Background: Current guidelines do not suggest an age cut-off value for primary prophylactic ICD implantation. However, in recent years, the benefit of ICD implantation for elderly and very old patients has been questioned. In the present study, we aimed to analyse the outcome of patients with primary prophylactic ICD implantation in different age groups.

Methods: In this study, we included all patients who received an ICD (or CRT-ICD) implantation for primary prophylactic indication in our hospital from 2011 to 2020. Primary endpoints of the study were 1) death from any cause and 2) appropriate ICD therapy (ATP/shock). A benefit of ICD therapy was defined as appropriate ICD therapy before death from any cause/ or survival. No benefit of ICD therapy was defined as death of any cause without prior appropriate ICD therapy. A neutral outcome was present in surviving patients without ICD therapy. For follow-up, analysis of outpatient ICD controls and telephone contact with patients were performed.

Results: A total of 323 patients received an ICD for primary prophylactic indication during the study period. Ischemic cardiomyopathy was present in 164 patients (51%) and non-ischemic cardiomyopathy in 159 patients (49%). At the time of implantation, 21 patients (6.5%) were older than 80 years, 82 patients were older than 75 years (23%), 142 patients were older than 70 years (44%), and 197 patients (61%) were older than 65 years. The mean follow-up covered a period of 4.2 ± 3.0 years. Overall, 72 patients (22%) died without prior appropriate ICD therapy during this period (defined as no benefit) while 59 patients (18%) received appropriate ICD therapy during this period (defined as benefit). There was a significant difference in overall survival of patients greater or less than 75 years (Figure 1 A), but not in survival free from appropriate ICD therapy (Figure 1 B). With increasing age, the proportion of patients with benefit from ICD implantation decreased, whereas the mortality rates increased (Figure 2). There were no patients in the group of patients older than 80 years with a benefit of ICD therapy.

Conclusion: In our analysis of patients with primary prophylactic ICD implantation, there is a decreasing benefit of ICD therapy with increasing age. Our results suggest that the indication of primary prophylactic ICD in elderly and very old patients should be critically assessed.