Secondary Prevention and Mortality in Peripheral Artery Disease

Abstract

Background— Whether individuals with peripheral artery disease (PAD) identified by screening ankle-brachial index benefit from preventive therapies to reduce cardiovascular risk is unknown. We aimed to determine the number of US adults with PAD who are not receiving preventive therapies and whether treatment is associated with reduced mortality in PAD subjects without known cardiovascular disease. Methods and Results— We analyzed data from the National Health and Nutrition Examination Survey (NHANES) 1999 to 2004 with mortality follow-up through December 31, 2006. We defined PAD as an ankle-brachial index ≤0.90. Of 7458 eligible participants ≥40 years, weighted PAD prevalence was 5.9±0.3% (mean±SE), corresponding to ≈7.1 million US adults with PAD. Statin use was reported in only 30.5±2.5%, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use in 24.9±1.9%, and aspirin use in 35.8±2.9%, corresponding to 5.0 million adults with PAD not taking statins, 5.4 million not taking angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, and 4.5 million not receiving aspirin. After adjustment for age, sex, and race/ethnicity, PAD was associated with all-cause mortality (hazard ratio, 2.4; 95% confidence interval, 1.9 to 2.9; P <0.0001). Even after exclusion of individuals with known cardiovascular disease, subjects with PAD had higher mortality rates (16.1±2.1%) than subjects without PAD or cardiovascular disease (4.1±0.3%), with an adjusted hazard ratio of 1.9 (95% confidence interval, 1.3 to 2.8; P =0.001). Among PAD subjects without cardiovascular disease, use of multiple preventive therapies was associated with 65% lower all-cause mortality (hazard ratio, 0.35; 95% confidence interval, 0.20 to 0.86; P =0.02). Conclusions— Millions of US adults with PAD are not receiving secondary prevention therapies. Treatment with multiple therapies is associated with reduced all-cause mortality.