EFFICACY OF THE IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR IN THE ELDERLY

Objectives. We sought to assess the effect of advanced age on the outc ome of patients with an implantable cardioverter-defibrillator (ICD). Background ICDs are effective in preventing sudden cardiac death in su sceptible patients, but their beneficial effect on survival is attenua ted by the high rate of nonsudden cardiac death in those treated. Alth ough advanced age is an important variable in determining cardiovascul ar mortality, its impact on the outcome of patients with an ICD has be en inadequately studied. Methods. We performed multivariate analysis o f a data base consisting of 769 consecutive patients with an ICD. Seve nty-four patients greater than or equal to 75 years old at ICD implant ation (Group 1) were compared with the remaining 695 patients (Group 2 ). Results. The two groups were similar in clinical presentation, left ventricular function and gender distribution. The mean follow-up time was 29 and 42 months, respectively, for patients in Group 1 and Group 2, Actuarial survival at 4 years was 57% in Group 1 versus 78% in Gro up 2 (p = 0.0001). This difference was primarily due to a higher rate of nonsudden cardiac death in Group 1. On multivariate analysis, age g reater than or equal to 75 years, New York Heart Association functiona l class III, left ventricular ejection fraction <30% and appropriate s hocks during follow-up were independently associated with increased mo rtality (odds ratio 3.56, 1.8, 1.6 and 1.39, respectively). Conclusion s. Among patients with similar functional class and ejection fraction, the mortality risk is increased threefold in those greater than or eq ual to 75 years old at the time of ICD implantation. Extrapolation of results from younger patients is likely to overestimate ICD benefit in the elderly. (C) 1997 by the American College of Cardiology.