PAD Prediction of Future CCVD Morbidity and Mortality and All-Cause Mortality

P eripheral arterial disease (PAD) has been estimated to reduce quality of life in approximately 2 million symptomatic Americans, 1 and millions more Americans without claudication are likely to suffer PAD-associated impairment. 2 PAD is a strongly age-dependent condition that contributes significantly to morbidity and healthcare expenditures in the elderly: There are 413 000 discharges per year with chronic PAD, 88 000 hospitalizations involving lower-extremity ar-teriography, and 28 000 discharges citing embolectomy or thrombectomy of lower-limb arteries. 3 Figures for prevalence of asymptomatic PAD are several-fold higher. These figures were based on National Hospital Discharge Survey and National Vital Statistics System 1985 to 1987 US data; numbers of procedures had increased in the prior decade 3 and are likely to have increased in the intervening years as the population continues to age. Even though few deaths were directly attributed to PAD, PAD has potent mortality implications. Although symptomatic disease directly affects functional capacity and quality of life by restricting ambulation, asymptomatic disease is also important, not only because it may augur risk of future compromised ambulation, lower-extremity ulcers, or need for vascular surgery or amputation, but perhaps most importantly because asymptomatic and symptomatic PAD are consistent and powerful independent predictors of coronary artery disease (CAD) and cerebrovas-cular disease (CBVD) events and mortality. The evidence relating PAD to prevalent and incident cardiac and cerebro-vascular disease (CCVD) forms the focus of the present report. yielded all abstracts with title words " peripheral artery disease, " " peripheral arterial disease, " or " peripheral vascular disease. " These were reviewed for content pertaining to co-occurrence with or prediction by PAD of atherosclerotic disease and total mortality. Additional citations were identified from bibliographies of culled articles and consultation with experts. Identified citations with original epidemiological data pertaining to the relation of lower-extremity PAD to cardiovascular and overall morbidity and mortality were reviewed. Data were stratified into cross-sectional or retrospective studies versus prospective studies, to distinguish the cross-sectional association of PAD with prevalent CCVD from the prognostic significance of PAD for incident CCVD and mortality. All studies with defined populations, PAD assessment, and outcome assessment for CCVD morbidity and mortality (or total mortality) were considered. Population characteristics, criteria for PAD and for CCVD outcomes, coprevalence of CCVD with PAD (cross-sectional data), and risk ratios and confidence intervals relating PAD to incident CCVD and mortality outcomes (prospective data) were extracted. Covariates adjusted in the studies' multivariable …