Cardiovascular and Limb Events Following Endovascular Revascularization Among Patients ≥65 Years Old: An American College of Cardiology PVI Registry Analysis

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.

Revascularization Outcomes Stratified by Glycemic Control in Patients with Diabetes Mellitus and Chronic Limb-Threatening Ischemia

BACKGROUND

The prevalence of chronic limb-threatening ischemia (CLTI) has increased alongside rising rates of diabetes mellitus (DM). While diabetic patients with CLTI have worse outcomes compared to patients without diabetes, conflicting data exist on the relationship between the severity of DM and CLTI outcomes. Close inspection of the relationship between DM severity and outcomes in CLTI may benefit surgical decision-making and patient education.

METHODS

We retrospectively reviewed patients who received endovascular intervention or surgical bypass for CLTI at our multidisciplinary Limb Preservation Program from 2013 to 2019 to collect patient characteristics using Society for Vascular Surgery (SVS) reporting standards, arterial lesion characteristics from recorded angiograms, and outcomes, including survival, amputation, wound healing, and revascularization patency. Controlled DM was defined as SVS Grade 1 (controlled, not requiring insulin) and Grade 2 (controlled, requiring insulin), while uncontrolled DM was defined as SVS Grade 3 (uncontrolled), and DM severity was assessed using preoperative hemoglobin A1c (HgbA1c) values. Product-limit Kaplan-Meier was used to estimate survival functions. Univariable Cox proportional hazards analyses guided variable selection for multivariable analyses.

RESULTS

Our Limb Preservation Program treated 177 limbs from 141 patients with DM. Patients with uncontrolled DM were younger (60.44 ± 10.67 vs. 65.93 ± 10.89 years old, P = 0.0009) and had higher HgbA1c values (8.97 ± 1.85% vs. 6.79 ± 1.10%, P < 0.0001). Fewer patients with uncontrolled DM were on dialysis compared to patients with controlled DM (15.6% vs. 30.9%, P = 0.0278). By Kaplan-Meier analysis, DM control did not affect time to mortality, limb salvage, wound healing, or loss of patency. However, multivariable proportional hazards analysis demonstrated increased risk of limb loss in patients with increasing HgbA1C (hazard ratio (HR) = 1.96 [1.42-2.80], P < 0.0001) or dialysis dependence (HR = 15.37 [3.44-68.73], P = 0.0003), increased risk of death in patients with worsening pulmonary status (HR = 1.70 [1.20-2.39], P = 0.0026), and increased risk of delayed wound healing in patients who are male (HR = 0.48 [0.29-0.79], P = 0.0495). No independent association existed between loss of patency with any of the variables we collected.

CONCLUSIONS

Patients with uncontrolled DM, as defined by SVS reporting standards, do not have worse outcomes following revascularization for CLTI compared to patients with controlled DM. However, increasing HgbA1c is associated with a greater risk for early amputation. Before revascularization, specific attention to the level of glycemic control in patients with DM is important, even if DM is "controlled." In addition to aggressive attempts at improved glycemic control, those with elevated HgbA1c should receive careful education regarding their increased risk of amputation despite revascularization. Future work is necessary to incorporate the severity of DM into risk models of revascularization for the CLTI population.

Failure-to-Salvage After Femoropopliteal Bypass Surgery is Associated With Nonmodifiable Risk Factors

INTRODUCTION

Bypass graft failure and major amputation are among the worst complications after femoropopliteal bypass surgery. In this large multicenter analysis, we examined our incidence and risk factors for failure-to-salvage (FTS) following either bypass surgery or bypass graft failure.

METHODS

A regional multicenter database was retrospectively queried for all femoropopliteal bypass procedures performed between 2002 and 2021. Re-do bypasses were excluded. The primary outcome was FTS, defined as major ipsilateral limb amputation within 90 d following index bypass surgery or bypass graft failure. Bypass graft failure was defined as critical stenosis or occlusion of the bypass graft requiring reintervention. Graft rescue was defined as bypass graft failure without subsequent major ipsilateral limb amputation within 90 d. Multivariable logistic regression analysis was utilized to identify factors associated with bypass graft failure and FTS.

