Major adverse limb events and major adverse cardiac events after contemporary lower extremity bypass and infrainguinal endovascular intervention in patients with claudication

Supervised Exercise Therapy for Intermittent Claudication: A Propensity Score Matched Analysis of Retrospective Data on Long Term Cardiovascular Outcomes

OBJECTIVE

This study aimed to explore the long term outcomes of patients with intermittent claudication (IC) who completed supervised exercise therapy (SET) vs. those who declined or prematurely discontinued SET, focusing on the incidence of chronic limb threatening ischaemia (CLTI), revascularisation, major adverse limb events (MALE), and major adverse cardiovascular events (MACE).

METHODS

A retrospective registry analysis of consecutive patients with IC who were referred for SET between March 2015 and August 2016 and followed up for a minimum of five years. Serial univariable analysis and logistic regression were performed to identify the statistically significant clinical variables that were independent predictors of each outcome measure. The resulting statistically significant variables were used to guide 1:1 propensity score matching (PSM) using the nearest neighbour method with a calliper of 0.2. Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between SET and the outcomes of interest.

RESULTS

Two hundred and sixty-six patients were referred to SET between March 2015 and August 2016. Of these, 64 patients completed SET and 202 patients did not. After PSM, 49 patients were analysed in each cohort. The Cox proportional hazards analysis revealed a significant association between completion of SET and revascularisation requirement (HR 0.46 95% CI 0.25 - 0.84; p = .011), completion of SET and progression to CLTI (HR 0.091, 95% CI 0.04 - 0.24; p < .001), completion of SET and MACE (HR 0.52; 95% CI 0.28 - 0.99; p = .05) and completion of SET and MALE (HR 0.28, 95% CI 0.13 - 0.65; p = .003). The Harrell's C index for all of these models was greater than 0.75, indicating good predictive accuracy.

CONCLUSION

Completion of SET is associated with better outcomes in patients who completed SET compared with patients who declined or discontinued SET with respect to clinically important cardiovascular outcomes over seven years.

Short-Term Outcomes and Efficacy of Percutaneous Deep Vein Arterialization for No-Option Critical Limb Ischemia: A Systematic Review and Meta-Analysis

BACKGROUND

Percutaneous deep vein arterialization (pDVA) is considered a treatment modality in patients with no-option critical limb ischemia. However, there is still a paucity of evidence regarding its safety and efficacy.

DATA SOURCES

MEDLINE (via PubMed), Embase and Web of Science databases as well as the CENTRAL registry up to the end of June 2023.

METHODS

This review adhered to the PRISMA guidelines (PROSPERO registration no. CRD42023445171). The risk of bias was assessed using the methodological index for non-randomized studies (MINORS). Primary endpoints included technical success, overall survival and limb salvage during the follow-up. Amputation-free survival at 30 days, 6 months and 1 year as well as complete wound healing, major adverse limb events and reintervention were investigated as secondary outcomes.

RESULTS

Five observational studies, comprising 208 patients (142 Rutherford class 5/77 Rutherford class 6), were included. MINORS revealed a low risk of bias. The meta-analysis reached a pooled technical success rate of 96.2% (95% CI: 91.5-98.4), an overall survival of 82.8% (95% CI: 70.5-95.2) and a limb salvage rate of 77.2% (95% CI: 65.2-89.1) during the follow-up. The amputation-free survival at 30 days, 6 months and 1 year was 87.8%, 68.7% and 65.6%, respectively. Furthermore, pDVA resulted in a complete wound healing rate of 53.4% (95% CI: 30.3-76.5). The pooled reintervention rate was as high as 46.7% (37.1-56.3%).

CONCLUSIONS

PDVA seems a feasible bail-out strategy for patients with no option for routine treatment of CLTI. However, due to the small number of studies, the strength of the evidence is low.

Tailored risk assessment and forecasting in intermittent claudication

BACKGROUND

Guidelines recommend cardiovascular risk reduction and supervised exercise therapy as the first line of treatment in intermittent claudication, but implementation challenges and poor patient compliance lead to significant variation in management and therefore outcomes. The development of a precise risk stratification tool is proposed through a machine-learning algorithm that aims to provide personalized outcome predictions for different management strategies.

METHODS

Feature selection was performed using the least absolute shrinkage and selection operator method. The model was developed using a bootstrapped sample based on patients with intermittent claudication from a vascular centre to predict chronic limb-threatening ischaemia, two or more revascularization procedures, major adverse cardiovascular events, and major adverse limb events. Algorithm performance was evaluated using the area under the receiver operating characteristic curve. Calibration curves were generated to assess the consistency between predicted and actual outcomes. Decision curve analysis was employed to evaluate the clinical utility. Validation was performed using a similar dataset.

RESULTS

The bootstrapped sample of 10 000 patients was based on 255 patients. The model was validated using a similar sample of 254 patients. The area under the receiver operating characteristic curves for risk of progression to chronic limb-threatening ischaemia at 2 years (0.892), risk of progression to chronic limb-threatening ischaemia at 5 years (0.866), likelihood of major adverse cardiovascular events within 5 years (0.836), likelihood of major adverse limb events within 5 years (0.891), and likelihood of two or more revascularization procedures within 5 years (0.896) demonstrated excellent discrimination. Calibration curves demonstrated good consistency between predicted and actual outcomes and decision curve analysis confirmed clinical utility. Logistic regression yielded slightly lower area under the receiver operating characteristic curves for these outcomes compared with the least absolute shrinkage and selection operator algorithm (0.728, 0.717, 0.746, 0.756, and 0.733 respectively). External calibration curve and decision curve analysis confirmed the reliability and clinical utility of the model, surpassing traditional logistic regression.

