Our results with surgical revascularization for evolving myocardial infarction in 30 patients are analyzed. There were 25 men and 5 women (mean age 55 +/- 10 years), most with unstable angina (80%), which sustained an acute myocardial infarction secondary to either a severe stenosis (23%) or a complete obstruction (77%) of a mayor coronary artery during a diagnostic coronarography (27%) or a percutaneous transluminal coronary angioplasty (73%). The most frequently involved vessels were the left anterior descending and right coronary arteries (11 cases), followed by the left main stem (5 cases) and the circumflex artery (3 cases). Nineteen patients (group I) developed electrocardiographic and/or enzymatic evidence of established myocardial necrosis despite early reperfusion, whereas 11 patients did not (group II). These groups were compared according to different clinical, angiographic, hemodynamic, and operative variables. Group I patients had a more recent disease and a better segmentary contraction. The same variables were compared between the 5 patients with early cardiac death (group III) and the remainder 25 (group IV). Refractory cardiac arrest, jeopardized myocardial mass and coronary perfusion indexes after the infarction-related complication, all were more desfavorable in group III. The ischemic interval between infarction onset and reperfusion was not different between the groups. The potential of surgery for myocardial salvage in the setting of evolving necrosis is emphasized as well as the influence of the magnitude of involved myocardium and its clinical repercussion on early mortality.