Comparison of Lower Extremity Bypass and Peripheral Vascular Intervention for Chronic Limb-Threatening Ischemia in the Medicare-Linked Vascular Quality Initiative.

INTRODUCTION: There is a relative lack of comparative effectiveness research on revascularization for patients with chronic limb-threatening ischemia (CLTI). We examined the association between lower extremity bypass (LEB) versus peripheral vascular intervention (PVI) for CLTI and 30-day and 5-year all-cause mortality and 30-day and 5-year amputation.

METHODS: Patients undergoing LEB and PVI of the below the knee popliteal and infrapopliteal arteries between 2014 and 2019 were queried from the VQI, and outcomes data were obtained from the Medicare claims-linked Vascular Implant Surveillance and Interventional Outcomes Network (VISION) database. Propensity scores were calculated on 15 variables using a logistic regression model to control for imbalances between treatment groups. A 1:1 matching method was used. Kaplan-Meier survival curves and hierarchical Cox proportional hazards regression with a random intercept for site and operator nested in site to account for clustered data compared 30-day and 5-year all-cause mortality between groups. Thirty-day and 5-year amputation were subsequently compared using competing risk analysis to account for the competing risk of death.

RESULTS: There was a total of 2,075 patients in each group. The overall mean age was 71 ± 11 years, 69% were male, and 76% were white, 18% were black, and 6% were of Hispanic ethnicity. Baseline clinical and demographic characteristics in the matched cohort were balanced between groups. There was no association between all-cause mortality over 30 days and LEB vs. PVI (cumulative incidence 2.3% vs. 2.3% by Kaplan Meier, log-rank P-value=0.906; HR 0.95, 95% CI 0.62-1.44, P-value=0.80). All-cause mortality over 5 years was lower for LEB vs. PVI (cumulative incidence 55.9% vs. 60.1% by Kaplan Meier, log-rank P-value <0.001; HR 0.77; 95% CI 0.70-0.86, P-value <0.001). Accounting for competing risk of death, amputation over 30 days was also lower in LEB vs. PVI (cumulative incidence function 1.9% vs. 3.0%, Fine and Gray P-value=0.025; sHR 0.63; 95% CI 0.42-0.95, P-value=0.025). There was no association between amputation over 5 years and LEB vs. PVI (cumulative incidence function 22.6% vs. 23.4%, Fine and Gray P-value=0.184; sHR 0.91; 95% CI 0.79-1.05, P-value=0.184).

CONCLUSION: In the VQI linked Medicare registry, LEB vs. PVI for CLTI was associated with a lower risk of 30-day amputation and 5-year all-cause mortality. These results will serve as a foundation to validate recently published randomized controlled trial data, and to broaden the comparative effectiveness evidence base for CLTI.