New research suggests that implantable cardioverter defibrillators (ICDs) are not used as frequently for females and patients of colour, despite the increased use of ICDs in the management of patients with hypertrophic cardiomyopathy (HCM), over recent decades.
In patients with HCM, the heart muscle becomes abnormally thick, making it harder for the heart to pump blood. Consequently, patients may experience chest pain, shortness of breath or problems with the heart’s electrical system that can result in arrhythmias or sudden death in some cases.
Medication and surgical procedures can be used to address the symptoms of HCM, however, data from the National Inpatient Sample, an administrative database of inpatient hospitalisations, showed disparities regarding which patients receiving this during inpatient hospitalisations. In addition to this, regional variations in the use of ICDs for HCM were demonstrated.
“Racial disparities exist in HCM with regards to disease expression and worse outcomes. As with sex-specific differences, this could be the results of systemic bias with inequity of clinical care. The fact that ICD use is more common in large and teaching hospitals suggests that patients in smaller hospitals may not have access to specialists in HCM. Improving access to centers offering the highest level of specialised care may help reduce these disparities. How our findings relate to care access, socioeconomic status and patient-shared decision-making warrants further study,” says Sri Harsha Patlolla, study author and postdoctoral fellow in the Department of Cardiovascular Surgery at Mayo Clinic (Rochester, USA).
The Mayo Clinic study led by Patlolla et al, identified 23,535 adult hospitalisation for HCM, over a 12-year time period. The data showed that from 2003 — 2014, the proportion of patients who received an ICD increased from 11.6% to 17%. Overuse in some areas of the country were reflected through regional differences. Additionally, sex disparities were seen, with only 12.8% of women receiving ICDs, compared to 22.7% of males. Higher rates of ventricular arrhythmias were also seen across women, with women being more likely to receive an ICD only after experiencing heart electrical issues. Furthermore, a delay in women receiving ICDs was seen again, with other studies revealing women with HCMs are diagnosed later and are more symptomatic when compared to men.
Speaking on the disparities between sexes, Jeffrey Geske, a cardiologist at Mayo Clinic said: “It is possible that focusing on symptom management shifts focus away from sudden death risk assessment in women more than men, and shared decision-making may result in different choices between sexes. In combination with current findings, these suggest a need for providers to recognise sex-specific differences in outcomes and management trends in women with HCM.”
The study revealed that ICD use was similar across all races, but differences became apparent when considering patient demographics by race. Compared to white patients admitted to the hospital for HCM, patients of colour were younger, less affluent and more likely to receive care at a teaching hospital. Patients of colour also showed higher incidence of hypertension, kidney disease and atrial fibrillation.
Questions regarding these disparities were posed by Steve Ommen, a cardiologist and medical director of the Mayo Hypertrophic Cardiomyopathy Clinic. “Why are patient outcomes different based on sex and race? Does this reflect an inherent bias, or is it the result of underlying differences in disease expression? As further studies are pursued, providers should seek to eliminate potential bias in ICD decision-making, given the known mortality benefit associated with appropriate ICD implantation.”