CONCLUSION

The machine-learning algorithm successfully predicts outcomes for patients with intermittent claudication across various initial treatment strategies, offering potential for improved risk stratification and patient outcomes.

Revascularization for claudication: Changing the natural history of a benign disease!

OBJECTIVE

The benign natural history of intermittent claudication was first documented in 1960 and has been reconfirmed in several subsequent studies. Excellent outcomes in patients with intermittent claudication can be achieved with exercise therapy and optimal medical management. Professional society guidelines have clearly stated that revascularization procedures should be performed only in patients with incapacitating claudication who have failed conservative therapy. Despite these guidelines, revascularization procedures, primarily percutaneous interventions, have been increasingly utilized in patients with claudication. Many of these patients are not even offered an attempt at medical therapy, and those who are often do not undergo a full course of treatment. Many studies document significant reintervention rates following revascularization, which are associated with increased rates of acute and chronic limb ischemia that may result in significant rates of amputation. The objectives of this study were to compare outcomes of conservative therapy to those seen in patients undergoing revascularization procedures and to determine the impact of revascularization on the natural history of claudication.

METHODS

Google Scholar and PubMed were searched for manuscripts on the conservative management of claudication and for those reporting outcomes following revascularization for claudication.

RESULTS

Despite early improvement in claudication symptoms following revascularization, multiple studies have demonstrated that long-term outcomes following revascularization are often no better than those obtained with conservative therapy. High reintervention rates (up to 43% for tibial atherectomies) result in high rates of both acute and chronic limb ischemia as compared with those patients undergoing medical therapy. In addition, amputation rates as high as 11% on long-term follow-up are seen in patients undergoing early revascularization. These patients also have a higher incidence of adverse cardiovascular events such as myocardial infarctions compared with patients treated medically.

CONCLUSIONS

Revascularization procedures negatively impact the natural history of claudication often resulting in multiple interventions, an increase in the incidence of acute and chronic limb ischemia, and an increased risk of amputation. Accordingly, informed consent requires that all patients undergoing early revascularization must be appraised of the potential negative impact of revascularization on the natural history of claudication.

Prosthetic Conduit Use Does Not Adversely Impact Outcomes after Open Repair of Popliteal Artery Aneurysms

BACKGROUND

Single segment, greater saphenous vein (GSV) conduit is considered the optimal bypass conduit among patients undergoing bypass surgery for peripheral artery disease (PAD). While this data has been extrapolated to patients undergoing bypass for popliteal artery aneurysms (PAAs), the pathophysiology of PAA is inherently different when compared to PAD, and the impact of conduit type on long-term outcomes after open repair of PAA remains unclear.

METHODS

A multicenter database of five regional hospitals was retrospectively reviewed for all patients with PAA undergoing open surgical repair. Data were collected on demographic information, operative details, medications, and postoperative outcomes. Kaplan-Meier curves were used to compare freedom from major adverse limb events (MALE) following GSV versus prosthetic bypass. Cox proportional hazards model was used to identify patient-level characteristics associated with MALE, which was defined as major ipsilateral limb amputation or reintervention for graft patency.

RESULTS

From 1999 to 2020, a total of 101 patients with PAA underwent open exclusion and bypass surgery. Median follow-up period was 4.2 years (interquartile range, 1.3-7.4 years), and complete data were available for 99 (98.0%) patients. The majority of patients were male (99.0%) and Caucasian (93.9%). Only 11.1% of procedures were emergent, with the remainder (88.9%) being elective. All patients underwent medial exposure with a below-knee popliteal bypass target (100%). Bypass conduits included GSV (69.7%), prosthetic conduit (28.3%), and 2 (2.0%) alternative conduits (one spliced arm vein, one cryopreserved vein). Patients undergoing prosthetic bypass were older (72 vs. 66 years, P = 0.001) and had similar rates of medical comorbidities. Compared with the GSV group, patients with prosthetic conduits were more frequently placed on postoperative anticoagulation (60.7% vs. 23.2%, P < 0.001). Conduit type did not impact postoperative complication rates (P = NS each). MALE rates were low overall (19.2% at 2 years), and similar when stratified by conduit type (log rank P = 0.47). On multivariable analysis, emergent bypass was associated with MALE (hazard ratio [HR] 5.73, 95% confidence interval [CI] 2.07-15.85, P < 0.001). Prosthetic conduit usage (HR 1.00, 95% CI, 0.40-2.51, P = 0.99) and postoperative anticoagulation (HR 1.02, 95% CI 0.42-2.50, P = 0.97) were not associated with MALE.

CONCLUSIONS

Open repair of PAA is associated with excellent long-term outcomes. Prosthetic bypass is a comparable alternative to autogenous conduit for below-knee popliteal bypass targets, and lack of suitable GSV should not prohibit open surgical repair when indicated.

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.

Lack of patient-centered evaluation of outcomes in intermittent claudication literature

BACKGROUND

Peripheral arterial disease, characterized as arterial atherosclerotic disease, can lead to insufficient flow in the lower extremities and ischemia, with the most common clinical manifestation being intermittent claudication (IC). In 2022, the Society for Vascular Surgery (SVS) developed appropriate use criteria for the management of IC that used this systematic review as a source of evidence. The objective of this study is to synthesize the findings of the systematic review and identify evidence gaps.

METHODS

A comprehensive search of literature databases including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus was conducted from January 1, 2000, to November 30, 2022. Noncomparative and comparative observational studies and randomized controlled trials were included. Included studies evaluated exercise therapy, endovascular or open revascularization for the treatment of IC. Outcomes of interest (freedom from major adverse limb event, health-related quality of life, and walking distance) were compared in various subgroups (age, sex, diabetes, smoking status, anatomical location of disease, and optimal medical therapy).

