Efficacy and safety of antiplatelet therapy intensification with clopidogrel after coronary artery bypass grafting in patients with diffuse coronary artery disease: preliminary results of a one-year study

Aim. To study the clinical outcomes and the frequency of bypass graft occlusions in patients with diffuse coronary artery disease (CAD) and small (<1,5 mm) diameter of bypassed coronary arteries (CA) one year after coronary artery bypass grafting (CABG) while taking various antithrombotic therapies (ATT) (aspirin and a combination of aspirin with clopidogrel). Material and methods. This prospective randomized study included 94 patients with a stable diffuse multivessel CAD with a small (<1,5 mm) vessel diameter, who underwent uncomplicated CABG. The patients were randomized into 2 following groups: acetylsalicylic acid (ASA) monotherapy (n=41) and ASA+clopidogrel therapy (n=53). The median follow-up (interquartile range) was 20 (12; 24 months). All participants underwent computed tomographic (CT) bypass angiography. Results. There were a total of 349 bypasses with a total occlusion rate of 54 (16%). The bypass occlusion rate in the ASA and ASA+clopidogrel groups was very close as follows: 19 vs 13% (p=0,191). In the subanalysis of the bypass graft function related to arteries with a diameter <1,5 mm, occlusions developed more often in the ASA group (39 vs 12%, p=0,005). This difference was formed due to the gap between the groups in the bypass graft occlusion rate related arteries of the smallest diameter (≲1 mm) (60 vs 17%, p=0,006). The angina recurrence rate with aspirin monotherapy was slightly higher than with "enhanced" ATT (20 vs 13%, p=0,480). Conclusion. Bypass graft occlusions related to arteries of small (<1,5 mm) diameter, assessed one year after CABG, develop significantly less often with ASA+clopidogrel combination therapy.