OPERATIVE MORTALITY WITH IMPLANTATION OF THE AUTOMATIC CARDIOVERTER-DEFIBRILLATOR

Operative mortality was studied in 939 consecutive patients undergoing initial implantation of an automatic implantable cardioverter-defibrillator (AICD(TM)) at 15 hospitals. Twenty-nine (3.1%) patients died during the first 30 days after surgery. Among patients who survived beyond the first 30 postoperative days, ejection fraction data were available in 219; compared with the mortality group, these survivors had a significantly higher ejection fraction (34 +/- 15 vs 26 +/- 10%, respectively, p < 0.001), despite similar age, sex, underlying heart disease, type of presenting arrhythmia and prevalence of concomitant surgery. The causes of perioperative death were sudden in 7 (24%), tachyarrhythmic/nonsudden in 5 (17%), cardiac nonarrhythmic in 9 (31%), and noncardiac in 8 (28%). Twenty-four (83%) of the deaths occurred before hospital discharge, and in all 9 instances of in-hospital sudden and tachyarrhythmic/nonsudden death, the initial recorded rhythm was sustained ventricular tachycardia or fibrillation; in 5 (56%) of these 9 patients the AICD had been in a deactivated state since implantation. Other possible contributory factors in the 12 sudden or tachyarrhythmic/nonsudden deaths included acute myocardial ischemia or infarction in 2 (17%), and "device proarrhythmia" in 3 (25%) that were AICD-related in 2 and secondary to an antitachycardia pacemaker in another; defibrillation threshold testing was not performed in 3 patients (1 of whom had terminal ventricular fibrillation). Thus, in this multicenter experience with thoracotomy requiring AICD implantation, operative (30-day) mortality was 3.1% and correlated inversely with left ventricular ejection fraction. Further studies are needed to explore the potential role of management practices in the occurrence of sudden or tachyarrhythmic/nonsudden death, which accounted for 41% of all postoperative fatalities in this AICD implantation series.