Measurement of troponin T to detect cardioprotective effect of trimetazidine during coronary artery bypass grafting

Background. The aim of the present study was to evaluate potential myocardial protection by trimetazidine by measurement of the cardiac marker protein troponin T (TnT) during coronary bypass operations. Methods. We conducted a double-blind, placebo-controlled study on 30 randomized patients who had aorta-coronary artery bypass operations. The TMZ group was composed of 15 patients and the placebo group of 15 patients in New York Heart Association class III or IV. Pretreatment was started 3 weeks preoperatively with trimetazidine (60 mg orally per day) or the placebo. In the trimetazidine TMZ group, there were 2 women and 13 men with a mean age of 57.1 +/- 2.2 years and mean cross-clamp time of 44 +/- 1.8 minutes. In the placebo group, there were 5 women and 10 men with a mean age of 58.4 +/- 1.2 years and a mean cross-clamp time of 42 +/- 2.4 minutes. Serial blood samples were collected before and after the operation, and serum concentrations of cardiac TnT were measured. Results. The preoperative serum concentration of TnT was 0 to 0.39 ng/mL in all patients. The mean TnT levels were measured 5 minutes after completion of cardiopulmonary bypass (1.5 +/- 0.3 ng/mL) and 12 (1.4 +/- 0.1 ng/mL), 24 (0.9 +/- 0.1 ng/mL), and 48 hours postoperatively (0.1 +/- 0.1 ng/mL) in the trimetazidine group. Troponin T levels in the placebo group measured at the same time periods were 4.4 +/- 0.4, 4.8 +/- 0.7, 2.8 +/- 0.4, and 0.7 +/- 0.1 ng/mL. In the trimetazidine group, TnT levels were significantly less than those of the placebo group (p < 0.001). The levels of TnT were tested by creatine kinase-MB levels of both groups. Mean cardiac index was evaluated in all patients preoperatively and postoperatively. There was no significant difference in perioperative hemodynamics (blood pressure and cardiac index) between groups. Conclusions. These results obtained by measurement of cardiac TnT suggested that pretreatment with trimetazidine reduces ischemic-reperfusion damage during coronary bypass operations but did not affect postoperative hemodynamics. (C) 1999 by The Society of Thoracic Surgeons.