions of the anatomical grading scales, the classification of TPT lesions as highly complex should be reconsidered.

The Global Limb Anatomic Staging System (GLASS) for CLTI: Improving Inter-Observer Agreement

Objective: The 2020 Global Vascular Guidelines aim at improving decision making in Chronic Limb-Threatening Ischemia (CLTI) by providing a framework for evidence-based revascularization. Herein, the Global Limb Anatomic Staging System (GLASS) serves to estimate the chance of success and patency of arterial pathway revascularization based on the extent and distribution of the atherosclerotic lesions. We report the preliminary feasibility results and observer variability of the GLASS. GLASS is a part of the new global guideline and posed as a promising additional tool for EBR strategies to predict the success of lower extremity arterial revascularization. This study reports on the consistency of GLASS scoring to maximize inter-observer agreement and facilitate its application. Methods: GLASS separately scores the femoropopliteal (FP) and infrapopliteal (IP) segment based on stenosis severity, lesion length and the extent of calcification within the target artery pathway (TAP). In our stepwise approach, we used two angiographic datasets. Each following step was based on the lessons learned from the previous step. The primary outcome was inter-observer agreement measured as Cohen’s Kappa, scored by two (step 1 + 2) and four (step 3) blinded and experienced observers, respectively. Steps 1 (n = 139) and 2 (n = 50) were executed within a dataset of a Dutch interventional RCT in CLTI. Step 3 (n = 100) was performed in randomly selected all-comer CLTI patients from two vascular centers in the United States. Results: In step 1, kappa values were 0.346 (FP) and 0.180 (IP). In step 2, applied in the same dataset, the use of other experienced observers and a provided TAP, resulted in similar low kappa values 0.406 (FP) and 0.089 (IP). Subsequently, in step 3, the formation of an altered stepwise approach using component scoring, such as separate scoring of calcification and adding a ruler to the images resulted in kappa values increasing to 0.796 (FP) and 0.730 (IP). Conclusion: This retrospective GLASS validation study revealed low inter-observer agreement for unconditioned scoring. A stepwise component scoring provides acceptable agreement and a solid base for further prospective validation studies to investigate how GLASS relates to treatment outcomes.

Ambulatory Status Over Time after Revascularization in Patients with Chronic Limb-Threatening Ischemia

Aim: Maintaining functional status through revascularization is a major goal in patients with chronic limb-threatening ischemia (CLTI). Nevertheless, there is a lack of clarity on the impact of revascularization on mobility over time. This study examined ambulatory status over time after revascularization and predictors of ambulation loss in CLTI patients.

Methods: We used a clinical database established by the Surgical reconstruction versus Peripheral INtervention in pAtients with critical limb isCHemia study, a prospective, multicentre, observational study including patients with CLTI. The primary endpoint was mobility over time.

Results: Of the 381 patients, the ambulatory proportion at baseline was 71%. The proportion gradually decreased, finally reaching 40% at 36 months. In non-ambulatory patients at revasacularisation, approximately 20-40% of patients achieved ambulation. Multivariate analysis confirmed that age, impaired mobility before CLTI onset and at revascularization, renal failure on dialysis, and WIfI clinical stage 4 were positively associated with ambulation loss at either specific or all time points, whereas male sex and surgical reconstruction were inversely associated with the outcomes at specific time points.

Conclusion: Mobility in the overall population gradually decreased, whereas the number of deceased patients increased. Advanced age, impaired mobility before CLTI onset and at revascularization, renal failure on dialysis, and WIfI stage 4 were associated with ambulation loss at almost all points after revascularization.

Diagnosis of silent coronary ischemia with selective coronary revascularization might improve 2-year survival of patients with critical limb-threatening ischemia

BACKGROUND

Patients with critical limb-threatening ischemia (CLTI) have had poor long-term survival after lower extremity revascularization owing to coexistent coronary artery disease. A new cardiac diagnostic test, coronary computed tomography-derived fractional flow reserve (FFR_CT), can identify patients with ischemia-producing coronary stenosis who might benefit from coronary revascularization. We sought to determine whether the diagnosis of silent coronary ischemia before limb salvage surgery with selective postoperative coronary revascularization can reduce the incidence of adverse cardiac events and improve the survival of patients with CLTI compared with standard care.