RESULTS

Twenty-six studies reported the outcomes of interest for the evidence map. The general conclusions of the studies that reported freedom from major adverse limb events were that reintervention rates for endovascular therapy at ≥2 years were >20%, major amputation rates were often not reported, and, after endovascular therapy, the 1-month mortality was low (<2%). Quality of life and walking distance data were sparse, limited to only endovascular intervention, and insufficient to make any strong conclusions.

CONCLUSIONS

IC in patients with peripheral arterial disease poses a significant socioeconomic and health care burden. Major, consequential gaps exist in the IC literature with respect to the assessment of patient reported outcome measures, standardized measures of walking distance and the comparative effectiveness of initial exercise therapy vs invasive intervention. The evidence gaps identified by the Society for Vascular Surgery appropriate use criteria on IC systematic review serve as a guide for future research efforts to optimize care for this patient population.

Patients with Acute Limb Ischemia Might Benefit from Endovascular Therapy-A 17-Year Retrospective Single-Center Series of 985 Patients

Acute lower limb ischemia (ALI) is a common vascular emergency, requiring urgent revascularization by open or endovascular means. The aim of this retrospective study was to evaluate patient demographics, treatment and periprocedural variables affecting the outcome in ALI patients in a consecutive cohort in a tertiary referral center. Primary outcome events (POE) were 30-day (safety) and 180-day (efficacy) combined mortality and major amputation rates, respectively. Secondary outcomes were perioperative medical and surgical leg-related complications and the 5-year combined mortality and major amputation rate. Statistical analysis used descriptive and uni- and multivariable Cox regression analysis. In 985 patients (71 ± 9 years, 56% men) from 2004 to 2020, the 30-day and 180-day combined mortality and major amputation rates were 15% and 27%. Upon multivariable analysis, older age (30 d: aHR 1.17; 180 d: 1.27) and advanced Rutherford ischemia stage significantly worsened the safety and efficacy POE (30 d: TASC IIa aHR 3.29, TASC IIb aHR 3.93, TASC III aHR 7.79; 180 d: TASC IIa aHR 1.97, TASC IIb aHR 2.43, TASC III aHR 4.2), while endovascular treatment was associated with significant improved POE after 30 days (aHR 0.35) and 180 days (aHR 0.39), respectively. Looking at five consecutive patient quintiles, a significant increase in endovascular procedures especially in the last quintile could be observed (17.5% to 39.5%, p < 0.001). Simultaneously, the re-occlusion rate as well as the number of patients with any previous revascularization increased. In conclusion, despite a slightly increasing early re-occlusion rate, endovascular treatment might, if possible, be favorable in ALI treatment.

A Meta-Analysis to Derive Population-Based Quality Benchmarks of the Incidence of Surgical Site Infection After Lower Limb Revascularization Surgery

OBJECTIVES

The reported incidence of surgical site infection (SSI) after lower limb revascularization surgery varies. We conducted a systematic review and meta-analysis of population-based studies reporting the incidence of SSI in adults who underwent these surgeries in high-income countries to derive SSI quality benchmarks.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and Evidence-Based Medicine Reviews (inception-to-April 28th, 2022) for population-based studies estimating the cumulative incidence of SSI among adults who underwent lower limb revascularization surgery for peripheral artery disease (PAD) in high-income countries. Two investigators independently screened abstracts and full-text articles, extracted data, and assessed risks of bias. We used random-effects models to pool data and GRADE to assess certainty.

RESULTS

Among 6258 citations, we included 53 studies (n=757,726 patients); eight of which (n=435,769 patients) reported non-overlapping data that were meta-analyzed. The pooled cumulative incidence of any SSI was 6.0 in 100 patients [95% confidence interval (CI)=4.3-8.0 in 100 patients; n=8 studies; n=435,769 patients; moderate certainty]. The cumulative incidence of Szilagyi grade I (cellulitis), grade II (subcutaneous tissue), and grade III (prosthetic graft) SSI was 6.5 in 100 patients (95% CI=4.3-8.6 in 100 patients; n=2 studies; n=39,645 patients; low certainty), 2.1 in 100 patients (95% CI=2.0-2.3 in 100 patients; n=2 studies; low certainty), and 0.4 in 100 patients (95% CI=0.4-0.4 in 100 patients; n=1 study; n=333,275 patients; low certainty), respectively. The pooled cumulative incidence of any early (in-hospital/≤30-days) and late (>30-days) SSI was 6.2 in 100 patients (95% CI=4.4 to 8.0 in 100 patients; n=7 studies; n=431,273 patients; moderate certainty) and 3.7 in 100 patients (95% CI=2.2-5.2 in 100 patients; n=2 studies; n=10,565 patients; low certainty), respectively.

CONCLUSIONS

This systematic review derived population-based benchmarks of the incidence of any SSI; Szilagyi I, II, and III SSI; and early and late SSI after lower limb revascularization surgery. These may be used by practicing surgeons and healthcare leaders/administrators to guide quality improvement efforts in the United States and perhaps other countries.

The adverse impact of pre-operative anaemia on survival following major lower limb amputation

INTRODUCTION

Approximately 5000 major lower-limb amputations (MLLA) for PAD occur per-annum in the UK with clinical outcomes being poor for this high-risk cohort of patients. Existing evidence suggests that anaemic surgical patients have an increased 30-day mortality, but this has not been explored in the context of MLLA. Recent prioritization processes suggested that MLLAs are a target area for research into outcome improvement. This cohort study evaluates the impact of anaemia on the outcome of MLLA to understand if optimization might improve outcomes.

