Intra-Coronary Administration of Tacrolimus Prior to First-Balloon Inflation Attenuates Infarct Size and Improves Left Ventricular Function in Patients with ST-segment Elevation Myocardial Infarction (COAT-STEMI) Undergoing Primary Coronary Intervention

Background: Slow-flow and no-reflow phenomenon which occurred frequently during primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) caused unfavorable prognostic outcomes. Currently, no effectively therapeutic strategy to prevent this phenomenon. Objectives/Design: To evaluate the efficacy and safety of intra-Coronary Administration of Tacrolimus prior to firstballoon inflation, a pilot study was performed. Methods/Results of Pilot Study: Twenty-nine STEMI patients (group 1) were first prospectively administered tacrolimus (2.5 mg intra-coronary slow injection using thrombuster) prior to first-balloon inflation. A historical-control group (group 2) was chosen from fifty-two consecutive patients undergoing primary PCI just prior to the pilot study. Age, gender, CAD-risk factors, peak CK-BM, and baseline left-ventricular performance were not different between groups 1 and 2 (all p>0.1). Chest pain onset-to-door and door-to-balloon times, mean Killip score upon presentation, number of multi-vessel disease, pre-PCI TIMI flow, and 30-day death were similar between these two groups (all p>0.1). The incidences of advanced CHF (≥ NYHA 3) and pulmonary edema were higher in group 2 than in group 1, whereas the incidence of anterior-wall infarction, final TIMI-3 flow and 90 minute ST-segment-resolution rate showed an opposite pattern of advanced CHF between these two groups. The incidence of myocardial blushing grade was significantly higher in group 2 than in group 1 (p=0.034). Conclusion: Tacrolimus therapy shows promise as a safe and effective therapeutic agent for STEMI. The positive preliminary outcomes from this pilot study suggests randomized-controlled trials are now required to evaluate the effectiveness and safety of Tacrolimus for STEMI patients. (clinical trials no: ISRCTN38455499).