Expression and Outcomes of Hypertrophic Cardiomyopathy in Black and White Patients – The Cardiology Advisor

Hypertrophic cardiomyopathy in black vs white patients may be associated with a greater burden of functional heart failure and reduced access to care and genetic testing, according to a study published in JAMA Cardiology.

The rate of cardiovascular mortality and heart failure is highest in black patients; however, there is little data on the clinical characteristics and outcomes in black patients with hypertrophic cardiomyopathy (HCM).

In this retrospective cohort study, researchers assessed data on black and white patients with HCM who were evaluated between 1989 and 2018 at 7 US sites that participated in the Sarcomeric Human Cardiomyopathy Registry. The overall composite outcome was defined as the first occurrence of any component of the ventricular arrhythmic composite end point, cardiac transplant or implantation of a left ventricular assist device, New York Heart Association (NYHA) class III or IV heart failure, atrial fibrillation, stroke, or all-cause mortality. Multivariable analysis was used to further investigate outcomes including septal reduction therapies, atrial fibrillation, and baseline characteristics of heart failure between racial groups. Cox regression modeling was used to examine the association between race and the development of heart failure.

Of the 2467 patients included in the analysis, 8.3% were black (n=205) and 91.7% were white (n=2262). At diagnosis, the mean age of black patients was 5 years younger than the mean age of white patients (mean, 36.518.2 vs 41.920.2 years, respectively; P <.001). Black patients had higher rates of NYHA class III or IV heart failure at diagnosis compared with white patients (36 of 205 [22.6%] vs 174 of 2262 [15.8%], respectively; P <.001). The use of genetic testing was significantly lower among black patients compared with white patients (54.1% vs 62.1%, respectively; P =.03), and black patients were found to be less likely to have a pathogenic sarcomeric mutation compared with white patients (26.1% vs 40.5%, respectively; P =.006).

Black patients underwent fewer invasive septal reduction therapies than white patients (14.6% vs 23.0%, respectively; P =.007), but rates of implantation of cardioverter defibrillators was comparable for black and white patients (33.2% vs 32.0%, respectively; P =.79). Rates of atrial fibrillation were lower in black patients vs white patients (17.1% vs 26.9%, respectively; P <.001). Additionally, 24.8% of black patients and 19.5% of white patients developed NYHA class III or IV heart failure during follow up (P =.05). After adjusting for sarcomere status, age at diagnosis, hypertension, body mass index, and presence of obstruction, black race was found to be independently associated with the development of NYHA class III or IV heart failure (hazard ratio, 1.97; 95% CI, 1.34-2.88; P <.001).

Limitations to this study included survival bias, and referral bias. Additionally, levels of perceived discrimination and differences in socioeconomic status may have contributed to worse prognosis.

Despite significant advances in the understanding of the molecular pathogenesis in HCM and successes of modern treatment, racial disparities exist, reflective of the state of general cardiovascular health in the United States, noted the study authors. Increased minority group representation in genomic and cohort studies and for addressing barriers for appropriate diagnosis and receipt of specialized care appears to be needed. Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors disclosures.

Reference

Eberly LA, Day SM, Ashley EA, et al. Association of race with disease expression and clinical outcomes among patients with hypertrophic cardiomyopathy [published online December 4, 2019]. JAMA Cardiol. doi: 10.1001/jamacardio.2019.4638

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Expression and Outcomes of Hypertrophic Cardiomyopathy in Black and White Patients - The Cardiology Advisor