NEW YORK (Reuters Health) - Black patients with hypertrophic cardiomyopathy (HCM) tend to be diagnosed younger, are less likely to carry a sarcomere mutation, have more functional limitations and experience less optimal care than their white counterparts, a registry study suggests.
"As providers, we often think about the patients we see every day in our clinic," Dr. Lauren Eberly of Brigham and Women's Hospital in Boston told Reuters Health by email. "But we need to start thinking about who is out there in the community that we aren't seeing because they couldn't make it through the door."
"Although this is one the largest multicenter cohorts to evaluate the association of race and clinical outcomes, we still had a very low proportion of black patients," she said. "This points to major barriers in referral for subspecialty HCM care."
"Unfortunately, our results show that even when black patients are able to make it to a subspecialist, there are inequities in the quality of care they receive," she noted. "They are less likely to receive important therapies and genetic testing. Barriers to accessing care and inequitable care delivery is liking a major driver of the disparate heart failure outcomes that we found among black patients with HCM."
"Nearly all previous studies of HCM have reflected the experience of white patients," she added.
"It's time for this to change."
The study, published in JAMA Cardiology, included data from 1989-2018 on black and white HCM patients in the U.S.-based sites of the Sarcomeric Human Cardiomyopathy Registry.
Overall, 2,467 patients were identified. The mean age was about 42, about 60% were men, and only 8.3% were black.
Compared with whites, black patients were younger at the time of diagnosis (mean, 36.5 vs. 41.9); had higher prevalence of New York Heart Association class III or IV heart failure at presentation (22.6% vs. 15.8%); had lower rates of genetic testing (54.1% vs. 62.1%); and were less likely to have sarcomeric mutations (26.1% vs. 40.5%).
Black race was also associated with increased development of NYHA class III or IV heart failure (hazard ratio, 1.45); the association persisted on multivariable Cox proportional hazards regression (HR, 1.97).
Cardioverter-defibrillator implantations were similar between the groups, but invasive septal reduction was less common among blacks (14.6% vs. 23.0%).
Blacks had a lower rate of incident atrial fibrillation (17.1% vs. 26.9%). However, race was not associated with differences in stroke, ventricular arrhythmias, all-cause mortality, or the overall composite outcome.
"Further study is needed to assess whether higher rates of heart failure may be associated with underlying ancestry-based disease pathways, clinical management, or structural inequities," the authors conclude.
Coauthor Dr. Neal Lakdawala, also of Brigham and Women's Hospital, told Reuters Health by email, "At present, we would urge our colleagues in primary care and general cardiology to consider HCM as a cause of left ventricular hypertrophy in black patients. This should prompt referral to a clinic or center experienced in the management of HCM, where genetic testing and expert clinical care can be provided."
Cardiac electrophysiologist Dr. David Briceno, Director, Hypertrophic Cardiomyopathy Center, Montefiore Einstein Center for Heart and Vascular Care in New York City, commented by email, "Despite some limitations, including referral bias and the limited number of black patients analyzed, the findings...add insight into the disease experience of HCM in black patients, and seem consistent with previous reports."
"The challenges in the care of HCM patients, particularly minorities, are significant," he told Reuters Health. "Previous studies have established lower referral of black patients for advanced cardiac care, including cardiac catheterization, cardiac resynchronization therapy, and cardiology specialty visits."
"The findings of the current study," he said, "suggest that black patients with HCM may be underrecognized and under-referred for effective therapies, such as risk stratification and invasive septal reduction therapies, which may be related to the lower rates of implantation of cardioverter-defibrillators in black patients with HCM seen in other studies."
"In my view," he added, "it is critical to improve the awareness and recognition of HCM not only in black patients, but in other underserved minorities, to permit access to appropriate and effective risk stratification and therapies."
SOURCE: http://bit.ly/2PDmuXC JAMA Cardiology, online December 4, 2019.