A Prognostic Risk Index for Long-term Mortality in Patients With Peripheral Arterial Disease

Abstract

Prognostic information in peripheral arterial disease (PAD) may provide the basis for optimal management strategies at an early stage. This study aimed to develop a prognostic risk index for long-term mortality in patients with PAD. In a single-center observational cohort study, 2642 patients with an ankle-brachial index of 0.90 or lower were randomly divided into derivation (n = 1332) and validation (n = 1310) cohorts. Cox regression analysis with stepwise backward elimination identified predictors of 1-year, 5-year, and 10-year mortality in the derivation cohort. Weighted points were assigned to each predictor. Index discrimination was determined in both the derivation and validation cohorts. During 10 years of follow-up, 42.2% and 40.4% of patients died in the derivation and validation cohorts, respectively. The risk index for 10-year mortality (+ points) included renal dysfunction (+12), heart failure (+7), ST-segment changes (+5), age greater than 65 years (+5), hypercholesterolemia (+5), ankle-brachial index lower than 0.60 (+4), Q-waves (+4), diabetes (+3), cerebrovascular disease (+3), and pulmonary disease (+3). Statins (-6), aspirin (-4), and beta-blockers (-4) were associated with reduced 10-year mortality. Patients were stratified into low (<0 points), low-intermediate (0-5 points), high-intermediate (6-9 points), and high (>9 points) risk categories, according to risk score. Ten-year mortality rates were 22.1%, 32.2%, 45.8%, and 70.4%, respectively (P < .001) and comparable to mortality in the validation cohort. C statistics demonstrated good discrimination in both the derivation (0.72) and validation cohorts (0.73). A prognostic risk index for long-term mortality stratified patients with PAD into different risk categories. This may be useful for risk stratification, patient counseling, and medical decision making.