Antiplatelet and anticoagulant drugs for prevention of restenosis/reocclusion following peripheral endovascular treatment.

BACKGROUND: Peripheral arterial disease (PAD) is frequently treated by balloon angioplasty. Restenosis/reocclusion of the dilated segments occurs often depending on length of occlusion, lower leg outflow, stage of disease and presence of cardiovascular risk factors. To prevent reocclusion, patients are treated with antithrombotic agents.
OBJECTIVES: To determine whether any antithrombotic drug is more effective in preventing reocclusion after peripheral endovascular treatment, compared to another antithrombotic drug, no treatment, placebo, or other vasoactive drugs. SEARCH STRATEGY: We searched the Cochrane Peripheral Vascular Diseases Group's trials register (last searched April 2004), the Cochrane Central Register of Controlled trials (CENTRAL Issue 2, 2004), MEDLINE and EMBASE (last searched June 2004). SELECTION CRITERIA: Randomised trials were categorised as A (double or single blinded) or B (not blinded). Participants included patients with symptomatic PAD treated by endovascular revascularisation of the pelvic or femoropopliteal arteries. Interventions were anticoagulant, antiplatelet or other vasoactive drug therapy compared with no treatment, placebo, or any other vasoactive drug. Clinical endpoints were re-obstruction, amputation, death, myocardial infarction, stroke and major bleeding. DATA COLLECTION AND ANALYSIS: Details of the number of randomised patients, treatment, study design, study category, allocation concealment and patient characteristics were extracted. Analysis was based on intention-to-treat data. To examine the effects of binary outcomes such as amputation and major bleeding, odds ratios were computed using a fixed effect model. The 95% confidence intervals of the effect sizes were calculated. MAIN
RESULTS: A 60% reduction of recurrent obstruction was found with aspirin (ASA) 330 mg combined with dipyridamol (DIP) as compared to placebo at 12 months follow-up. At six months following endovascular treatment, a positive effect on patency was found with 50 to 100 mg ASA combined with DIP (n = 356). However, this was not significant. ASA/DIP tended towards showing a superior effect on patency after femoropopliteal angioplasty compared with VKA at three, six, and twelve months. Periinterventional treatment with LMWH in femoropopliteal obstructions resulted in significantly lower restenosis/reocclusion rates than with unfractionated heparin. AUTHORS'
CONCLUSIONS: Aspirin 50 to 300 mg started prior to femoropopliteal endovascular treatment appears to be the most effective and is safe. Clopidogrel might be an alternative, but data are lacking. Abciximab might be a useful adjunctive for high risk patients with long segmental femoropopliteal interventions. Low molecular weight heparin seems to be more effective in preventing reocclusion or restenosis than unfractionated heparin.