Cilostazol and freedom from amputation after lower extremity revascularization

Abstract

Cilostazol, an antiplatelet agent with vasodilating properties, has not been well evaluated in conjunction lower extremity revascularization (LER). We evaluated the association between cilostazol and limb salvage after endovascular or open surgery for LER. Patients aged ≥65 years undergoing LER were identified from 2007 to 2008 Medicare Provider Analysis and Review and Carrier files using International Classification of Diseases-9 Edition-Clinical Modification and Current Procedural Terminology-4 codes. Covariates included demographics, comorbidities, and disease severity. Use of cilostazol was identified using National Drug Codes and Part D files. Outcomes were compared using χ(2) and Kaplan-Meier analyses and Cox regression. We identified 22,954 patients undergoing LER: 8128 (35.4%) with claudication, 3056 (13.3%) with rest pain, and 11,770 (51.3%) with ulceration/gangrene. Among them, 1999 patients (8.7%) used cilostazol before LER. More patients received endovascular (14,353) than open (8601) procedures. Cilostazol users had fewer amputations than nonusers at 30 days (7.8% vs 13.4%), 90 days (10.7% vs 18.0%), and 1 year (14.8% vs 24.0%; P < .0001 for all). Cox proportional hazards regression with adjustment for age, gender, race, comorbidities, type of procedure, and atherosclerosis severity showed noncilostazol users were more likely to undergo amputation ≤1 year after surgery (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.02-1.29; P = .02). Subgroup analyses using Cox proportional hazards models adjusted for age, gender, and comorbidities demonstrated significantly improved 1-year amputation-free survival for patients with renal failure (HR, 1.61; 95% CI, 1.28-2.02; P < .001) and diabetes (HR, 1.61; 95% CI, 1.36-1.92; P < .001) who were taking cilostazol. In patients undergoing LER, cilostazol use was associated with improved 1-year freedom from amputation. Patients with renal failure and diabetes also demonstrated a significant benefit from taking cilostazol. Further studies are needed to evaluate the benefits of cilostazol after LER.