METHODS

All PAD patients undergoing MLLA during 2015-2018 at a tertiary vascular centre were reviewed. Patients were stratified into groups; non-anaemia (>12 g/dL), mild-anaemia (12-10 g/dL) and severe-anaemia (<10 g/dL) by pre-operative haemoglobin (Hb). Primary outcome was overall survival by Kaplan-Meier. Secondary outcomes included length of stay (LOS), post-operative blood-transfusion, surgical-site infection (SSI) and myocardial infarction (MI). Cox-proportional-hazard and receiver-operator characteristics (ROC) analyses were conducted.

RESULTS

345 patients were followed up over (mean) 23 months. 105 were non-anaemic, 111 mildly anaemic and 129 severely anaemic. Patients with severe-anaemia had a higher incidence of heart and renal failure (p = 0.003) than those with non- or mild-anaemia. Overall survival worsened significantly with increasing anaemia (p = 0.001). LOS was significantly longer in mild-anaemia which is 26 (16-43) days, (p = 0.006) and severe-anaemia of 28 days (17-40), (p < 0.001) compared to non-anaemia of 18 (10-30) days. Post-operative blood-transfusion (RBC) was required more frequently in 70.5% of severely anaemic patients (p < 0.001), compared to mildly anaemic (24.3%) and non-anaemic (7.6%) patients, with those receiving RBCs having a significantly worse survival. There was no difference in MI, SSI or wound dehiscence. Anaemia was significantly associated with mortality; (HR 1.7 (1.04-2.78), p = 0.03). A minimum-Hb of 10.4 g/L (by ROC) was identified as a cutoff Hb for an increased risk of mortality.

CONCLUSION

Pre-operative anaemia is associated with worse outcome following MLLA, with increasing severity of anaemia associated with increasing mortality and RBC transfusion being potentially detrimental. More work is required to prospectively evaluate this relationship in this complex and multi-morbid cohort of patients.

Red blood cell distribution width as a predictor of cardiovascular outcomes in extensive aortoiliac disease

BACKGROUND

Aortoiliac peripheral artery disease may lead to disabling lower limb claudication or to lower limb chronic threatening ischemia, which is associated with increased short and long-term morbi-mortality. The red blood cell distribution width-coefficient of variation (RDW-CV) has been able to predict outcomes in other atherosclerotic diseases, such as myocardial infarction and stroke. The main objective of this study was to assess the predictive ability of perioperative RDW-CV in accurately predicting short and long-term major adverse cardiovascular events (MACE) and all-cause mortality in patients submitted to aortoiliac revascularization due to extensive aortoiliac atherosclerotic disease.

METHODS

From 2013 to 2020, patients who underwent aortoiliac revascularization due to severe aortoiliac disease were included in a prospective cohort. Blood samples were taken preoperatively and the patient's demographics, comorbidities, and postoperative outcomes were assessed. A multivariate Cox regression model was used to adjust for confounding and assess the independent effect of these prognostic factors on the outcomes.

RESULTS

The study group included 107 patients. Median follow-up was 57 (95% CI: 34.4-69.6) months. Preoperative RDW-CV was increased in thirty-eight patients (35.5%). Increased RDW-CV was associated with congestive heart failure - adjusted odds ratio of 5.043 (95% CI: 1.436-17.717, P=0.012). It could predict long-term occurrence of MACE (adjusted hazard ratio [aHR] 1.065, 95% CI: 1.014-1.118, P=0.011), all-cause mortality (aHR=1.069, 95% CI: 1.014-1.126, P=0.013), acute heart failure (AHF) (aHR=1.569, 95% CI: 1.179-2.088, P=0.002), and stroke (aHR=1.343, 95% CI: 1.044-1.727, P=0.022).

CONCLUSIONS

RDW is a widely available and low-cost marker that was able to independently predict long-term AHF, stroke, MACE, and all-cause mortality in patients with extensive aortoiliac disease submitted to revascularization. This biomarker could help assess which patients would likely benefit from stricter follow-up in the long-term.

Urinary Cystatin C Has Prognostic Value in Peripheral Artery Disease

Despite its association with adverse outcomes, peripheral artery disease (PAD) remains undertreated. Cystatin C is elevated in patients with renal disease and may be a marker of cardiovascular disease. We examined the prognostic ability of urinary Cystatin C (uCystatinC) in predicting adverse PAD-related events. In this prospective case-control study, urine samples were collected from patients with PAD (n = 121) and without PAD (n = 77). The cohort was followed for 2 years. uCystatinC was normalized to urinary creatinine (uCr) (uCystatinC/uCr; μg/g). The primary outcome was major adverse limb event (MALE; composite of vascular intervention (open or endovascular) or major limb amputation). The secondary outcome was worsening PAD status (drop in ABI ≥ 0.15). Multivariable Cox regression and Kaplan–Meier analyses were performed to assess the prognostic value of uCystatinC/uCr with regards to predicting MALE and worsening PAD status. Our analysis demonstrated that patients with PAD had significantly higher median [IQR] uCystatinC/uCr levels (24.9 μg/g [14.2–32.9] vs. 20.9 μg/g [11.1–27.8], p = 0.018). Worsening PAD status and MALE were observed in 39 (20%) and 34 (17%) patients, respectively. uCystatinC/uCr predicted worsening PAD status with a hazard ratio (HR) of 1.78 (95% CI 1.12–2.83, p = 0.015), which persisted after controlling for baseline demographic and clinical characteristics (adjusted HR 1.79 [95% CI 1.11–2.87], p = 0.017). Patients with high uCystatinC/uCr had a lower 2-year freedom from MALE (77% vs. 89%, p = 0.025) and worsening PAD status (63% vs. 87%, p = 0.001). Based on these data, higher uCystatinC/uCr levels are associated with adverse PAD-related events and have prognostic value in risk-stratifying individuals for further diagnostic vascular evaluation or aggressive medical management.

