BASE-LINE CHARACTERISTICS OF PATIENTS IN THE CORONARY-ARTERY BYPASS GRAFT (CABG) PATCH TRIAL

Background Patients with left ventricular dysfunction who undergo coro nary artery bypass graft (CABG) surgery frequently have late sudden ca rdiac death. The CABG Patch Trial is a prospective, randomized, multic enter clinical trial that randomized patients at high risk at the comp letion of CABG surgery to implantation of an epicardial implantable ca rdioverter defibrillator (ICD) or to no antiarrhythmic treatment. The trial was designed to determine whether prophylactic implantation of a n ICD at the time of CABG surgery would result in a lower total mortal ity in long-term follow-up. Methods Patients undergoing CABG surgery w ere eligible for the trial if they were younger than 80 years, had a l eft ventricular ejection fraction less than 0.36, and had an abnormal signal averaged electrocardiogram. Patients with a history of sustaine d ventricular tachycardia or ventricular fibrillation were excluded fr om the trial. All patients were scheduled to undergo follow-up at 3-mo nth intervals until 42 months after surgery. Results Randomization of patients in the trial ended in February 1996. During the recruitment p eriod 71,855 patients were screened, 1,422 were eligible, 1,055 were e nrolled (signed consent forms), and 900 patients (76% of eligible pati ents) were randomized. The mean age of the 446 patients in the ICD gro up was 64 years versus 63 years for the 454 patients in the control gr oup. A total of 87% of the participants in the ICD group were men vers us 82% in the control group (p = NS). Most of the patients had a histo ry of hypertension (55%), smoking (78%), and hypercholesterolemia (54% ). Half of the patients had clinical heart failure, and the mean eject ion fraction for both patient groups was 0.27 +/- 0.06. No difference was seen in the history of myocardial infarction (83%), congestive hea rt failure (50%), or atrial (11%) or ventricular (17%) arrhythmias bet ween the two groups. Major clinical characteristics (age, sex, number of previous infarctions, incidence of heart failure, and mean left ven tricular ejection fraction) were almost identical to those found in an other ICD primary prevention trial, the Multicenter Automatic Defibril lator Implantation Trial (MADIT). Conclusions A high risk sample of pa tients was enrolled in The CABG Patch Trial, as shown by examination o f their baseline characteristics.