Sex differences in implantable cardiac defibrillators in patients with severe left ventricular dysfunction

Bacground: Prior studies demonstrated that women (W) eligible for a primary prevention implantable cardiac defibrillator (ICD) are less likely to receive one as compared to men (M).

Aim: To assess the rates of ICD implantations among W and M with left ventricular (LV) ejection fraction (EF) <35% and its outcome.

Methods: Retrospective analyses of ICDs implantations among patients with echocardiographic LVEF<35% between 1/1/2005-1/10/2019 in our center were performed.

Results: The study included 2441 patients with LVEF<35%, 572(23%) W. As compared to M, W were older (71+15 vs 69+14 yrs, respectively p=0.001), had similar frequency of diabetes (30% vs 33% % respectively), more hypertension (61% vs 53% respectively, p=0.008), less ischemic heart disease (IHD) (49% vs 67% respectively, p<0.0001), similar congestive heart failure (CHF) (38% vs 35% respectively), more renal failure (18% vs 11% respectively ,p=0.002). ICD implantation was performed in 76 (13%) W as compared to 476 (26%) M, p<0.0001

A multivariate logistic regression model including clinical characteristics revealed that female sex was independently associated with lower rate of ICD implantation, OR=0.44;95%CI [0.32-0.61];p<0.0001

During a median follow up of 578[89-1554] days, 280 W and 874 M died, 54% of W vs 51% of M without ICD, and 32% vs 39% respectively with ICD.

Multivariable COX models revealed that after correction for clinical characteristics ICD implantation was independently associated with lower all-cause mortality rates for both W and M, HRs [95%Cis], p-values: 0.51[0.31-0.82]; 0.006 and:0.64[0.53-0.77] ; <0.0001, respectively. No association was found between gender and mortality, HR=1.06; 95%CI[0.89-1.26], p=0.5.

Conclusions: In our cohort W eligible for ICD implantation were less likely to receive it as compared to M. ICD implantation is a life-saving procedure and its use should be increased both in W and M, however, a special effort should be deployed to abolish sex-related gaps.