METHODS

Patients with CLTI and no cardiac history or symptoms who had undergone preoperative testing to detect silent coronary ischemia with selective postoperative coronary revascularization (group I) were compared with patients with standard preoperative cardiac clearance and no elective postoperative coronary revascularization (group II). Both groups received guideline-directed medical care. Lesion-specific coronary ischemia in group I was defined as FFR_CT of ≤0.80 distal to a stenosis, with severe ischemia defined as FFR_CT of ≤0.75. The endpoints included all-cause death, cardiovascular (CV) death, myocardial infarction (MI), major adverse CV events (i.MACE; CV death, MI, unplanned coronary revascularization, stroke) through 2 years of follow-up.

RESULTS

Groups I (n = 111) and II (n = 120) were similar in age (66 ± 9 vs 66 ± 7 years), gender (78% vs 83% men), comorbidities, and surgery performed. In group I, unsuspected, silent coronary ischemia was found in 71 of 103 patients (69%), with severe ischemia in 58% and left main coronary ischemia in 8%. Elective postoperative coronary revascularization was performed in 47 of 71 patients with silent ischemia (66%). In group II, the status of silent coronary ischemia was unknown. The median follow-up was >2 years for both groups. The 2-year outcomes for groups I and II were as follows: all-cause death, 8.1% and 20.0% (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.18-0.84; P = .016); CV death, 4.5% and 13.3% (HR, 0.32; 95% CI, 0.11-0.88; P = .028); MI, 6.3% and 17.5% (HR, 0.33; 95% CI, 0.14-0.79; P = .012); and major adverse CV events, 10.8% and 23.3% (HR, 0.44; 95% CI, 0.22-0.88; P = .021), respectively.

CONCLUSIONS

The preoperative evaluation of patients with CLTI and no known coronary artery disease using coronary FFR_CT revealed silent coronary ischemia in two of every three patients. Selective coronary revascularization of patients with silent coronary ischemia after recovery from limb salvage surgery resulted in fewer CV deaths and MIs and improved 2-year survival compared with patients with CLTI who had received standard cardiac evaluation and care. Prospective controlled studies are required to further define the role of FFR_CT in the evaluation and treatment of patients with CLTI.

Risk prediction model for early outcomes of revascularization for chronic limb-threatening ischaemia

BACKGROUND

Quantifying the risks and benefits of revascularization for chronic limb-threatening ischaemia (CLTI) is important. The aim of this study was to create a risk prediction model for treatment outcomes 30 days after revascularization in patients with CLTI.

METHODS

Consecutive patients with CLTI who had undergone revascularization between 2013 and 2016 were collected from the JAPAN Critical Limb Ischemia Database (JCLIMB). The cohort was divided into a development and a validation cohort. In the development cohort, multivariable risk models were constructed to predict major amputation and/or death and major adverse limb events using least absolute shrinkage and selection operator logistic regression. This developed model was applied to the validation cohort and its performance was evaluated using c-statistic and calibration plots.

RESULTS

Some 2906 patients were included in the analysis. The major amputation and/or mortality rate within 30 days of arterial reconstruction was 5.0 per cent (144 of 2906), and strong predictors were abnormal white blood cell count, emergency procedure, congestive heart failure, body temperature of 38°C or above, and hemodialysis. Conversely, moderate, low or no risk in the Geriatric Nutritional Risk Index (GNRI) and ambulatory status were associated with improved results. The c-statistic value was 0.82 with high prediction accuracy. The rate of major adverse limb events was 6.4 per cent (185 of 2906), and strong predictors were abnormal white blood cell count and body temperature of 38°C or above. Moderate, low or no risk in the GNRI, and age greater than 84 years were associated with improved results. The c-statistic value was 0.79, with high prediction accuracy.

