Sex differences in the incidence of appropriate ventricular arrhythmias therapy in patients with ICD or CRT-D for primary prevention

Abstract Introduction – Patients with heart failure and reduced ejection fraction have a higher incidence of sustained ventricular arrythmias (VT/VF). Current guidelines recommend implantable cardioverter-defibrillators (ICD) or cardiac resynchronization therapy with Defibrillator (CRT-D) (depending on QRS width) implantation for primary prevention in patients with reduced left ventricular ejection fraction (LVEF ≤35%) after at least three months of optimal medical therapy. This study aimed to assess sex differences regarding appropriate device therapy in these population. Methods – Consecutive patients from January 2015 to July 2023 that were submitted to ICD or CRT-D implantation in primary prevention at a tertiary centre were included. Patients were divided into two groups according to sex category (female vs male). Groups were compared regarding comorbidities and therapeutic with chi-square test. A retrospective analysis regarding appropriate device therapy (ATP or shock) in the two groups was performed and then a Kaplan- Meier survival analysis to check for appropriate device therapy differences between the two groups. We also conducted a sub-group analysis regarding ischemic versus non-ischemic patients. Results - 378 patients (age 64,2±11,0 years; 22% female, 58,5% with ischemic heart disease) were included with a mean follow-up of 4.59 ± 2.4 years. There were no differences between groups regarding therapeutic with ACEi/ARB (64,2% vs 59,8%; p=0,473); ARNI (28,4% vs 34,2%; p= 0,352); beta-blocker (97,5% vs 93,8%; p=0, 268); SGLT2i (18,5% vs 18,6%; p=0,994) and mineralocorticoid antagonist (77,8% vs 79,5%; p=0,743). Regarding comorbidities, there were statistically significant differences on the prevalence of smoking (15,7% vs 28%; p=0,023), opposed to dyslipidaemia (53% vs 68%; p=0,11), hypertension (62,7% vs 71,1 %; p=0,141) and diabetes (28,9% vs 33%; p=0,482). There was an episode of sustained VT/VF in 91 patients (24,1%) during FU,15 female and 76 male (p=0,144). Kaplan-Meier survival curves were constructed to assess sex differences in arrhythmic event incidence, with statistical significance evaluated using the log-rank test. Regarding the overall population, no significant difference was observed (p=0,105). When performing a sub-group analysis according to ischemic vs non-ischemic patients, there was a significant difference in the non-ischemic group (p= 0,023) opposed to the ischemic group (p=0,980). Conclusion – In our cohort of ICD/CRT-D patients, there was no significant difference regarding appropriate device therapy between male and female gender. However, in non-ischemic patients, it appears that males have a higher incidence of VT/VF treated via the device.Kaplan Meyer