Are women worldwide under-treated with regard to cardiac resynchronization and sudden death prevention?

Implantable cardioverter defibrillators (ICDs) have been demonstrated to improve survival in patients with serious structural heart disease. Likewise, cardiac resynchronization therapy (CRT) has assumed an important role in the treatment of patients with symptomatic heart failure because of its demonstrated value in improving functional class, quality of life, exercise capacity, and survival. However, these clinical trials have all primarily enrolled Caucasian males, raising the question as to whether other important subgroups benefit in a comparable way. Women have lower rates of sudden cardiac death (SCD) compared to men, and event rates lag 10-20 years behind those in men. Among patients with known coronary artery disease, women have one-fourth the risk of SCD found in men. Women with heart failure tend to present at an older age than men, and women more often have heart failure with preserved systolic function, a group in whom prophylactic ICD therapy for the prevention of SCD has not been studied. Despite these differences, analysis of clinical trial results shows that women have similar outcomes with ICD and CRT therapy compared to men. There is a lower percentage of women among device therapy patients both in clinical trials and in practice for reasons that are not clear, but at least some of the difference is likely due to differences in age at presentation and co-morbidities. In fact, device therapy overall appears to be under-utilized in both men and women, when implantation rates are compared to the prevalence of heart failure in the population as a whole.