To evaluate the effects of temperature on myocardial and total body protection, we analyzed 129 consecutive patients who underwent coronary artery bypass grafting, valve replacement, or both, with continuous cardioplegia (Cp). The patients were assigned to three groups: group I (n = 37) normothermic cardiopulmonary bypass (CPB) (37 degrees C) and warm (37 degrees C) Cp, group II (n = 49) normothermic CPB and cold (4 degrees C) Cp and group III (n = 43) hypothermic (28 degrees C) CPB and cold Cp. Comparison of groups I and II showed similar serum levels of creatine kinase (CK) and its myocardial-specific isoenzyme on the first postoperative day, a similar rate of perioperative myocardial infarction, postoperative need for intra-aortic balloon pump, postoperative need for inotropic support and mortality. Comparison of groups I and III showed similar serum levels of CK, amylase, lactate dehydrogenase and creatinine on the first postoperative day, a similar complication rate and mortality rate. However, normothermic CPB resulted in a shorter bypass time (83 +/- 4 vs 98 +/- 7 min, P < 0.05) and interval until extubation (25.0 +/- 3.8 vs 40.3 +/- 7.4 h, P < 0.05). In conclusion, there are no differences concerning myocardial protection, however, warm CPB shortens the perfusion time and postoperative course.