Incidence and Risk Factors of Peripheral Arterial Occlusive Disease in a Prospective Cohort of 700 Adult Men Followed for 5 Years

Abstract

Merino et al. [1] describe a modestly sized prospective cohort of middleto older-aged men in an urban setting and determine the incidence of peripheral arterial occlusive disease (PAOD) over 5 years. A strength of this study is the rigorously measured ABI, definitions, and long, relatively complete follow-up. They use the standard AHA diagnostic definition of PAOD, namely, ABI \0.90. The defined incidence of PAOD was 12%, which is very similar to what has been reported in the US [2]. Most had moderate PAOD, with ABI [0.61. Risk factors included increased age and smoking. Not surprisingly, those with symptomatic atherosclerotic disease in other anatomic locations, i.e., cerebral and coronary beds, had a higher risk of symptomatic PAOD. These factors were an additive in risk. Interestingly, hypertension, diabetes, and an abnormal lipid profile were not associated with incident PAOD, possibly because of insufficient power or similar prevalence between groups. It must be understood that the magnitude of the atherosclerosis burden in symptomatic PAOD is great. Atherosclerosis is a chronic inflammatory disease and, if not treated, is progressive. A critical point for all surgeons and physicians is that PAOD is a marker for systemic cardiovascular risk [3]. This also means that asymptomatic PAOD should be diagnosed and treated medically. The current study highlights risk factors that predict those that have a higher risk of developing PAOD. For those with defined PAOD, appropriate medical therapy should be implemented. This includes smoking cessation, an ambulation program, antiplatelet therapy, and cholesterol reduction, primarily via HMG Co-A reductase agents (statins). Most patients with PAOD will not need any endoluminal or operative intervention except those with severe lifestyle-limiting claudication, rest pain, or tissue loss. This is primarily because any intervention is costly in terms of money, patient morbidity, and durability limits. Nationally, with health-care reform just passed, emphasis will be placed on preventative therapies. It is not clear if PAOD will be one of those areas, but I believe it should be considered. For example, preventative therapy that should be paid for by insurers is structured exercise, which can stabilize symptoms and decrease progressive PAOD [4]. This also has direct cardiovascular benefits. In patients with PAOD, antiplatelet therapy seems reasonable but needs to be balanced against bleeding risk because recent data suggest that aspirin may not decrease incident cardiovascular events [5]. Treating hypercholesterolemia is not controversial. Statins are the mainstay and seem to have pleotropic effects in addition to cholesterol reduction. This was recently exemplified by the JUPITER trial which randomized patients with elevated hsCRP and borderline LDL levels to a statin or a placebo [6]. A significant reduction in cardiovascular events was observed with statin treatment, and the hsCRP was reduced with statin treatment. Furthermore, hypertension treatment is often neglected and should also be aggressively managed. Angiotensin-converting enzyme inhibitors are a good class of medications in this patient population. Although the prevalence of hypertension was not statistically different among patients in this cohort, it is unclear how rigorously blood pressure was measured and how the readings varied over time. In summation, the current article adds to the growing body of international literature that highlights the incidence of PAOD and the associated risks in men. These data are P. Henke (&) Section of Vascular Surgery, University of Michigan, Ann Arbor, MI 48109, USA e-mail: henke@umich.edu