RESULTS

Over the study period, 1315 femoropopliteal bypass procedures were performed across five hospitals. There were 25 major amputations within 90 d of initial bypass. Bypass graft failure was diagnosed in an additional 503 (38.3%) patients. Mean time to graft failure was 619 d. On multivariable analysis, bypass for tissue loss (adjusted odds ratio [aOR] 1.38 [95% confidence interval (CI) 1.03-1.83], P = 0.03) was associated with graft failure. Of patients with graft failure, 33 had major amputation, leading to an overall FTS incidence of 4.4% (n = 58) over a mean follow-up period of 3.4 y. Patient demographics, medical comorbidities, and bypass conduits were similar between the FTS and graft rescue groups (n = NS each). The FTS group more frequently underwent bypass for tissue loss (51.7% versus 29.8%, P = 0.002), and an infrageniculate bypass target was more frequently utilized in FTS compared to graft rescue patients (81.0% versus 60.4%, P = 0.002). Anticoagulation (34.5% in FTS versus 37.7% in rescue) and dual antiplatelet therapy (15.5% versus 22.1%, respectively) were similar between groups (P = NS each). On multivariable analysis, factors associated with FTS included infrageniculate target (aOR 2.42 [95% CI 1.22-4.08], P = 0.01), black race (aOR 2.47 [95% CI 1.04-5.84], P = 0.04), and bypass for tissue loss (aOR 4.75 [95% CI 1.41-16.0], P = 0.01). Anticoagulation and dual antiplatelet therapy were not associated with loss of graft patency or FTS.

CONCLUSIONS

Failure-to-salvage after femoropopliteal bypass surgery is associated with nonmodifiable factors, and may represent progression of underlying disease. These data may help inform vascular surgeons in counseling patients with failing bypass grafts. Further investigation of care delivery factors improving likelihood of graft salvage may be warranted.

Heparin-Bonded Expanded Polytetrafluoroethylene Is a Solution for Infrapopliteal Revascularization in the Absence of an Adequate Autologous Vein Graft

BACKGROUND

To analyze the outcomes of heparin-bonded expanded polytetrafluoroethylene (HePTFE) graft as an alternative conduit in infrapopliteal revascularization of chronic limb-threatening ischemia (CLTI) in the absence of an autologous vein conduit.

METHODS

A single-center retrospective analysis of patients with CLTI submitted to infrapopliteal bypasses with autologous vein graft (VEIN group) or HePTFE graft (HePTFE group) was implemented. Primary end points were freedom from CLTI at 12 months and recurrence of CLTI at 3 years. Secondary end points included freedom from major amputation, amputation-free survival (AFS), survival, and primary (PP) and secondary patency (SP) rates at 3 years of follow-up.

RESULTS

A total of 348 limbs submitted to infrapopliteal bypasses, 214 with venous graft and 134 with HePTFE graft, were followed-up for a median of 25 months. Most patients of the HePTFE group were male (69%), with a median age of 76 years (interquartile range [IQR] 15). Fifty-nine percent of the limbs of the HePTFE group had Wound grade ≥2, being 46% of them infected. Eighty-eight percent were GLASS stage III. Freedom from CLTI was not significantly different between HePTFE and VEIN groups (75% vs. 84%, adjusted hazard ratio [aHR] 0.88, confidence interval [CI] 0.66-1.18, P = 0.401). Recurrence of CLTI was higher in the HePTFE group (42% vs.18% at 3 years; aHR 2.82, CI 1.59-5.00, P < 0.001). The VEIN group achieved higher rates of freedom from major amputation (87% vs.69% at 3 years; aHR 2.21, CI 1.31-3.75, P = 0.003) and AFS (59% vs. 37% at 3 years; aHR 1.39, CI 1.02-1.88, P = 0.036), but no significance in survival (aHR 1.10, CI 0.72-1.66, P = 0.667). Patency rates were inferior in the HePTFE group, with 2-year PP and SP rates of 52% vs. 74%, and 76% vs. 90%, respectively (PP: aHR 1.70, CI 1.11-2.59, P = 0.014; SP: aHR 2.51, CI 1.42-4.42, P = 0.001).

CONCLUSIONS

Infrapopliteal bypass with autologous vein graft is the gold standard to treat CLTI limbs. HePTFE graft should be regarded as an alternative for complex infrapopliteal revascularization when lacking an autologous vein conduct.

