For individuals diagnosed with heart failure (HF) with reduced ejection fraction (HFrEF), a condition where the heart struggles to effectively pump blood, current guidelines recommend the use of implantable cardioverter-defibrillators (ICDs) to mitigate the risk of sudden cardiac death (SCD). While there is strong evidence supporting ICDs for ischemic HF (caused by reduced blood flow to the heart, typically from narrowing arteries), their benefit is less clear for non-ischemic HF (arising from other causes like genetic conditions, infections, or high blood pressure).
Drawing on data from the VICTORIA trial, a recent publication in the European Journal of Heart Failure investigated the role of pre-existing ICDs in HF patients. Researchers assessed the impact of baseline ICD use on mortality, accounting for both the underlying cause of HF and vericiguat treatment effect. This study also explored whether age and sex influenced these associations, given prior research suggesting a diminished ICD benefit in women (especially those with non-ischemic HF) and older individuals.
The study analyzed over 5,000 VICTORIA participants with HFrEF with a recent worsening HF event. These individuals were categorized by the cause of their HF (53.6% ischemic; 46.4% non-ischemic) and whether they had an ICD at the study’s start (27.8%). Using a sophisticated statistical method called propensity-score adjustment, the researchers then assessed how having an ICD affected their risk of SCD, death from any cardiovascular cause (including SCD), and death from all causes.
Over a median period of 10.8 months, the study found ICDs were linked to an overall reduction in SCD, though they showed no notable impact on overall cardiovascular or all-cause mortality. Interestingly, the cause of HF (whether ischemic or non-ischemic) did not alter the ICD’s effect on SCD. Despite lower ICD use in women, those with ischemic HF experienced a substantial reduction in SCD risk with an ICD. The researchers also observed that atrial fibrillation (an irregular heart rhythm) appeared to negate the ICD’s benefit for preventing SCD. Ultimately, these findings underscore the critical need for future research to precisely identify which HFrEF patients truly benefit from ICD implantation, with an evaluation that extends beyond solely reducing SCD to encompass broader outcomes.
This research, conducted on behalf of the VICTORIA Study Group, was led by Dr. Pishoy Gouda and co-authored by fellow CVC members Drs. Paul Armstrong, Wendimagegn Alemayehu, Justin Ezekowitz, Cynthia Westerhout, Haran Yogasundaram, and Roopinder Sandhu. Additional collaborators were Drs. Adriaan Voors (University of Groningen), Carolyn Lam (University of Singapore), Burkert Pieske (University of Rostock), and Javed Butler (Baylor University).
