Antithrombotic therapy in peripheral vascular disease

Atherosclerotic peripheral vascular disease is symptomatic as intermittent claudication in 2-3% of men and 1-2 % of women aged over 60 years. However, the prevalence of asymptomatic peripheral vascular disease, generally shown by a reduced ankle to brachial systolic pressure index, is three to four times greater. Peripheral vascular disease is also a significant cause of hospital admission, and is an important predicator of cardiovascular mortality. Pain at rest and critical ischaemia are usually the result of progression of atherosclerotic disease, leading to multilevel arterial occlusion. Other causes of arterial insufficiency—including fibromuscular dysplasia, inflammatory conditions, and congenital malformations—are much rarer.

Ischaemic ulcer on foot

Therapeutic objectives in peripheral vascular disease include relieving symptoms and preventing the disease, and any associated events, progressing.

The symptoms of peripheral vascular disease are progressive. A claudicating patient encouraged to exercise tends to report a symptomatic improvement. This effect is generally not accepted to be an improvement in the diseased segment of blood vessel, but the formation of collateral vessels perfusing the ischaemic tissue.

Vasodilating agents, such as naftidrofuryl, have little value in managing claudication and peripheral vascular disease as their effect is small and does not stop progression of the disease. Cilostazol has been shown to increase absolute walking distance in some patients by up to 47%. However, it has no clear antithrombotic effect and has not been shown to stop disease progression.

Unfortunately, not all progression is amenable to improvement and, without the appropriate risk factor management, progression to rest pain and necrosis can be rapid.