A Propensity-Matched Study of the Association of Peripheral Arterial Disease With Cardiovascular Outcomes in Community-Dwelling Older Adults

Abstract

The association between peripheral arterial disease (PAD) and outcomes has not been studied in a propensity-matched population of community-dwelling older adults. A public-use copy of the Cardiovascular Health Study (CHS) data was analyzed to test the hypothesis that baseline PAD is associated with increased all-cause mortality and cardiovascular morbidity. Of the 5,795 CHS participants, 5,630 had data on baseline ankle-brachial index, and 767 had PAD, defined as ankle-brachial index <0.9. Propensity scores for PAD were calculated for each participant using 66 baseline covariates and were used to match 679 pairs of participants with and without PAD. Matched Cox regression models were used to estimate associations of PAD with outcomes during a median follow-up period of 7.5 years. Overall, 55% of matched participants died from all causes during 9,958 patient-years of follow-up. All-cause mortality occurred in 61% (rate 8,710/100,000 patient-years) and 50% (rate 6,503/100,000 patient-years) of participants, respectively, with and without PAD (matched hazard ratio for PAD vs no PAD 1.47, 95% confidence interval (CI) 1.23 to 1.76, p <0.0001). Prematch unadjusted, multivariable-adjusted, and propensity-adjusted hazard ratios for PAD-associated all-cause mortality were 2.90 (95% CI 2.61 to 3.21, p <0.0001), 1.53 (95% CI 1.36 to 1.71, p <0.0001), and 1.57 (95% CI 1.39 to 1.78, p <0.0001), respectively. Matched hazard ratios for PAD for incident heart failure and symptomatic PAD were 1.32 (95% CI 1.00 to 1.73, p = 0.052) and 3.92 (95% CI 2.13 to 7.21, p <0.0001), respectively. In conclusion, in a propensity-matched well-balanced population of community-dwelling older adults, baseline PAD was associated with increased all-cause mortality and cardiovascular morbidity.