Use of angiotensin-converting enzyme inhibitors and freedom from amputation after lower extremity revascularization

OBJECTIVE: Angiotensin-converting enzyme inhibitors (ACEIs) have not been well evaluated in conjunction with lower extremity revascularization (LER). This study evaluated freedom from amputation in patients who underwent either an open (OPEN) or endovascular (ENDO) revascularization with and without utilization of an ACEI. MATERIALS AND METHODS: Patients who underwent LER were identified from 2007–2008 Medicare Provider Analysis and Review files. Demographics, comorbidities, and disease severity were obtained. Post-procedural use of an ACEI was confirmed using combining them with National Drug Codes and Part D Files. Outcomes were analyzed using chi-square analysis, Kaplan–Meier test, and Cox regression. RESULTS: We identified 22,954 patients who underwent LER: 8,128 (35.4%) patients with claudication, 3,056 (13.3%) with rest pain, and 11,770 (51.3%) with ulceration or gangrene. More patients underwent ENDO (14,353) than OPEN (8,601) revascularization and 38% of the cohort was taking an ACEI. Overall, ACEI utilization compared to patients not taking ACEI was not associated with lower amputation rates at 30 days (13.5% vs. 12.6%), 90 days (17.7% vs. 17.1%), or 1 year (23.9% vs. 22.8%) (P>0.05 for all). After adjustment for comorbidities, ACEI utilization was associated with higher amputation rates for patients with rest pain (hazard ratio: 1.4; 95% confidence interval: 1.1–1.8). CONCLUSION: ACEI utilization was not associated with overall improved rates of amputation-free survival or overall survival in the vascular surgery population. However, an important finding of this study was that patients presenting with a diagnosis of rest pain and taking an ACEI who underwent a LER had statistically higher amputation rates and a lower amputation-free survival at 1 year. Further analysis is needed to delineate best medical management for patients with critical limb ischemia and taking ACEI who undergo vascular revascularization.