Abstract

Background: There is limited data regarding the effectiveness of implantable cardioverter defibrillators (ICD) treatment among diverse patient populations. Therefore, this systematic review aims to evaluate cardiovascular outcomes by age, sex, and race among patients who received an ICD.

Methods: Electronic databases (Pubmed, Emcare, Embase, Medline (Ovid), and CINAHL were searched for randomized control trials (RCTs) that evaluated the use of an ICD compared with a control group. Studies were excluded if they were non-RCT, non-English, duplicate publications, animal studies, or if the patient population was <18 years of age. Data were analyzed for all-cause death, 3-point major cardiovascular adverse outcomes, and heart failure hospitalization (HFH) by age, sex, and race.

Results: 7125 patients were included from five RCTs with 3260 patients in the ICD group and 3865 patients in the control group. The composite outcome of all-cause death or HFH, all-cause death, HFH, and cardiovascular (CV) death in women were lower compared to men within the ICD group, however this was not significant (OR 0.834, 95% CI 0.488-1.425, P=0.51; OR 0.807, 95% CI 0.516-1.262, P=0.35; OR 0.950, 95% CI 0.508-1.776, P=0.87; OR 0.981, 95% CI 0.466-2.066, P=0.96). Cardiovascular death (not including arrhythmic death) in women was higher compared to men within the ICD group, although this was not significant (OR 1.781, 95% CI 0.291-10.920, P=0.53). Furthermore, all-cause death was higher in black patients compared to white patients within the ICD group, but this was not significant (OR 1.201, 95% CI 0.524-2.750, P=0.67).  Age-related data were not reported in these RCTs.

Conclusion: While sex and race differences in outcomes were not significant, future research is needed to understand the relationship between these factors and outcomes among patients who received an ICD.