Major adverse limb events in patients with femoro-popliteal and below-the-knee peripheral arterial disease treated with either sirolimus-coated balloon or standard uncoated balloon angioplasty: a structured protocol summary of the "SirPAD" randomized controlled trial

BACKGROUND

Peripheral arterial disease is a progressive atherosclerotic disease with symptoms ranging from an intermittent claudication to acute critical limb ischemia and amputations. Drug-coated balloons and stents were developed to prevent neo-intimal proliferation and restenosis after percutaneous transluminal angioplasty. Randomized controlled trials showed that drug-coated, notably paclitaxel-coated, devices reduce restenosis, late lumen loss, and the need for target lesion re-vascularization compared with uncoated ones. However, the size of these trials was too small to prove superiority for "hard" clinical outcomes. Moreover, available studies were characterized by too restrictive eligibility criteria. Finally, it remains unclear whether paclitaxel-coated balloons may impair long-term survival. Alternative drug-coated balloons, the so-called limus-based analogs, have been approved for clinical use in patients with peripheral arterial disease. By encapsulating sirolimus in phospholipid drug nanocarriers, they optimize adhesion properties of sirolimus and provide better bioavailability.

METHODS

In this investigator-initiated all-comer open-label phase III randomized controlled trial, we will evaluate whether sirolimus-coated balloon angioplasty is non-inferior and eventually superior, according to a predefined hierarchical analysis, to uncoated balloon angioplasty in adults with infra-inguinal peripheral arterial disease requiring endovascular angioplasty. Key exclusion criteria are pregnancy or breastfeeding, known intolerance or allergy to sirolimus, and participation in a clinical trial during the previous 3 months. The primary efficacy outcome is the composite of two clinically relevant non-subjective "hard" outcomes: unplanned major amputation of the target limb and endovascular or surgical target lesion re-vascularization for critical limb ischemia occurring within 1 year of randomization. The primary safety outcome includes death from all causes.

DISCUSSION

By focusing on clinically relevant outcomes, this study will provide useful information on the efficacy and safety of sirolimus-coated balloon catheters for infra-inguinal peripheral arterial disease in a representative ("all-comer") population of unselected patients. As regulatory agencies had raised safety concerns in patients exposed to paclitaxel-coated devices (versus uncoated ones), collect mortality data up to 5 years after randomization will be collected.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04238546.

Outcomes of Axillofemoral Bypass for Intermittent Claudication

OBJECTIVE

While endovascular therapy is often first-line treatment for medically refractory intermittent claudication (IC) caused by aorto-femoral disease, suprainguinal bypass is commonly performed. Although this is often aorto-femoral bypass (AoFB), axillo-femoral bypass (AxFB) is still sometimes performed despite limited data evaluating its utility in the management of IC. Our goal was to assess the safety and durability of AxFB performed for IC.

METHODS

The Vascular Quality Initiative (2009-2019) was queried for suprainguinal bypass performed for IC. Univariable and multivariable analyses were used to compare perioperative and one-year outcomes between AxFB and a comparison cohort of AoFB.

RESULTS

We identified 3,261 suprainguinal bypasses performed for IC: 436 AxFB and 2,825 AoFB. Overall, mean age was 61.4 ± 9.1 years, 58.8% of patients were male sex, and 59.7% currently smoked. Patients undergoing AxFB, compared with AoFB, were more often older, male, never-smokers, and ambulated with assistance (all P<.001). They more often had hypertension, diabetes, coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease, end-stage renal disease, previous outflow peripheral endovascular interventions, and previous inflow or outflow bypass. AxFB, compared with AoFB, were more often uni-femoral (all P<.05). Patients undergoing AxFB, compared with AoFB, had shorter postoperative length of stay (median 4 vs. 6 days) and fewer perioperative pulmonary (3% vs. 7.9%) and renal complications (5.5% vs. 9.9%), but more perioperative ipsilateral major amputations (.9% vs. 0.04%) (all P<.05). There were no significant differences in perioperative myocardial infarction (2.8% vs. 2.7%), stroke (.7% vs. 1.1%), and death (1.8% vs. 1.7%) rates, respectively. At one year, Kaplan-Meier analysis demonstrated that the AxFB, compared with AoFB cohort, exhibited higher rates of death (7.3% vs. 3.6%, P=.002); graft occlusion or death (14.3% vs. 7.2%, P=.001); ipsilateral major amputation or death (12.5% vs. 5.6%, P<.001); and reintervention, amputation, or death (19% vs. 8.6%, P<.001). On multivariable analysis, AxFB was independently associated with increased risk of one-year reintervention, amputation, or death (HR 1.6, 95% CI 1.03-2.4, P=.04).

CONCLUSIONS

This retrospective analysis suggests that long-term complications were more frequent in patients who underwent AxFB as compared to AoFB, although patients treated with AxFB were at higher risk with more comorbidities. Since AxFB is associated with significant perioperative morbidity, mortality, and long-term complications, serious consideration should be given prior to its use for IC.

Critical appraisal of evidence on bypass surgery versus endovascular treatment for intermittent claudication: a systematic review and meta-analysis

INTRODUCTION

Intermittent claudication (IC) stage of peripheral artery disease (PAD) is associated with significant impairment of quality of life. In the subset of patients with disabling IC refractory to best medical treatment (BMT), revascularization procedures may be considered. However, evidence comparing open revascularization surgery, endovascular treatment and BMT focussing on the impact on quality of life is very sparse. We aim to review clinical, anatomical and hemodynamic outcomes after bypass surgery compared to BMT and/or endovascular treatment in IC patients.

