MEND-CABG II trial does not suggest improved outcomes with the novel drug MC1 in patients undergoing high risk coronary artery bypass surgery
April 1, 2008 By Vijayalakshmi Kunadian MBBS MD MRCP 
WikiDoc News previously reported on the results of the MEND CABG II trial based on the press release from Medicure Inc. (2). The complete results of this trial were presented by Dr. John Alexander on behalf of the investigators at the ACC 08 Annual Scientific Sessions today in Chicago.
The MEND-CABG was a randomized, double-blind, placebo-controlled, multicenter study to evaluate the cardioprotective effects of MC-1 in patients undergoing high-risk coronary artery bypass graft surgery.
CABG is associated with post-operative complications which include death (1-3%), myocardial infarction (2-15%), stroke (2-5%), acute renal injury (5-8%) and ischemia reperfusion injury. MC-1 (pyridoxol-5-phosphate) is a naturally occurring metabolite of pyridoxine (vitamin B6). It blocks the intracellular influx of calcium and thereby reduces cell damage during ischemia and reperfusion. It was previously demonstrated to reduce infarct size following percutaneous coronary intervention and has been demonstrated to have an acceptable safety profile.
The initial phase II MEND-CABG study of 901 patients demonstrated that among CABG patients with an elevated CK (creatine kinase), there was a significant improvement in the primary endpoint of death, non fatal myocardial infarction and non fatal stroke.
The MEND-CABG II study assessed the cardioprotective effect and safety of MC-1 (250 mg/day for 30 days). Patients received their first dose (MC-1 250 mg) 3-10 hours before surgery. The first post-operative dose was given 24 ± 8 hours after the first pre-operative dose and it was administered for 30 days. For patients unable to take oral medications, an intravenous (IV) dose of MC-1 5 mg was administered for 4 post-operative days.
The MEND-CABG trial consisted of a total of 7230 patients of which 3023 were randomized either to MC-1 (n=1519) or matching placebo (n=1504). Follow-up results were available in 99.4% of cases in the MC-1 group and 98.8% of cases in the placebo group. There was no difference in the baseline characteristics between the two study groups. The primary endpoint occurred in 9.3% of cases in the MC-1 group and 9.0% of cases in the placebo group [RR 1.04, (0.83-1.3) p=0.76].
A sub-group analyses that evaluated the results by age, diabetes mellitus, hypertension, renal failure and an analysis based on the region patients were recruited from (US, Germany or Canada) and IV use did not demonstrate significant differences in the outcomes between the two groups.
- Presented at the ACC Annual Scientific Sessions April 1, 2008 Chicago.