This retrospective study was performed to evaluate the clinical and angiographic characteristics and the in-hospital complications after failed percutaneous coronary angioplasty (PTCA) that necessitates coronary artery bypass graft surgery (CABG). The study population consisted of 123 patients from January 1990 to December 1992. The failed PTCA was secondary to an acute occlusion of the dilated but dissected vessel in 36.5% of the study population. 43 patients (35%) had an emergency CABG due to hemodynamic instability and a large area of myocardium at risk for infarction. 93% of these patients had an acute closure of the dissected vessel. 19 patients (15%) were operated 24 hours after failed PTCA and 61 patients (49.5%) electively 3.8 +/- 1.1 months after PTCA. Mean time interval from the acute occlusion up to the establishment of the extracorporeal circulation (ischemic interval) was 70 +/- 9 min. in patients from our cardiological department and 136 +/- 14 min. in patients from external departments. Analysis of the surgical data revealed that neither a patient of the emergency group nor of the elective group needed the intra-aortic balloon pump. Overall 2.3 +/- 0.8 bypass grafts were placed, with increased use of the internal mammarian artery in the elective (57%) versus the emergency group (17%). Postoperative peak values of CK and CK-MB were significantly higher in the emergency group as compared to the patients operated 24 hours and electively after failed PTCA. Patients with an ischemic interval up to 70 min. had considerably lower CK and CK-MB values compared to patients with longer ischemic intervals.(ABSTRACT TRUNCATED AT 250 WORDS)