Acupoint transplantation versus non-acupoint transplantation using autologous peripheral blood mononuclear cells in treating peripheral arterial disease

Numerous studies have discussed the therapeutic outcomes of using cell therapy or acupuncture to treat peripheral artery disease (PAD). However, there are no long-term studies on the safety and efficacy of transplanting peripheral blood mononuclear cells (PBMNCs) via acupoints to treat PAD. We first reviewed the short-term and long-term clinical results of PAD patients treated with PBMNCs through intramuscular non-acupoint transplantation (control group; n = 45) or intramuscular acupoint transplantation (acupoint group; n = 45) at a single university hospital general medical center between December 2002 and September 2022. Pain intensity (assessed with the verbal rating scale [VRS] score) in the acupoint group was considerably lower than that in the control group at month 1 (mean ± standard deviation [SD]: 1.29 ± 0.96 vs 1.76 ± 0.82; P = 0.016) and month 3 (mean ± SD: 1.27 ± 0.90 vs 1.61 ± 0.86; P = 0.042). We observed significant improvement of VRS score (P < .001 for all) and ankle-brachial index (ABI; P < .001 for all) from baseline in both groups at months 1, 3, 6, 12, 36, and 60. The 10-year cumulative rate of major amputation-free survival (MAFS) was higher in the acupoint group as compared to the control group (81.9%, 95% confidence interval [CI]: 71.3%-94.1% vs 78.5%, 95% CI: 66.7%-92.3%; P = 0.768). Compared with the routine injection method, intramuscular transplantation of PBMNCs via selected acupoints could significantly decrease the short-term pain intensity in patients with PAD, which remains an option for consideration.

Longitudinal outcomes following peripheral vascular intervention among older persons living with HIV

BACKGROUND

Persons living with human immunodeficiency virus (HIV, PLWH) have an increased risk of peripheral artery disease (PAD) in comparison to the general population. However, a gap remains in understanding optimal management for this condition. This study assesses longitudinal outcomes associated with peripheral endovascular intervention (PVI) for PAD among PLWH.

METHODS

All Medicare fee-for-service patients undergoing femoropopliteal artery PVI between April 1, 2015 and December 31, 2018 were identified and stratified by HIV serostatus. The primary outcome was major adverse limb events (MALE), defined as major amputation or arterial embolism/thrombosis following an index procedure. The subdistribution hazard was used to evaluate the association between HIV serostatus and MALE, accounting for the competing risk of death. Results were adjusted for sociodemographics and major comorbidities.

RESULTS

Of 168,553 patients who underwent PVI, 357 (0.21%) were PLWH. The average age was 77.0 ± 7.6 years; 80.3% had hypertension, 70.3% had hyperlipidemia, and 24.6% had tobacco use disorder. Compared to those without HIV, PLWH were younger and had a higher burden of cardiovascular risk factors. MALE were substantially more frequent among PLWH, with a cumulative incidence of 24.6%, compared to 14.5% among those without HIV. The adjusted subdistribution hazard ratio was 1.26 (95% CI 1.00-1.58, p = 0.05). The use of guideline-directed statin therapy was low in both groups in the 90 days following revascularization (57.9% in PLWH vs 58.1% in those without HIV, p = 0.95).

CONCLUSION

Among US Medicare beneficiaries, PLWH had poorer long-term outcomes following PVI. Greater attention to the management of symptomatic PAD is warranted for the HIV population, particularly following revascularization.

The natural history of chronic limb-threatening ischemia after technical failure of endovascular intervention

OBJECTIVES

The treatment for chronic limb-threatening ischemia (CLTI) has changed dramatically in the last few decades with a shift toward an endovascular-first approach and aggressive revascularization to achieve limb salvage. As the size of the CLTI population and intervention rates increase, patients will continue to experience technical failure (TF). Here, we describe the natural history of patients after TF of endovascular intervention for CLTI.

METHODS

We conducted a retrospective cohort study of patients with CLTI who attempted endovascular intervention or bypass at our multidisciplinary limb salvage center from 2013 to 2019. Patient characteristics were collected according to the Society for Vascular Surgery's reporting standards. Primary outcomes included survival, limb salvage, wound healing, and revascularization patency. Product-limit Kaplan-Meier estimated survival functions for these outcomes, and between-group comparisons were made using Mantel-Cox log-rank nonparametric tests.