EVIDENCE ACQUISITION

We systematically reviewed controlled trials and comparative cohort studies assessing quality of life, walking performance, clinical/symptomatic improvement, symptom recurrence, patency rates, ankle-brachial index (ABI) improvement and adverse events after bypass surgery versus endovascular treatment/BMT in IC patients.

EVIDENCE SYNTHESIS

Eleven studies involving 16,608 patients were included. Compared to BMT, bypass surgery was associated with a significantly greater improvement on Short-Form 36 (SF-36) physical functioning score (mean difference (MD), -14.0; 95% confidence interval (CI), -21.2 to -6.8), Walking Impairment Questionnaire (WIQ) walking distance score (MD, -0.23; 95% CI, -0.29 to -0.16) and SF-36 bodily pain score (MD, -13.0; 95% CI, -20.2 to -5.8). There were no significant differences between bypass and endovascular treatment regarding the three scores. Bypass surgery presented better primary patency rates at 1 (odds ratio (OR), 0.47; 95% CI, 0.29 to 0.76) and 5 years (OR, 0.44; 95% CI, 0.34 to 0.57) and better ABI improvement (MD, -0.07; 95% CI, -0.12 to -0.03) when compared to endovascular treatment. There were no statistically significant differences between bypass and endovascular patients regarding secondary patency rates, 30-day mortality and major amputation.

CONCLUSIONS

Lower limb revascularization may be beneficial in patients with disabling and refractory IC when the primary goal is to improve quality of life and walking capacity. Bypass surgery is associated to better symptomatic status, long-term primary patency and ABI improvement when compared to endovascular surgery, especially in anatomically extensive disease. Further studies addressing patient-reported outcomes and including a BMT group are paramount for more robust evidence on IC treatment and, consequently, better decision making.

Outcome Analysis Using the Modified Frailty Index-5 in Patients With Complex Aortoiliac Disease

OBJECTIVES

Vascular surgery patients commonly have several comorbidities that cumulatively lead to a frailty status. The cumulative comorbidities disproportionately increase the risk of adverse events and are also associated with worsened long-term prognosis. In recent years, several tools have been elaborated with the objective of quantifying a patient's frailty. One of them is the modified frailty index-5 (mFI-5), a simplified and easy to use index. There is scarce data regarding its value as a prognostic factor in aortoiliac occlusive disease. The aim of this work is to validate mFI-5 as a potential postoperative prognostic indicator in this population.

METHODS

From January 2013 to January 2020, 109 patients who underwent elective revascularizations, either endovascular or open surgery, having Trans-Atlantic Inter-Society Consensus II type D aortoiliac lesions in a tertiary and a regional hospital were selected from a prospective vascular registry. Demographic data was collected including diabetes mellitus, chronic heart failure, chronic obstructive pulmonary disease, arterial hypertension requiring medication and functional status. The 30-d and subsequent long-term surveillance outcomes were also collected including major adverse cardiovascular events (MACE), major adverse limb events (MALE) and all-cause mortality were assessed in the 30-d post-procedure and in the subsequent long-term surveillance period. The mFI-5 was applied to this population to evaluate the prognostic impact of this frailty marker on mortality and morbidity.

RESULTS

In the long-term follow-up, mFI-5 was significantly associated with MACE (hazard ratio [HR] 2.469; 95% confidence interval [CI]: 1.267-4.811; P = .008) and all-cause mortality (HR 2.585; 95% CI: 1.270-5.260; P = .009). However, there was no significant association with 30-day outcomes. Along with the presence of chronic kidney disease, mFI-5 was the prognostic factor better able of predicting MACE. No prognostic value was found regarding short-term outcomes.

CONCLUSION

The mFI-5 index may have a role in predicting long term outcomes, namely MACE and all-cause mortality, in the subset of patients with extensive aortoiliac occlusive disease. Its ease of use can foster its application in risk stratification and contribute for the decision-making process.

The Impact of Lower Extremity Skeletal Muscle Atrophy and Myosteatosis on Revascularization Outcomes in Patients with Peripheral Arterial Disease

Background: This study investigated whether lower extremity muscle atrophy and myosteatosis in patients with peripheral arterial disease (PAD) are correlated to postoperative outcomes, such as reintervention or amputation-free survival. Methods: In this single-center retrospective cohort study of 462 patients treated for peripheral arterial disease scheduled for intervention, muscle mass and the presence of fattening of the lower extremity muscles were measured semiautomatically in a single computed tomography slice of the treated leg. Binary logistic regression models and Cox proportional hazards models were used to determine the effect of muscle atrophy and myosteatosis on reintervention and amputation. Results: Muscle atrophy and myosteatosis increased in PAD patients with Fontaine class IV compared with Fontaine class IIa. In PAD patients with muscle atrophy or myosteatosis, no association was found with the reintervention rate or reintervention-free survival, but an association was found with amputation-free survival, even after adjustment for patient-related, disease-severity, and comorbidities-related factors. Conclusion: Muscle atrophy and mysosteatosis increased in PAD patients with increasing disease severity. Lower extremity muscle atrophy and myosteatosis are associated with amputation rate and amputation-free survival in PAD patients. No association with reintervention rate or reintervention-free survival was found. Muscle atrophy and myosteatosis may serve as additional risk factors in decision making in the often frail vascular patient.

