Prospects for Multimodality Imaging in Peripheral Artery Disease
Asymptomatic peripheral artery disease (PAD) is an important marker for elevated risk of coronary and cerebrovascular disease. Symptomatic PAD adds to this burden by affecting quality of life and limiting function. This runs the spectrum of claudication impeding walking and mobility to critical limb ischemia with rest pain, gangrene, and risk of major amputation.1
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Symptomatic PAD is a product of several abnormal factors. These include impaired blood flow to muscle and limb tissue because of stenosis or occlusion of the large conduit arteries, endothelial dysfunction affecting blood flow in all arteries, and abnormal muscle bioenergetics.2 Therapies for symptomatic PAD target these defects.2–7 For example, revascularization improves blood flow in large arteries, and risk factor modification, such as smoking cessation, walking programs, and hydroxy-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, aims to improve endothelial function and muscle bioenergetics during exercise. Arteriogenesis and angiogenesis of the small arteries and capillaries may be mechanisms for some of the benefits from risk factor modification and are the foundation for cell-based therapies that offer the potential for improved perfusion in critical limb ischemia.
Current Clinical and Research Approaches to Assessing PAD
Currently, the clinical diagnosis of PAD relies on clinical symptoms, clinical signs, and physiological tests of blood flow at rest and exercise. These include …