Antiplatelet Agents for Preventing Thrombosis after Peripheral Arterial Bypass Surgery

Summary

A Cochrane review [Abstract] 1 included 16 studies with a total of 5 683 subjects to determine the effects of antiplatelet agents for the prevention of thrombosis in people with lower limb atherosclerosis who were undergoing femoropopliteal or femorodistal bypass grafting. Nine different treatment groups were evaluated: aspirin (ASA) or aspirin and dipyridamole (ASA/DIP) versus placebo or nothing (6 studies); ASA or ASA/DIP versus pentoxifylline (2 studies); ASA/DIP versus indobufen (1 study); ASA or ASA/DIP versus vitamin K antagonists (2 studies); ASA/DIP versus low molecular weight heparin (1 study); ticlopidine versus placebo (1 study); ASA versus prostaglandin E1 (1 study); ASA versus naftidrofuryl (1 study); and clopidogrel and ASA versus ASA alone (1 study).

There was improved graft patency in the aspirin ASA or ASA/DIP treatment group compared with placebo or nothing (OR 0.42, 95% CI 0.22 to 0.83; 6 studies, n=952). This effect was not seen for venous grafts alone at any of the time points, but was observed for all time points in prosthetic grafts, including the final time point of 12 months (OR 0.19, 95% CI 0.10 to 0.36; 4 studies, n=222). There was no difference for any of the side effects, including general, gastrointestinal, bleeding and wound/graft infection. Amputations, cardiovascular events and mortality were also similar between the treatment groups.

There were no differences between ASA or ASA/DIP versus vitamin K antagonists for primary graft patency at 3, 6, 12 or 24 months (2 studies, n=2781), and there was also no evidence of a difference for limb amputation, cardiovascular events or mortality.

One study (n=851) evaluated clopidogrel and ASA versus ASA alone, and for all grafts there was no evidence of a difference of primary patency at 24 months. There was increased total bleeding in the clopidogrel and ASA group (OR 2.65, 95% CI 1.69 to 4.15) from an increase in mild (OR 2.34, 95% CI 1.37 to 4.00), and moderate bleeding (OR 4.13, 95% CI 1.37 to 12.45), but no difference in severe or fatal bleeding. There was no difference between the treatment groups for limb amputation or mortality.