Outcomes of Lower Extremity Endovascular Revascularization: Potential Predictors and Prevention Strategies

Peripheral artery disease (PAD) is a manifestation of atherosclerosis, which may affect arteries of the lower extremities. The most dangerous PAD complication is chronic limb-threatening ischemia (CLTI). Without revascularization, CLTI often causes limb loss. However, neither open surgical revascularization nor endovascular treatment (EVT) ensure long-term success and freedom from restenosis and revascularization failure. In recent years, EVT has gained growing acceptance among all vascular specialties, becoming the primary approach of revascularization in patients with CLTI. In clinical practice, different clinical outcomes after EVT in patients with similar comorbidities undergoing the same procedure (in terms of revascularization technique and localization of the disease) cause unsolved issues that need to be addressed. Nowadays, risk management of revascularization failure is one of the major challenges in the vascular field. The aim of this literature review is to identify potential predictors for lower extremity endovascular revascularization outcomes and possible prevention strategies.

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.

Antithrombotic therapy for postinterventional management of peripheral arterial disease

PURPOSE

Evidence on the use of antithrombotic pharmacotherapy in patients undergoing revascularization of lower extremities for symptomatic peripheral arterial disease (PAD) is reviewed.

SUMMARY

Individuals with PAD can experience leg pain, intermittent claudication, critical limb ischemia, and acute limb ischemia. In such patients, revascularization may be indicated to improve the quality of life and to prevent amputations. Antithrombotic therapy is often intensified in the postrevascularization period to prevent restenosis of the index artery and to counteract the prothrombotic state induced by the intervention. Therapeutic modalities include dual antiplatelet therapy (DAPT), anticoagulation, a combination of antiplatelet and anticoagulation therapy, and addition of cilostazol to single antiplatelet therapy. Subgroup analyses of data from randomized clinical trials provided low-quality evidence for the use of DAPT in patients with a below-knee prosthetic bypass graft and anticoagulation for those with a venous bypass graft. Cilostazol, when added to aspirin therapy, has been shown to prevent index vessel reocclusion after an endovascular intervention in patients at low risk for thrombosis in several small randomized trials.

CONCLUSION

There is a considerable paucity of high-quality evidence on the optimal antithrombotic regimen for patients undergoing lower extremity revascularization, with no particular therapy shown to consistently improve patient outcomes. The decision to initiate intensified antithrombotic therapy should include a close examination of its risk-benefit profile. The demonstrated benefit of such treatment is restricted to the prevention of index artery reocclusion, while an increased risk of bleeding may lead to significant morbidity and mortality.

Tibial bypass in patients with intermittent claudication is associated with poor outcomes

OBJECTIVE

Given that intermittent claudication (IC) rarely progresses to chronic limb-threatening ischemia and limb loss, safety and durability of elective interventions for IC are essential. Whether patients with IC benefit from tibial intervention is controversial, and data supporting its utility are limited. Despite endovascular therapy expansion, surgical bypass is still commonly performed. We sought to assess outcomes of bypass to tibial arteries for IC.

METHODS

The Vascular Quality Initiative (2003-2018) was queried for infrainguinal bypasses performed for IC. Perioperative and 1-year outcomes were compared between bypasses constructed to tibial and popliteal arteries.

RESULTS

Of 5347 infrainguinal bypasses, 1173 (22%) and 4184 (78%) were tibial and popliteal bypasses, respectively. Overall, mean age was 65 ± 10 years, and patients were often men (72%) and current smokers (42%). Tibial bypasses commonly targeted posterior tibial (40%), tibioperoneal trunk (23%), and anterior tibial (19%) arteries. Great saphenous vein was more often used for tibial bypass than for popliteal bypass (78% vs 54%; P < .001). Patients undergoing tibial compared with popliteal bypass more often had impaired ambulation and prior ipsilateral bypasses and were less often taking antiplatelets and statins (all P < .05). In the perioperative period, tibial bypass patients had longer postoperative length of stay (4.5 ± 3.5 vs 3.5 ± 2.8 days), more pulmonary complications (1.3% vs 0.6%), and higher return to the operating room (7% vs 4%; all P < .05). Perioperative myocardial infarction (1.2% vs 0.8%; P = .19), stroke (0.4% vs 0.4%; P = .91), and mortality (0.3 vs 0.3%; P = .86) rates were similar between the cohorts. At 1 year, tibial compared with popliteal bypasses exhibited lower freedom from occlusion/death (81% vs 89%; P < .001), ipsilateral major amputation/death (90% vs 94%; P < .001), and reintervention/amputation/death (73% vs 80%; P < .001), but patient survival was similar (96% vs 97%; P = .07). On multivariable analysis, tibial compared with popliteal bypass was independently associated with increased occlusion/death (hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.28-2.11; P < .001), major ipsilateral amputation/death (HR, 1.6; 95% CI, 1.12-2.19; P = .003), and ipsilateral reintervention/amputation/death (HR, 1.51; 95% CI, 1.28-1.79; P < .001), with similar patient survival.

CONCLUSIONS

In patients with IC, tibial bypass was associated with poor outcomes, including major amputation. Surgeons should exhaust nonoperative therapies and present realistic outcome expectations to their patients before offering such intervention.

Myocardial injury after aortoiliac revascularization for extensive disease: A survival analysis

BACKGROUND

This study aims to evaluate the incidence of myocardial injury after non-cardiac surgery for an extensive disease pattern (TASC II type D) and to examine its prognostic value.

