Risk Factors for Mortality Among Individuals With Peripheral Arterial Disease

Morbidity and mortality from peripheral arterial disease (PAD) continues to increase. Traditional cardiovascular risk factors are implicated in the development of PAD, yet the extent to which those risk factors correlate with mortality in such patients remains insufficiently assessed. Using data from the 1999 to 2004 National Health and Nutrition Examination Survey, Cox proportional hazards models were used to examine the association of cardiovascular risk factors and all-cause and cardiovascular mortality. A total of 647 individuals ≥40 years old with PAD (i.e., ankle-brachial index [ABI] ≤ 0.9) were followed for a median of 7.8 years. There were 336 deaths, of which 98 were attributable to cardiovascular disease. Compared with never smokers, current (hazard ratio [HR] 2.45, 95% confidence interval [CI] 1.62 to 3.71) and former (HR 1.62, 95% CI 1.14 to 2.29) smokers with PAD had higher rates of death. Moderate or vigorous physical activity of ≥10 minutes monthly was associated with lower death rates (HR 0.63, 95% CI 0.44 to 0.91). Also associated with increased rates of cardiovascular death were an ABI of <0.5 (HR 2.56, 95% CI 1.28 to 5.15, compared with those with an ABI of 0.7 to 0.9) and diabetes mellitus (HR 2.50, 95% CI 1.33 to 4.73). Neither C-reactive protein nor body mass index was associated with mortality. In conclusion, tobacco use increased the risk of all-cause and cardiovascular death, whereas physical activity was associated with a decreased mortality risk. A low ABI and diabetes were also predictive of cardiovascular death.