Comparison of efficacy of automatic implantable cardioverter defibrillator in patients older and younger than 65 years of age.
PURPOSE: The efficacy of the automatic implantable cardioverter defibrillator (AICD) was compared in elderly patients and younger patients with life-threatening ventricular tachyarrhythmias. Clinical characteristics, surgical complications, and long-term survival rates were compared between the two age groups. PATIENTS AND METHODS: A retrospective study was conducted of 54 elderly patients (greater than 65 years) and 79 younger patients (less than 65 years) who had had AICDs implanted for recurrent symptomatic ventricular tachycardia and/or ventricular fibrillation. RESULTS: In 85% of elderly patients and 78% of younger patients, coronary artery disease was the underlying disease (NS). The mean left ventricular ejection fraction was 31.4 +/- 14.3% in the elderly patients and 35.7 +/- 17.6% in the younger patients (NS). Concomitant myocardial revascularization was performed in 37% of elderly patients and 29% of younger patients (NS); however, only 4% of elderly patients had concomitant left ventricular resection or cryoablation, compared with 15% of younger patients (p less than 0.001). Two patients in each age group died perioperatively (4% versus 3%, NS), and no significant difference in surgical morbidity or length of hospital stay following AICD implantation was noted between the age groups. In conjunction with AICD, elderly patients more commonly received antiarrhythmic drugs, with 54% of elderly patients taking amiodarone at the time of hospital discharge compared with 29% of the younger patients (p less than 0.008). In contrast, beta-blockers were more commonly used in younger patients (16% versus 2%, p less than 0.03). At a mean follow-up of 25 months, 11 (20%) elderly patients and 16 (20%) younger patients had died. Six deaths in elderly patients and five deaths in younger patients were classified as arrhythmic deaths (NS); however, only one younger patient and three elderly patients died suddenly (NS). Calculated survival curves demonstrated similar survival rates in the two age groups with approximately 90%, 87%, and 80% of the patients alive at 1, 2, and 3 years, respectively. Theoretic survival curves calculated from appropriate AICD shocks demonstrated significantly lower survival compared with actual survival. CONCLUSION: It is concluded that AICD is a very effective treatment for life-threatening ventricular tachyarrhythmias, and this benefit applies to elderly patients as well as younger patients.