METHODS

This prospective study included a total of 66 consecutive patients (62 males, 4 females; mean age 62.5±8.2 years) who underwent elective revascularization for aortoiliac TASC II type D lesions in the tertiary setting between January 2013 and March 2019. The patients were scheduled for revascularization either by open surgery or endovascular approach. Cardiac troponins were routinely measured in the postoperative period. Myocardial injury after non-cardiac surgery was defined as the elevation of cardiac troponin for at least one value above the 99th percentile upper reference limit. Myocardial infarction, acute heart failure, stroke, major adverse cardiovascular events, major adverse limb events, and all-cause mortality were assessed both postoperatively and during follow-up.

RESULTS

The incidence of myocardial injury after non-cardiac surgery was 25.8%. In the multivariate analysis, chronic heart failure was found to be a significant risk factor for myocardial injury after non-cardiac surgery (odds ratio: 10.3; 95% confidence interval 1.00-106.8, p=0.018). At 12 months after revascularization, the diagnosis of myocardial injury after non-cardiac surgery was significantly associated with myocardial infarction, stroke, major adverse cardiovascular events, major adverse limb events, and all-cause mortality. At 12 months after revascularization, the diagnosis of myocardial injury after non-cardiac surgery was significantly associated with myocardial infarction (log-rank p=0.002), stroke (log-rank p=0.007), major adverse cardiovascular events (log-rank p=0.000), major adverse limb events (log-rank p=0.007), and all-causemortality (log-rank p=0.000).

CONCLUSION

Our study results suggest that myocardial injury after non-cardiac surgery plays a role as a predictor of significant cardiovascular comorbidities and mortality after complex aortoiliac revascularization. The presence of chronic heart failure is also associated with a higher incidence of myocardial injury after aortoiliac TASC II type D revascularization. Therefore, preemptive strategies should be adopted to identify and treat these patients.

Endovascular Therapy in an "All-Comers" Risk Group for Chronic Limb-Threatening Ischemia Demonstrates Safety and Efficacy When Compared with the Established Performance Criteria Proposed by the Society for Vascular Surgery

BACKGROUND

The aim of this study was to describe the applicability of the Society for Vascular Surgery (SVS) objective performance goals (OPGs) as a tool to evaluate results in the context of endovascular management of noncomplex and complex patients (i.e., end stage renal disease/history of prosthetic conduit) with chronic limb-threatening ischemia (CLTI).

METHODS

Patients diagnosed with CLTI undergoing endovascular procedures from March 2016 to April 2017 were included, and medical records were examined. Patients were categorized as OPG risk (OPGR) and non-OPG risk (nOPGR) groups in accordance with the SVS performance criteria. We compared clinical events between the two groups and then further to the SVS OPGs. Thirty-day outcomes (safety) were major amputation (AMP), major adverse limb events (MALEs), and major adverse cardiovascular events (MACEs), and 1-year outcomes (efficacy) were limb salvage, MALE + 30-day perioperative death (MALE + POD), and survival. Mortality was demonstrated using Kaplan-Meier analysis.

RESULTS

A total of 72 patients were included (OPGR = 58.3% vs. nOPGR = 41.7%). Mean follow-up was 20 months (range, 1-40 months). Retrograde pedal access was used in 65.2% of patients. The overall AMP rate was 2.7% (OPGR = 4.7%, nOPGR = 0%, P = 0.225, vs. SVS OPG<3%), MALE was 4.1% (OPGR = 7.1%, nOPGR = 0%, P = 0.135, vs. SVS OPG<8%), and MACE was 6.9% (OPGR = 2.3%, nOPGR = 13.3%, P = 0.071, vs. SVS OPG<8%). The limb salvage was 90.3% (OPGR = 88%, nOPGR = 93.3%, P = 0.46, vs. SVS OPG>84%), MALE + POD was 76.4% (OPGR = 78.6%, nOPGR = 73.4%, P = 0.606, vs. SVS OPG>71%), and survival was 77.7% (OPGR = 83.3%, nOPGR = 70%, P = 0.18, vs. SVS OPG>80%).

CONCLUSIONS

The SVS OPGs set appropriate safety and efficacy standards as a bar for new technologies. In this series, endovascular therapy in all-comers exceeded the safety and efficacy endpoints proposed by the limited risk OPG panel.

Protocol for a prospective observational diagnostic study: intraoperative simultaneous limb pressure monitoring (INSTANT) study

INTRODUCTION

Peripheral vascular disease (PVD) is a condition caused by arterial blockages causing inadequate blood flow, resulting in pain and gangrene of the legs. Endovascular therapy, such as angioplasty, can be used to treat PVD, however, the operator feedback during surgery is primarily anatomic based on the angiogram. Because physiologic blood perfusion can be difficult to determine based on anatomic images, we propose introducing physiological measurements into the operating room. This study will investigate whether the change in intraoperative monitoring of haemodynamic measurements such as the Toe-Brachial Index during endovascular surgery for lower extremity atherosclerotic PVD is associated with clinical outcomes such as major adverse limb events (MALEs).

METHODS AND ANALYSIS

This study will be a prospective, operator-blinded and blinded endpoint adjudicated observational diagnostic cohort study. A total of 80 legs will be enrolled in the study. Ankle and toe blood pressures will be measured non-invasively at predetermined time points before, during and after surgery, and we will assess associations between changes in intraoperative pressure measurements and postoperative clinical and haemodynamic outcomes. The primary outcome will be MALE within 1 year, and secondary outcomes include follow-up pressure measurements, vessel patency, reintervention, clinical staging improvement, amputation and death.

ETHICS AND DISSEMINATION

Regional hospital ethics approval has been granted (Ottawa Hospital Research Institute - Research Ethics Board, Protocol 20180656-01H). On completion of data analysis, the study will submitted for presentation at international vascular surgical society meetings, in addition to submission for publication in publicly accessible medical journals.

TRIAL REGISTRATION NUMBER

NCT03875846.