Sex Differences in the Risk of First and Recurrent Ventricular Tachyarrhythmias Among Patients Receiving an Implantable Cardioverter-Defibrillator for Primary Prevention

Abstract

Key Points Question Is the risk of ventricular tachyarrhythmia similar between women and men with an implantable cardioverter-defibrillator for primary prevention? Findings In this cohort study of 4506 patients with an implantable cardioverter-defibrillator, women and patients with nonischemic cardiomyopathy displayed a significantly lower risk of first and recurrent life-threatening ventricular tachyarrhythmia events than men. In both cardiomyopathy types, risk of ventricular tachyarrhythmia remained significantly higher than risk of death without prior ventricular tachyarrhythmia for women and men, indicating a potential benefit of a primary prevention implantable cardioverter-defibrillator regardless of sex. Meaning Findings suggest that risk of ventricular tachyarrhythmia differs between men and women and by underlying cardiomyopathy, indicating a need for sex-specific risk assessment for primary prevention cardioverter-defibrillator implantation.

Arrhythmic Risk in Male and Female Patients With Heart Failure—Same but Different

“…One of the proposed reasons for this sex difference was the higher proportion of female patients with nonischemic cardiomyopathy. Saxena et al demonstrate that although the risk reduction for VTA was reduced to a greater extent in patients with nonischemic cardiomyopathy (HR, 0.50; 95% CI, 0.38-0.66), it also could be observed in patients with ischemic cardiomyopathy (HR, 0.73; 95% CI, 0.56-0.95) ( P = .03 for interaction). This indicates that other sex-specific differences must play a role.…”

“…6,7 Sex-specific risk stratification will undoubtedly play an increasing role in the quest to provide patients at highest risk for SCD with costly defibrillator therapy. The work by Saxena et al 3 underlines once more that there are important differences in cardiovascular outcomes between men and women and that the underrepresentation of women in randomized controlled trials is a problem that needs to be taken into account.…”

“…Saxena and colleagues from the Multicenter Automatic Defibrillator Implantation Trial (MADIT) study group help to fill this gap by reporting the sex-specific outcomes in the aggregate data of 4 landmark primary prevention ICD trials. Their cohort study retrospectively analyzed the data of 4506 patients, 1075 (24%) thereof being women.…”

“…The use of CRT along with an ICD in only some patients already made the interpretation of the DANISH trial complex, in which no survival benefit by the use of a primary prevention ICD could be observed in a population with nonischemic heart failure . In the MADIT cohort, significantly more women received a CRTD. However, the authors could not find a difference in the reduction of the primary end point in women between those who received only an ICD and those who carried a CRTD.…”

Do we need sex-specific guidelines?

“…Unfortunately, the registry is unable to provide information on occurrence of ICD shock delivery or VT/VF events. It would be challenging comparing real-world shock events with the recently published sub-study of all four MADIT-trials [2] . With only 24% females enrolled in this study, women had more non-ischemic cardiomyopathies (NICM), had significantly lower risk of sustained VT/VF events and less appropriate ICD shocks than men during a 3-year follow-up period.…”