CAPTOPRIL IN CARDIOPLEGIA AND REPERFUSION - PROTECTIVE EFFECTS ON THEISCHEMIC HEART

Background. Previous studies have shown that longterm treatment with t he angiotensin-converting enzyme inhibitor captopril attenuates left v entricular dilatation and improves survival after extensive myocardial infarction. However, there is only sparse evidence of the immediate e ffects of the drug on hearts undergoing global ischemia and reperfusio n. The purpose of this study was to investigate the direct effect of c aptopril, given in cardioplegia or after ischemia, on the functional r ecovery of the reperfused myocardium. Methods. Isolated rat hearts und ergoing warm cardioplegic arrest followed by 1 hour of global ischemia and 30 minutes of reperfusion were studied using the modified Langend orff model. Results. After ischemia, hearts receiving captopril (360 m u mol/L) either in the cardioplegic solution (n = 9) or during reperfu sion (n = 9) developed higher pressure (p < 0.001), greater first deri vative of the rise in left ventricular pressure (p < 0.01 and p < 0.00 1, respectively), greater first derivative of the fall in left ventric ular pressure (p < 0.001 and p < 0.002), higher pressure-time integral (p < 0.001), greater coronary now (p < 0.001), and higher oxygen cons umption values (p < 0.001 and p < 0.003) compared with the control gro up (n = 9). Hearts receiving captopril both in the cardioplegia and du ring reperfusion (n = 9) had the best recovery of all three groups and lower levels of creatine kinase (47.8 +/- 5.9 U/L versus 73.3 +/- 5.6 U/L; p < 0.01) compared with the control group. Conclusions. Captopri l given in cardioplegia and in reperfusion has a favorable, protective , and additive effect on the recovery of isolated rat hearts undergoin g global ischemia and reperfusion; hemodynamic performance improves, c oronary how and oxygen consumption increase, and myocardial damage dec reases. (C) 1997 by The Society of Thoracic Surgeons.