RESULTS

We identified 242 limbs from 220 unique patients who underwent primary bypass (n = 30) or attempted endovascular intervention (n = 212) at our limb salvage center. Endovascular intervention was a TF in 31 (14.6%) limbs. After TF, 13 limbs underwent secondary bypass and 18 limbs were managed medically. Patients who experienced TF tended to be older (P < .001), male (P = .003), current tobacco users (P = .014), have longer lesions (P = .001), and have chronic total occlusions of target arteries (P < .001) as compared with those who experienced technical success. Furthermore, the TF group had worse limb salvage (P = .047) and slower wound healing (P = .028), but their survival was not different. Survival, limb salvage, and wound healing were not different in patients who received secondary bypass or medical management after TF. The secondary bypass group was older (P = .012) and had a lower prevalence of tibial disease (P = .049) than the primary bypass group and trended toward decreased survival, limb salvage, and wound healing (P = .059, P = .083, and P = .051, respectively).

CONCLUSIONS

Increased age, male sex, current tobacco use, longer arterial lesions, and occluded target arteries are associated with TF of endovascular intervention. Limb salvage and wound healing are relatively poor after TF of endovascular intervention, but survival appears comparable with patients who experience technical success. Secondary bypass may not always rescue patients after TF, though our sample size limits statistical power. Interestingly, patients who received a secondary bypass after TF trended toward decreased survival, limb salvage, and wound healing compared with primary bypass.

Chronic Limb-Threatening Ischemia and the Need for Revascularization

BACKGROUND

Patients presenting with critical limb-threatening ischemia (CLTI) have been increasing in number over the years. They represent a high-risk population, especially in terms of major amputation and mortality. Despite multiple guidelines concerning their management, it continues to be challenging. Decision-making between surgical and endovascular procedures should be well established, but there is still a lack of consensus concerning the best treatment strategy. The aim of this manuscript is to offer an overview of the contemporary management of CLTI patients, with a focus on the concept that evidence-based revascularization (EBR) could help surgeons to provide more appropriate treatment, avoiding improper procedures, as well as too-high-risk ones.

METHODS

We performed a search on MEDLINE, Embase, and Scopus from 1 January 1995 to 31 December 2022 and reviewed Global and ESVS Guidelines. A total of 150 articles were screened, but only those of high quality were considered and included in a narrative synthesis.

RESULTS

Global Vascular Guidelines have improved and standardized the way to classify and manage CLTI patients with evidence-based revascularization (EBR). Nevertheless, considering that not all patients are suitable for revascularization, a key strategy could be to stratify unfit patients by considering both clinical and non-clinical risk factors, in accordance with the concept of individual residual risk for every patient. The recent BEST-CLI trial established the superiority of autologous vein bypass graft over endovascular therapy for the revascularization of CLTI patients. However, no-option CLTI patients still represent a critical issue.

CONCLUSIONS

The surgeon's experience and skillfulness are the cornerstones of treatment and of a multidisciplinary approach. The recent BEST-CLI trial established that open surgical peripheral vascular surgery could guarantee better outcomes than the less invasive endovascular approach.

Patient Characteristics in the Recording Courses of Vascular Diseases (Reccord) Registry: Comparison with the Voyager Pad Endovascular Cohort

Background: To compare the characteristics of a “real world” population included in a prospective registry to patients enrolled in a randomized, controlled trial (RCT) after endovascular revascularization (EVR) for symptomatic peripheral artery disease (PAD). Methods: The RECcording COurses of vasculaR Diseases (RECCORD) registry is an observational registry prospectively recruiting patients undergoing EVR for symptomatic PAD in Germany. VOYAGER PAD was an RCT which demonstrated the superiority of rivaroxaban and aspirin versus aspirin to reduce major cardiac and ischemic limb events following infrainguinal revascularization for symptomatic PAD. For this exploratory analysis, the clinical characteristics of 2.498 patients enrolled in RECCORD and of 4.293 patients from VOYAGER PAD who underwent EVR were compared. Results: The rate of patients aged ≥ 75 years was considerably higher in the registry (37.7 vs. 22.5%). More patients in the registry had undergone previous EVR (50.7 vs. 38.7%) or suffered from critical limb threatening ischemia (24.3 vs. 19.5%). Registry patients were more commonly active smokers (51.8 vs. 33.6%), but less frequently suffered from diabetes mellitus (36.4 vs. 44.7%). While statins (70.5 vs. 81.7%) were less frequently used, antiproliferative catheter technologies (45.6 vs. 31.4%) and postinterventional dual antiplatelet therapy (64.5 vs. 53.6%) were more commonly applied in the registry. Conclusions: There were many similarities but some clinically meaningful differences in clinical characteristics between PAD patients who underwent EVR and were included in a nationwide registry and PAD patients from the VOYAGER PAD trial.