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Effectiveness of Cardiac Resynchronization Therapy with Defibrillator in At-Risk Black and White Cardiac Patients


  • Disclosures: The authors have no conflicts to disclose.

Address for correspondence: Ilan Goldenberg, M.D., Heart Research Follow-up Program, Box 653 University of Rochester Medical Center, Rochester, New York 14642. Fax: 585-273-5283; E-mail:



There are limited data regarding racial differences in response to cardiac resynchronization therapy with defibrillator (CRT-D).


We assessed the effectiveness of CRT-D, as compared to implantable cardioverter defibrillator (ICD) therapy alone, in reducing the risk of heart failure (HF) or death and changes in cardiac volumes among 1638 (90%) white patients and 143 (8%) black patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT).


Enrolled black patients displayed a higher frequency of diabetes mellitus, treated hypertension, higher creatinine levels, and a lower distance walked in the baseline 6-minute walk test. Kaplan-Meier survival analysis showed that at 3 years of follow-up the cumulative probability of HF or death was higher among blacks (29%) as compared with whites (22%; P = 0.05). Both black and white patients experienced similar and pronounced reductions in cardiac volumes with CRT-D therapy (all P values for comparison between the two groups >0.10). Risk reduction conferred by CRT-D therapy as not significantly different between blacks and whites (hazard ratio = 0.78 and 0.60, respectively; P for the difference = 0.44). However, possibly due to sample size limitations the CRT-D versus ICD only adjusted risk for HF/death in blacks was not statistically significant.


Black patients in MADIT-CRT experienced increased risk of HF or death as compared with whites, but displayed a similar magnitude echocardiographic response to CRT-D. These findings suggest that cardiac resynchronization therapy may be an effective therapeutic modality in black patients. However, further studies are needed to assess the clinical response to CRT-D in this high-risk population.