Do women benefit equally as men from the primary prevention implantable cardioverter-defibrillator?

Women traditionally have been and are still underrepresented in research in many important areas of cardiology, and guideline recommendations which also encompass women are mostly based on research conducted predominantly in men. However, there is plausible cause to believe that sex may have a potential influence on the benefit derived from the implantable cardioverter-defibrillators (ICD), alone or in association with cardiac resynchronization therapy. We assessed the possible relationship between sex and outcome with ICD implantation in the setting of primary prevention, by pooling the results of MUSTT, MADIT-II, DEFINITE, COMPANION, SCD-HeFT and DANISH trials in a meta-analysis. We pooled results for female and male patients separately. The results suggest that women as a group do not seem to obtain a significant survival benefit from the primary prevention ICD, contrary to men. This in turn may also have contributed to a relative underestimation of the ICD benefit among males when looking at the results in total. It is time for the medical and research communities to actively question the presumed overarching benefit of ICDs irrespective of sex and engage in systematic scientific efforts to definitively evaluate the value of this intervention in women.