CONCLUSION

This risk prediction model can help in deciding on the treatment strategy in patients with CLTI and serve as an index for evaluating the quality of each medical facility.

Association Rule Mining and Prognostic Stratification of 2-Year Longevity in Octogenarians Undergoing Endovascular Therapy for Lower Extremity Arterial Disease: Observational Cohort Study

Background

Two-year longevity is a crucial consideration in revascularization strategies for patients with symptomatic lower extremity arterial disease (LEAD). However, factors associated with 2-year longevity and risk stratification in octogenarians or nonagenarians have been underreported.

Objective

This paper aims to investigate the associated variables and stratify the 2-year prognosis in older patients with LEAD.

Methods

We performed logistic regression and association rule mining based on the Apriori algorithm to discover independent variables and validate their associations with 2-year longevity. Malnutrition, inflammation, and stroke factors were identified. C statistics and Kaplan-Meier analysis were used to assess the impact of different numbers of malnutrition, inflammation, and stroke factors on 2-year longevity.

Results

We recruited a total of 232 octogenarians or nonagenarians (mean age 85 years, SD 4.2 years) treated with endovascular therapy. During the study period, 81 patients died, and 27 of those (33%) died from a cardiac origin within 2 years. Association rules analysis showed the interrelationships between 2-year longevity and the neutrophil-lymphocyte ratio (NLR) and nutritional status as determined by the Controlling Nutritional Status (CONUT) score or Geriatric Nutritional Risk Index (GNRI). The cut-off values of NLR, GNRI, and CONUT were ≥3.89, ≤90.3, and >3, respectively. The C statistics for the predictive power for 2-year longevity were similar between the CONUT score and the GNRI-based models (0.773 vs 0.760; P=.57). The Kaplan-Meier analysis showed that 2-year longevity was worse as the number of malnutrition, inflammation, and stroke factors increased from 0 to 3 in both the GNRI-based model (92% vs 68% vs 46% vs 12%, respectively; P<.001) and the CONUT score model (87% vs 75% vs 49% vs 10%, respectively; P<.001). The hazard ratio between those with 3 factors and those without was 18.2 (95% CI 7.0-47.2; P<.001) in the GNRI and 13.6 (95% CI 5.9-31.5; P<.001) in the CONUT score model.

Conclusions

This study demonstrated the association and crucial role of malnutrition, inflammation, and stroke factors in assessing 2-year longevity in older patients with LEAD. Using this simple risk score might assist clinicians in selecting the appropriate treatment.

Sinusoidal changes in transcutaneous oxygen pressure, suggesting Cheyne-Stokes respiration, are frequent and of poor prognosis among patients with suspected critical limb ischemia

BACKGROUND AND AIMS

Transcutaneous oxygen pressure (TcpO₂) is used in patients with suspected critical limb ischemia (CLI). Sinusoidal changes (SC~) in TcpO₂ are found in patients with Cheyne-Stokes respiration (CSR). We aimed to determine the characteristics of TcpO₂ changes at rest in patients with suspected CLI, define the objective criteria for SC ~ TcpO₂ patterns (SC+), and estimate the prevalence of SC+ in our population and its impact on the outcome.

METHODS

We retrospectively analyzed 300 chest TcpO₂ recordings performed in a 16-month period. We determined the presence/absence of SC ~ TcpO₂ by visual analysis. We determined the acceptable error in the regularity of peaks of the cross-correlation with ROC curve analysis, among patients with typical SC ~ TcpO₂ and non-sinusoidal patterns. Then, we defined SC + as a minimum of five peaks, a standard deviation of TcpO₂ >1.25 mmHg, an error in regularity of peaks of the cross-correlation < 10%, and a cycle length between 30 and 100 s. In patients included until October 2019, we compared the outcome as a function of SC + or SC- with Cox models.

RESULTS

Mathematical detection of SC + found that 43 patients (14.3%) fulfilled all four defined criteria at the chest level, but only 23 did so at the limb level. In the follow-up of 207 patients, the presence of Sc ~ TcpO₂ at the chest significantly increased the risk of mortality: hazard ratio: 2.69 [95%CI: 1.37-5.30]; p < 0.005.

