Author + information
- Sanket S. Dhruva, MD∗ ( and )
- Rita F. Redberg, MD, MSc
- ↵∗Robert Wood Johnson Foundation Clinical Scholars Program, Yale School of Medicine, Cardiology, VA Connecticut Healthcare System, 333 Cedar Street, SHM I-456, Box 208088, New Haven, Connecticut 06520
We read with great interest the recent review by Lewis and Gold (1) in the Journal on the safety and efficacy of subcutaneous implantable cardioverter-defibrillators (S-ICDs), in which the authors conclude that S-ICDs are noninferior to traditional ICDs. However, there continues to be a lack of adequate numbers of women in S-ICD studies, and none of the 8 papers discussed in this review examined safety or efficacy by sex.
The S-ICD trials summarized in Table 1 in Lewis and Gold (1) have study populations ranging from 70% to 80% men. The underrepresentation of women mirrors women’s low representation in cardiovascular device trials (2), including pivotal primary prevention trials of traditional transvenous ICDs (3). Underenrollment of women in S-ICD studies continues this unfortunate trend and leaves patients and providers with an incomplete understanding of the device’s benefits and risks (4).
In all but 2 S-ICD studies reviewed by Drs. Lewis and Gold (1), primary prevention was the dominant indication for S-ICD implantation. However, it remains unclear whether women benefit from ICDs for primary prevention because their risk and mechanisms for sudden cardiac death differ from those of men. A meta-analysis of landmark trials showed negative results (3), whereas a more recent study with propensity-matched patients suggested that women do gain a mortality benefit (5).
Although the evidence base for S-ICDs is growing, it is still unfinished. Given the underrepresentation of women in S-ICD studies and the inconsistent data on benefits of ICDs for primary prevention in women, there is an urgent need to increase the enrollment of women and consider a female-only study of the S-ICD. Further, sex-specific analyses of outcomes should be required in future reports of the EFFORTLESS (Boston Scientific Post Market S-ICD) registry.
Please note: Dr. Redberg is a member of the Food and Drug Administration Circulatory System Devices Panel and the California Technology Assessment Forum. Dr. Dhruva has reported that he has no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
- Lewis G.F.,
- Gold M.R.
- Dhruva S.S.,
- Bero L.A.,
- Redberg R.F.
- Zeitler E.P.,
- Hellkamp A.S.,
- Schulte P.J.,
- et al.