Peripheral Arterial Disease

May be defined as systemic atherosclerosis of the aorta, iliac arteries, and lower extremities

Peripheral arterial disease (PAD) may be defined as systemic atherosclerosis of the aorta, iliac arteries and lower extremities and is associated with significant morbidity and mortality (1;2). The vast majority of patients with PAD also have significant concomitant coronary artery disease (CAD) and a high proportion of morbidity and mortality in these patients is related to myocardial infarction, ischaemic stroke or cardiovascular death (1). In those patients with PAD but no evidence of CAD, the same relative risk of death from either cardiac or cerebrovascular causes is seen as in patients whose main diagnosis is CAD, further reinforcing the systemic nature of this condition (1;3).

It is estimated that approximately 27 million people in Western Europe and North America have PAD (4;5). Whilst 10 to 35% of patients present with classical claudication symptoms, between 20 and 40% have atypical leg pain (1). Almost 50% of patients may be asymptomatic, with diagnosis made by the ankle-brachial index (1;6-8). The 5 year rate of non fatal cardiovascular events (including MI and stroke) among patients with symptomatic PAD is around 20%, with mortality ranging from 15 to 30% (1;8). Of the 1 to 2% of patients who develop critical limb ischaemia, up to 25% may ultimately require amputation and annual mortality in these patients may be as high as 25% (9).

The risk factors that contribute to the development of PAD are the same as those seen for CAD or cerebrovascular disease: increased age, hypertension, hyperlipidaemia, diabetes mellitus and smoking (10). Other factors associated with the development of PAD include chronic kidney disease (CKD), low serum 1,23-hydroxy-vitaminD3 levels, and elevated inflammatory biomarkers such as C-reactive protein beta-2 microglobulin and cystatin C (11-14).

Treatment of PAD requires a multi-factorial approach encompassing risk factor modification, cardiovascular event reduction, limb viability and symptom improvement. Hypertension, hyperlipidaemia and glycaemic control in diabetes mellitus should all be treated to target levels (1;15), and support with smoking cessation is of particular importance (1). The combination of both exercise therapy and pharmacotherapy (anti-platelets) may result in significant improvement in symptoms in patients with claudication. For those patients presenting with more advanced disease such as acute limb ischaemia, critical limb ischaemia or severely limiting symptoms, revascularisation may be necessary with many guidelines now recommending an endovascular first approach (16)-(17).