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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. [ABSTRACT FROM AUTHOR]

BACKGROUND: The clinical significance of the interaction between clopidogrel and proton pump inhibitors (PPIs) remains unclear. METHODS AND RESULTS: We examined the relationship between PPI use and 1-year cardiovascular events (cardiovascular death, myocardial infarction, or stroke) in patients with acute coronary syndrome randomized to clopidogrel or ticagrelor in a prespecified, nonrandomized subgroup analysis of the Platelet Inhibition and Patient Outcomes (PLATO) trial. The primary end point rates were higher for individuals on a PPI (n=6539) compared with those not on a PPI (n=12 060) at randomization in both the clopidogrel (13.0% versus 10.9%; adjusted hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.04-1.38) and ticagrelor (11.0% versus 9.2%; HR, 1.24; 95% CI, 1.07-1.45) groups. Patients on non-PPI gastrointestinal drugs had similar primary end point rates compared with those on a PPI (PPI versus non-PPI gastrointestinal treatment: clopidogrel, HR, 0.98; 95% CI, 0.79-1.23; ticagrelor, HR, 0.89; 95% CI, 0.73-1.10). In contrast, patients on no gastric therapy had a significantly lower primary end point rate (PPI versus no gastrointestinal treatment: clopidogrel, HR, 1.29; 95% CI, 1.12-1.49; ticagrelor, HR, 1.30; 95% CI, 1.14-1.49). CONCLUSIONS: The use of a PPI was independently associated with a higher rate of cardiovascular events in patients with acute coronary syndrome receiving clopidogrel. However, a similar association was observed between cardiovascular events and PPI use during ticagrelor treatment and with other non-PPI gastrointestinal treatment. Therefore, in the PLATO trial, the association between PPI use and adverse events may be due to confounding, with PPI use more of a marker for, than a cause of, higher rates of cardiovascular events. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Unique identifier: NCT00391872. [ABSTRACT FROM AUTHOR]