SURGICAL REVASCULARIZATION IN PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION

This retrospective study was done to assess the results of emergency r evascularization in patients with acute myocardial infarction. In addi tion, the influence of the mode of reperfusion was investigated in ter ms of morbidity and mortality. Between January 1987 and May 1992, 75 c onsecutive patients with acute coronary occlusion (in 87 % PTCA-failur e) received one of two different reperfusion protocols during emergenc y aortocoronary bypass operation. In 36 patients, the reperfusate was normal blood given at systemic pressure (uncontrolled reperfusion); in 39 patients, the ischemic area was initially reperfused for 20 minute s with a blood cardioplegic solution (substrate-enriched, hyperosmolar , hypocalcemic, alkalotic, diltiazem-enriched) given at 37-degrees-C a nd at a perfusion pressure of 50 mmHg. Thereafter, the heart was kept in the beating empty state for 30 minutes before extra-corporeal circu lation was discontinued (controlled reperfusion). Regional contractili ty (echocardiography, radionuclide ventriculography), electrocardiogra m (ECG), release of creatine kinase and MB-isoenzyme of creatine kinas e as well as hospital mortality were assessed. Quantification of regio nal contractility was done with a scoring system from 0 (normokinesis) to 4 (dyskinesis). Data are expressed as mean +/- standard error of t he mean (SEM). Both groups were well matched for age, sex, and the dis tribution of the occluded artery. In the controlled reperfusion group, there was a higher incidence of additional significant stenosis (2.2 +/- 0.1 vs 1.7 +/- 0. 1) and cardiogenic shock (36 % vs 17 %). Further more, the interval between coronary occlusion and reperfusion was long er in the controlled reperfusion group (4.1 +/- 0.3 vs 3.3 +/- 0.3 hrs ; p > 0.05). Regional contractility returned to normal after controlle d reperfusion (score 0.8 +/- 0.2; normokinesis = 0, slight hypokinesis = 1). In contrast. regional contractility remained depressed severely after uncontrolled reperfusion with normal blood (score 1.5 0.3; p < 0.05). Enzyme release and ECG-changes were similar in both groups post operatively. While only 2 of 39 patients died in the controlled reperf usion group (5.1 %), mortality increased to 11.1 % (4/36) if normal bl ood is used as the primary reperfusate. Our data show, that the surgic al revascularization during acute myocardial infarction can be perform ed with acceptable mortality and morbidity rates. Further improvement of the results can be obtained if controlled regional reperfusion for the previously ischemic area is used.