LONG-TERM FOLLOW-UP OF PATIENTS WITH IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS AND MILD, MODERATE, OR SEVERE IMPAIRMENT OF LEFT-VENTRICULAR FUNCTION

Objective-To determine whether patients with life threatening ventricu lar tachyarrhythmias, impaired left ventricular function, and severe h eart failure will benefit from implantable cardioverter-defibrillator (ICD) treatment. Design-410 patients were followed up after ICD implan t. Left ventricular function was assessed by the New York Heart Associ ation (NYHA) functional class of heart failure: 50 patients (12%) were in NYHA I-II, 151 (37%) in NYHA II, 117 (29%) in NYHA II-III, and 92 (22%) in NYHA III. Epicardial ICD implantation was performed in 209 pa tients (51%) and 201 patients (49%) received non-thoracotomy ICDs. Res ults-Perioperatively, 12 patients (3%) died, more often after epicardi al ICD implant (11/209 patients, 5%) than after transvenous implant (1 /201 patients, < 1%) (P < 0.05). During a mean (SD) follow up of 28 (2 4) months (range < 1 to 114 months), 90 patients (23%) died: nine (2%) died from sudden arrhythmia; five (1%) also died suddenly but probabl y not from arrhythmic causes; 55 (14%) died from cardiac causes (conge stive heart failure, myocardial reinfarction); 21 (5%) died from non-c ardiac causes. The three year, five year, and seven year survival was 92-96% for arrhythmic mortality in NYHA class I, II, and III, compared to a three year survival of 94% and a five year and seven year surviv al of 84% for patients in NYHA class II-III. 338 patients (82%) receiv ed ICD shocks (21 (SD 43) shocks per patient); patients in NYHA class II (83%), class II-III (84%), and class III (90%) received ICD dischar ges more often than those in class I-II (64%) (P < 0.05). The mean (SD ) time interval between ICD implant and the first ICD shock was shorte r in NYHA class II (16 (17) months), class II-III (19 (27) months), an d class III (16 (19) months) than in class 0-I (22 (24) months) (P < 0 .05). Conclusions-Patients with mild, moderate, and severe left ventri cular dysfunction benefit from ICD treatment and these patients surviv e for a considerable time after the first shock. Survival is influence d by the degree of left ventricular dysfunction; aggressive treatment of heart failure is necessary as well as ICD therapy.