Clopidogrel Treatment and the MEND-CABG II Trial

Abstract

To the Editor: The MEND-CABG (MC-1 to Eliminate Necrosis and Damage in Coronary Artery Bypass Graft Surgery Trial) II investigators have shown that pyridoxal 5 -phosphate monohydrate (MC-1) did not reduce cardiovascular death or nonfatal myocardial infarction (MI) in intermediateto high-risk patients undergoing coronary artery bypass graft (CABG) surgery. According to their data, there were no significant differences in concomitant medical therapies during hospitalization between the MC-1 and placebo groups (Table 4). Clopidogrel, an adenosine diphosphate receptor antagonist, is another important, widely used antiplatelet drug for reducing ischemic events in patients with acute coronary syndrome. The benefit of clopidogrel use before or after CABG is controversial. Kapetanakis et al reported that clopidogrel administration increased the risk for hemostatic reoperation and the requirements for blood product transfusions during and after off-pump CABG. But McLean et al showed that early clopidogrel treatment among MI patients undergoing CABG was not associated with an increase in the rate of perioperative bleeding and found a non– statistically significant reduction in 30-day ischemic events. Clopidogrel treatment may therefore be an important confounder for the analysis of the MEND-CABG II results, whether its effects are beneficial or harmful. However, the authors did not show how many patients received clopidogrel in their study and whether there were any differences in clopidogrel use between the MC-1 and placebo groups. Given the large size of this trial, it would also be interesting to perform a substudy to assess whether clopidogrel therapy can reduce cardiovascular death or nonfatal MI rates.