Coronary bypass grafting after failed elective and failed emergent percutaneous angioplasty. Relative risks of emergent surgical intervention.

Emergency coronary artery bypass grafting after failed elective percutaneous transluminal coronary angioplasty can be performed with acceptable complication rates. Recently, however, a new class of patients with unsuccessful angioplasty has evolved with the use of thrombolytic therapy and emergent angioplasty as treatment for developing acute myocardial infarction. The efficacy of surgical intervention after failure of angioplasty in this setting has not been demonstrated. This report compares the results of coronary bypass done emergently after either failed elective or failed emergent angioplasty. Between March 1984 and September 1986; 1350 angioplasty procedures were performed at our institution, 393 for acute myocardial infarction. Of the 111 patients who came to operation, 42 had had unsuccessful elective angioplasty and 69 unsuccessful angioplasty done in the clinical setting of an evolving acute myocardial infarction detected by electrocardiographic criteria. Twenty-one of the 42 patients having unsuccessful elective angioplasty (group I) and 32 of the 69 with unsuccessful emergent angioplasty (group II) underwent emergency coronary artery bypass grafting. A retrospective nonparametric statistical comparison of the two groups was performed. Age, preoperative ejection fraction, distribution of vessels undergoing angioplasty, and number of vessels bypassed were not statistically different. All group II patients received thrombolytic therapy, and a reperfusion catheter was used in over half the patients in each group. Three group I and six group II patients required a preoperative balloon pump, and half the patients in each group required postoperative inotropic support. One patient in group I (4.7%) and two patients in group II (6.2%) died (no significant difference). Only five patients in group I (23.8%) and 11 in group II (34.3%) had enzymatic and electrocardiographic evidence of an acute myocardial infarction at discharge. Six patients in group II (15.6%) required reexploration for bleeding, versus none in group I (p = 0.04). Nonhemorrhagic complication rates, mean in-patient and acute care days, total hospital charges, and blood product utilization rates were not statistically different. These data indicate that emergency coronary artery bypass grafting can be performed when necessary in the setting of failed emergent percutaneous transluminal coronary angioplasty with results comparable to coronary bypass after failed elective angioplasty.

Duke Scholars

Author Lawrence H. Muhlbaier Biostatistics & Bioinformatics, Division of Biostatistics