Ramipril Treatment of Claudication: Oxidative Damage and Muscle Fibrosis

Peripheral artery disease (PAD) is a manifestation of atherosclerosis that produces progressive narrowing and occlusion of the arteries supplying the lower extremities. The most common clinical manifestation of PAD is claudication, i.e., a severe functional limitation identified as gait dysfunction and walking-induced leg muscle pain relieved by rest. The standard therapies for claudication include the medications cilostazol and pentoxifylline, supervised exercise therapy and operative revascularization. Recent data demonstrated that 24 weeks of treatment with the angiotensin-converting enzyme (ACE) inhibitor Ramipril produces improvements in the walking performance of patients with claudication that are higher than those of cilostazol and pentoxifylline and similar to those produced by supervised exercise therapy and operative revascularization. The mechanisms by which Ramipril therapy produces this impressive improvement in the functional capacity of claudicating patients remain unknown. The Investigators hypothesize that treatment of claudicating PAD patients with Ramipril will improve walking performance and quality of life by improving the myopathy of the gastrocnemius. Improved myopathy is a consequence of reduced oxidative damage, reduced TGF-β1 production by vascular smooth muscle cells and reduced collagen deposition in the affected gastrocnemius.