Abstract 17063: The Effect of Clopidogrel Plus Aspirin versus Aspirin Only on Progression of Native Coronary Artery Disease 1 Year After CABG: Analysis From the CASCADE Randomized Trial
Introduction: Clopidogrel improves patient outcomes after acute coronary syndrome and percutaneous coronary intervention. To this date, the effect of clopidogrel on native coronary artery disease (CAD) after coronary artery bypass grafting (CABG) has not been described. The CASCADE randomized controlled trial was designed to evaluate whether adding clopidogrel to aspirin inhibits saphenous vein graft hyperplasia and occlusion. In this secondary analysis, we examined whether adding clopidogrel to aspirin was protective against the progression of native CAD after CABG, compared to aspirin alone.
Methods: In the CASCADE trial, 113 patients were randomized to receive aspirin 162 mg plus clopidogrel 75 mg daily or aspirin 162 mg plus placebo daily for 1 year after CABG. For this post-hoc analysis, 2 expert physicians, blinded to patient treatment, independently reviewed coronary angiograms performed preoperatively and 1 year after CABG. We compared the incidence of progressive CAD and new stenoses in relation to graft anastomosis site and the existence of bypass graft failure between the clopidogrel and placebo groups.
Results: Baseline clinical and operative characteristics were similar in the clopidogrel and placebo groups. A total of 201 stenoses and 24 occlusions were identified at preoperative angiography, and 5 new stenoses were detected at postoperative angiography. At 1 year, there were 35 changes of which 30 were progressive stenoses and 5 were new stenoses. The incidence of new and progressive stenoses in the clopidogrel + aspirin group was equivalent to the aspirin only group [20.2% (22/109) vs. 13.4% (13/97), respectively, p=0.2], and the stenoses were similarly distributed [proximal to graft: 20.4% (19/93) vs. 14.6%(12/82), distal: 16.7% (1/6) vs. 0% (0/3), non-grafted segment: 20.0% (2/10) vs. 8.3% (1/12); p > 0.3]. Finally, the incidence of progressive native CAD was equivalent whether bypass graft failure had developed or not [graft failure 26.1% (6/23) vs. no graft failure 15.8% (29/183), p = 0.2].
Conclusions: Compared to aspirin only, adding clopidogrel to aspirin did not reduce the progression of native coronary artery disease 1 year after CABG. These findings may help guide post-CABG antiplatelet therapy.
- © 2013 by American Heart Association, Inc.