CONCLUSIONS

SC ~ TcpO₂ is frequent, and is associated with a poor outcome in patients with suspected CLI.

Lower Extremity Revascularization for Chronic Limb-Threatening Ischemia among Patients at the Extremes of Age

BACKGROUND

Patients with chronic limb-threatening ischemia (CLTI) at the extremes of age are thought to have distinct risk factor profiles and poor outcomes after lower extremity revascularization (LER). The aim of this study is to examine the relationships among age, risk factor profiles, and outcomes of LER in patients with CLTI in a large database focusing on the extreme age groups.

METHODS

Patients undergoing LER for CLTI in the Vascular Quality Initiative suprainguinal bypass, infrainguinal bypass, and peripheral vascular intervention files were reviewed through 2019. Patients were stratified into 3 groups: premature peripheral artery disease (PAD) (≤50 years old), 51-84 years old, and elderly (≥85 years old). Trends in major amputation and mortality by age group were analyzed.

RESULTS

There were 156,513 patients who underwent LER for CLTI. Of these, 9,063 (5.79%) patients had premature PAD, 131,694 (84.14%) patients were 51-84 years old, and 15,756 (10.07%) were elderly. Patients with premature PAD were more likely to have insulin-dependent diabetes, be dialysis-dependent, and be active smokers compared to patients 51-84 years old and the elderly. Elderly patients were more likely to undergo an endovascular procedure for tissue loss compared to younger groups. Perioperative and 1-year major amputation rates were highest among patients with premature PAD and decreased with increasing age (P < 0.001), while perioperative and 1-year mortality increased with age (P < 0.001). On multivariable analysis, premature PAD was associated with an increased risk of major amputation (odds ratio, OR = 1.41 [1.22-1.62]), while elderly age was associated with decreased odds of major amputation compared to patients 51-84 years old (OR = 0.61 [0.51-0.73]).

CONCLUSIONS

Patients at the extremes of age have significantly different outcomes after LER for CLTI. Although mortality increases with age, the risk of major amputation decreases. Patients with premature PAD constitute a group of patients with a high risk of perioperative and 1-year major amputation.

Predictive Model for Postoperative Ambulatory Function after Lower Extremity Bypass in Chronic Limb-Threatening Ischemia

BACKGROUND

In chronic limb-threatening ischemia, maintenance or recovery of ambulatory function is an important goal of treatment. This study aimed to develop a predictive model for ambulatory ability 1 year after bypass based on preoperative risk factors, including the Wound, Ischemia, and foot Infection (WIfI) classification.

METHODS

We analyzed 146 patients with chronic limb-threatening ischemia (154 limbs) who underwent bypass to below the knee arteries. The patients were classified into 2 groups based on ambulatory status 1 year postoperatively: postoperative ambulation (99 patients, 104 limbs) and postoperative nonambulation (47 patients, 50 limbs). Various factors associated with postoperative ambulation were analyzed and a predictive model of postoperative ambulation was developed.

RESULTS

Multivariate logistic regression analysis detected preoperative nonambulatory status, functional nonindependence in daily living, older age, WIfI wound grade 3, chronic obstructive pulmonary disease, and hemodialysis as independent risk factors for postoperative nonambulation. The predictive scoring model (scores ranging from -5.0 to 4.4) comprising these risk factors discriminated the postoperative ambulatory status well: the probabilities of postoperative ambulatory ability were ≥85% in those with a score ≤-2, 50% in those with a score of zero, and ≤15% in those with a score ≥2. The area under the receiver operating characteristic curve was 0.898, indicating good performance of the model.

CONCLUSIONS

Preoperative nonambulatory status, functional nonindependence, advanced age, high WIfI wound grade, chronic obstructive pulmonary disease, and hemodialysis were important predictors of postoperative nonambulatory status. The predictive model will help us identify patients who will benefit from bypass surgery.