Implantable cardioverter-defibrillator therapies in primary prevention are not decreased in a contemporary cohort: insights from long-term follow-up

Abstract Background Among patients with heart failure with reduced ejection fraction (HFrEF) a significant proportion of deaths occur due to ventricular tachyarrhythmias. Implantable cardioverter defibrillators (ICD) are recommended in primary prevention to reduce sudden death and all-cause mortality in patients with symptomatic HFrEF with left ventricular ejection fraction (LVEF) ≤35%, after at least three months of guideline-directed medical therapy (GDMT). However, the trials responsible for the inclusion of this recommendation in the guidelines predate the use of angiotensin receptor-neprilysin inhibitors (ARNIs) and sodium–glucose co-transporter 2 inhibitors (SGLT2i). Whether the benefit on survival of implanting an ICD after GDMT in these patients with the contemporary available medication is maintained is not known. Methods Consecutive patients with HFrEF, symptomatic NYHA class II-III and with LVEF ≤35% after 3 months of GDMT submitted to ICD implantation for primary prevention at our center between 2015 and 2022 were included. Baseline characteristics and incident ICD therapies (antitachycardia pacing and shocks) were recorded during follow-up. We retrospectively analyzed the time to ICD therapies in a historical cohort (group 1) as compared with a contemporary cohort after the generalization of treatment with ARNI and SGLT2 inhibitors (group 2). A Cox regression survival model was used to analyze the effect on incident ICD therapies. Results 289 patients (82.4% males, age 62±11.3 [between 50 and 73 years]) were included; 148 (51.2%) in group 1 (implantation of ICD before ARNI and SGLT2 inhibitors use) and 141 (48.8%) in group 2 (implantation of ICD in the era of contemporary pharmacotherapy for HFrEF). Patients in group 2 had longer QRS duration and were more likely in NYHA class I. The mean follow-up duration was 51.3±28.8 months. The number of ICD therapies at one year did not significantly differ between the groups (odds ratio [OR] 2.24; 95% confidence interval [CI] 0.93-5.41, p value = 0.073). After Cox regression analysis, ICD recipients in the contemporary OMT cohort had a higher risk of ICD therapies during a long-term follow-up period (hazard ratio [HR] 2.48; 95% confidence interval [CI] 1.011-6.085, p value 0.047). Conclusion In patients with HFrEF submitted to ICD implantation for primary prevention after OMT, the incidence of ICD therapies in a contemporary cohort was similar at 1 year and higher at long-term follow-up. Our results suggest that the benefit of implanting an ICD in patients with HFrEF and LVEF ≤35% is maintained in the current era of GDMT including ARNI and SGLT2i.Kaplan-Meier free from ICD therapies