Efficacy and Safety of Implantable Cardioverter Defibrillator (ICD) Implantation in the Elderly (the I-70 Study)

BACKGROUND There is conflicting fl icting evidence on the efficacy fi cacy of primary prevention implantable cardioverter-defibrillator fi brillator (ICD) implantation in the elderly. OBJECTIVE The purpose of this study was to determine the efficacy fi cacy and safety of ICD implantation in patients 70 years and older. METHODS Patients (n = 167) aged 70 years or older and eligible for ICD implantation were randomly assigned (1:1) to receive either optimal medical therapy (OMT) (n = 85) or OMT plus ICD (n = 82). RESULTS Of the 167 participants (mean age 76.4 years; 165 men), 144 completed the study protocol according to their assigned treatment. Average participant follow-up was 31.5 months. Mortality was similar between the 2 groups: 27 deaths in OMT vs 26 death in ICD (unadjusted hazard ratio 0.92; 95% confidence fi dence interval 0.53-1.57), but there was a trend favoring the ICD over the fi rst 36 months of follow-up. Rates of sudden death (7 vs 5; P = .81) and all-cause hospitalization (2.65 events per participant in OMT vs 3.09 in ICD; P = .31) were not statistically significantly fi cantly different. Eleven participants randomized to ICD received appropriate therapy. Five participants received an inappropriate therapy that included at least 1 ICD shock. CONCLUSION The study did not recruit to target sample size, and accumulated data did not show benefit fi t of ICD therapy in patients 70 years or older. Future studies similar in design might be feasible but will need to contend with patient treatment preference given the large number of patients who do not want an ICD implanted. Further research is needed to determine whether the ICD is effective in prolife device candidates.