Clinical effectiveness of CRT and ICD therapy in heart failure patients by racial/ethnic classification: insights from the IMPROVE HF registry

Background: Clinical trials have demonstrated benefit for cardiac resynchronization therapy (CRT) and implantable cardioverter-defibrillator (ICD) therapies in patients with heart failure with reduced ejection fraction (HFrEF); yet, questions have been raised with regard to the benefit of device therapy for minorities.

Objectives: The purpose of this study was to determine the clinical effectiveness of CRT and ICD therapies as a function of race/ethnicity in outpatients with HFrEF (ejection fraction ≤35%).

Methods: Data from IMPROVE HF (Registry to Improve the Use of Evidence-Based Heart Failure Therapies in the Outpatient Setting) were analyzed by device status and race/ethnicity among guideline-eligible patients for mortality at 24 months. Multivariate Generalized Estimating Equations analyses were conducted, adjusting for patient and practice characteristics.

Results: The ICD/cardiac resynchronization defibrillator (CRT-D)-eligible cohort (n = 7,748) included 3,391 (44%) non-Hispanic white, 719 (9%) non-Hispanic black, and 3,638 (47%) other racial/ethnic minorities or race-not-documented patients. The cardiac resynchronization pacemaker (CRT-P)/CRT-D-eligible cohort (n = 1,188) included 596 (50%) non-Hispanic white, 99 (8%) non-Hispanic black, and 493 (41%) other/not-documented patients. There was clinical benefit associated with ICD/CRT-D therapy (adjusted odds ratio: 0.64, 95% confidence interval: 0.52 to 0.79, p = 0.0002 for 24-month mortality), which was of similar proportion in white, black, and other minority/not-documented patients (device-race/ethnicity interaction p = 0.7861). For CRT-P/CRT-D therapy, there were also associated mortality benefits (adjusted odds ratio: 0.55, 95% confidence interval: 0.33 to 0.91, p = 0.0222), and the device-race/ethnicity interaction was not significant (p = 0.5413).

Conclusions: The use of guideline-directed CRT and ICD therapy was associated with reduced 24-month mortality without significant interaction by racial/ethnic group. Device therapies should be offered to eligible heart failure patients, without modification based on race/ethnicity.