Elsevier

Heart Rhythm

Volume 6, Issue 3, March 2009, Pages 325-331
Heart Rhythm

Original-clinical
Device
Ethnic and racial disparities in cardiac resynchronization therapy

https://doi.org/10.1016/j.hrthm.2008.12.018Get rights and content

Background

Racial/ethnic differences in the use of cardiac resynchronization therapy with defibrillator (CRT-D) may result from underprovision or overprovision relative to published guidelines.

Objective

The purpose of this study was to examine the National Cardiovascular Data Registry (NCDR) ICD Registry for ethnic/racial differences in use of CRT-D.

Methods

We studied white, black, and Hispanic patients who received either an implantable cardioverter-defibrillator (ICD) or CRT-D between January 2005 and April 2007. Two multivariate logistic regression models were fit with the following outcome variables: (1) receipt of either ICD or CRT-D and (2) receipt of CRT-D outside of published guidelines.

Results

Of 108,341 registry participants, 22,205 met inclusion criteria for the first analysis and 27,165 met criteria for the second analysis. Multivariate analysis indicated CRT-eligible black (odds ratio [OR] 0.84; 95% confidence interval [CI], 0.75–0.95; P <.004) and Hispanic (OR 0.83; 95% CI, 0.71–0.99; P <.033) patients were less likely to receive CRT-D than were white patients. A substantial proportion of patients received CRT-D outside of published guidelines, although black (OR 1.18; 95% CI, 1.02–1.36; P = .001) and Hispanic (OR 1.17; 95% CI, 1.02–1.36; P = .03) patients were more likely to meet all three eligibility criteria.

Conclusion

Black and Hispanic patients who were eligible for CRT-D were less likely to receive therapy compared with white patients. Conversely, in the context of widespread out-of-guideline use of CRT-D, black and Hispanic patients were more likely to meet established criteria. Our findings suggest systematic racial/ethnic differences in the treatment of patients with advanced heart failure.

Introduction

Ethnic and racial disparities in provision of invasive cardiac procedures have been demonstrated in studies of clinical and administrative data in prospective and retrospective analyses.1 Reports by the Institute of Medicine and the National Academy of Sciences implicate a complex combination of patient-, provider-, and system-level factors in healthcare disparities.2, 3 An important cause of racial disparities in cardiovascular care is limited access to new technologies.4

Congestive heart failure (CHF) with systolic dysfunction is a morbid condition that affects 5.2 million Americans, with symptomatic heart failure carrying a worse prognosis at one year than the majority of cancers.5 Cardiac resynchronization therapy (CRT) is a relatively new treatment of severe systolic heart failure. An estimated 1% to 3% of patients discharged alive after an index hospitalization for CHF and 15% to 20% of patients in specialized heart failure clinics are potential candidates.6 Multiple large randomized clinical trials have demonstrated reduction in hospitalizations and mortality as well as improvements in exercise tolerance and quality of life among patients treated with CRT.7, 8, 31 The indications for CRT and implantable cardioverter-defibrillator (ICD) therapy frequently overlap, and patients increasingly receive CRT combined with a defibrillator (CRT-D).

In 2005, the Centers for Medicare & Medicaid Services (CMS) expanded coverage of ICDs and CRT-Ds, mandating that all Medicare patients receiving either device be enrolled in the National Cardiovascular Data Registry (NCDR) ICD Registry.9 We examined the initial data from this registry to test the hypothesis that racial/ethnic minority patients were less likely to receive CRT-D implantation than ICD therapy alone, as CRT-D is a newer technology requiring access to physicians and hospitals with substantial clinical expertise. Racial/ethnic differences in cardiac care also may result from out-of-guideline provision of care among whites.10 Therefore, we also hypothesized that white patients were more likely than black and Hispanic patients to receive CRT-D outside of established clinical guidelines.

Section snippets

Methods

The NCDR ICD Registry is a CMS-mandated national database developed in collaboration with the American College of Cardiology (ACC) and the Heart Rhythm Society (HRS).11 Enrollment began in January 2005 and is mandatory for Medicare beneficiaries with an indication of primary prevention of sudden cardiac death. Enrollment is voluntary for non-Medicare patients, although there has been widespread registration of all device recipients, and approximately 72% of all implantations are represented.12

Demographic and clinical characteristics

Between January 2005 and April 2007, 107,723 patients were entered in the NCDR ICD Registry. Two cohorts were examined: patients who met CRT-D guidelines and those who underwent CRT-D implantation. In both cohorts, fewer than 4% of patients were excluded because they were not classified as white, black, or Hispanic (3.7% and 3.9%, respectively). All variables in the analysis had less than 1% missing values, with the exception of CHF duration (4.8%).

Demographic characteristics of the two cohorts

Discussion

We examined the recently established NCDR ICD Registry for racial and ethnic disparities in CRT-D implantation. We hypothesized that disparities for this procedure would be prevalent because the technology is relatively new and requires clinicians with more experience and training than necessary for ICD placement alone. Our findings provide evidence that even when minority patients surmount well-described barriers to the receipt of cardiovascular procedures, they are less likely to receive the

Conclusion

CRT-D-eligible Hispanic and black patients in the NCDR ICD Registry were less likely to receive CRT-D therapy than were eligible white patients. Conversely, white patients were more likely to receive CRT-D outside of published guidelines. Both effects reflect unexplained racial/ethnic differences in treatment for patients with advanced heart failure. These findings suggest an important opportunity to improve care by expanding access to CRT-D therapy for eligible minority patients.

Acknowledgements

We are grateful for manuscript editing assistance provided by Alexis Greenhut, MPH, and Christine Camacho, BA, and graphical expertise provided by Janell Olah, MFA.

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    This research was supported by the American College of Cardiology/National Cardiovascular Data Registry. Dr. Groeneveld was supported by a Research Career Development Award from the Department of Veterans Affairs.

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