Reduction of myocardial ischemic injury following coronary intervention (the MC-1 to Eliminate Necrosis and Damage trial).

Myocardial ischemic injury complicating acute myocardial infarction (AMI) and coronary revascularization procedures remains an unresolved clinical dilemma. In preclinical studies, treatment with pyridoxal-5'-phosphate monohydrate (MC-1), a vitamin B6 metabolite, has demonstrated cardioprotective effects. Sixty patients scheduled for elective percutaneous coronary intervention (PCI) who had clinically high-risk characteristics for ischemic complications were randomized to treatment with MC-1 or placebo in a 2:1 double-blinded fashion. The primary end point was defined as infarct size as measured by area under the curve creatine kinase MB (CK-MB) enzymes. Secondary end points included periprocedural ischemia as assessed by continuous electrocardiographic monitoring, 30-day major adverse cardiac events, and net clinical safety, which included liver function testing. The primary end point, median periprocedural CK-MB area under the curve, was reduced from 32.9 ng/ml in the placebo group to 18.6 ng/ml with MC-1 treatment (p = 0.038), reflecting a shift in the distribution of CK-MB. By categorical classification, the occurrence of 30-day nonfatal AMI did not differ between groups. There were no deaths, and 30-day composite adverse event rates were similar (17.9% MC-1 vs 15.0% placebo, p = 1.0). There were no significant differences in ischemia parameters per continuous electrocardiographic monitoring, and no safety issues were identified. In this phase II pilot study, treatment of high-risk patients who underwent PCI with MC-1 was associated with a decrease in the total amount of CK-MB released after PCI. These results support the evaluation of MC-1 in pivotal trials of patients at risk for developing myocardial ischemia, infarction, or reperfusion injury.