Background: Secondary prophylactic ICD implantation to prevent sudden cardiac death is performed in all age groups. However, few data are available for secondary prophylaxis in elderly and very old patients, questioning the benefit of ICD therapy in patients older than 75 years. Therefore, in this study, we aimed to analyse the outcome of patients with secondary prophylactic ICD indication in different age groups.

Methods: In this study, all patients who received an ICD (or CRT-ICD) for secondary prophylactic indication in our hospital during 2011-2020 were included. 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 99 patients received an ICD for secondary prophylactic indication during the study period. In 65 patients (66%), the indication was survived sudden cardiac death with evidence of ventricular fibrillation, and in 34 patients (34%), evidence of sustained ventricular tachycardia. At the time of implantation, 14 patients (14%) were older than 80 years, 24 patients (24%) were older than 75 years, 40 patients (40%) were older than 70 years, 58 patients (59%) were older than 65 years, and 41 patients were younger than 65 years (41%). The mean follow-up covered a period of 4.2 ± 3.0 years. Overall, 12 patients (12%) died without prior appropriate ICD therapy during this time (defined as no benefit) while 30 patients (30%) received appropriate ICD therapy (defined as benefit). There was no difference in overall survival and survival free from appropriate ICD therapy between patients over or under 75 years of age (Figure 1). The proportion of patients with benefit from ICD therapy varied between 20-30% in the different age groups (figure 2).

Conclusion: In our analysis of patients with secondary prophylactic ICD implantation, there was a benefit of ICD therapy across all age groups. The group of patients older than 75 years and even older than 80 years also revealed a benefit of ICD therapy. Our study suggests that no patient should be denied secondary prophylactic ICD implantation because of age.