Undiagnosed Sleep-Disordered Breathing Worsens Heart Function in HCM Patients: JAMA
UK: Researchers have found in a new study that sleep-disordered breathing (SDB) is highly prevalent in hypertrophic cardiomyopathy (HCM) patients and is linked to adverse myocardial remodeling, greater diastolic dysfunction, and elevated troponin-T levels, indicating subclinical myocardial injury. The findings support further trials on treating SDB to improve outcomes in HCM.
The study, published in JAMA Cardiology by Shahid Karim, William Harvey Research Institute, NIHR Barts Biomedical Centre, Queen Mary University London, London, United Kingdom, and colleagues evaluated the burden of SDB in patients with HCM and its association with cardiac function and injury.
A total of 154 adults with HCM, identified from an institutional registry between 2018 and 2024, underwent overnight polysomnography, the gold standard for diagnosing sleep-disordered breathing. Participants with a prior diagnosis of SDB or pregnancy were excluded. Researchers assessed echocardiographic measures, biomarker levels, and functional status, with data analysis conducted independently of sleep study results.
The study led to the following findings:
- Sleep-disordered breathing (SDB) was identified in nearly 60% of patients, with most cases previously undiagnosed.
- Patients with SDB showed higher left ventricular mass, greater diastolic dysfunction, and elevated baseline troponin-T levels, along with larger overnight rises in troponin, pointing to subclinical myocardial injury.
- Over half of the HCM patients with SDB reported New York Heart Association class II or III symptoms, compared with only one-fourth of those without SDB.
- Hypertension and diabetes were more common in patients with SDB, while rates of atrial fibrillation and prior myectomy were comparable between groups.
The authors highlighted that SDB may play a key role in worsening the structural and functional abnormalities seen in HCM, adding to the overall disease burden. As SDB is often silent and under-recognized, its presence in this population may go unnoticed without systematic evaluation.
The researchers noted certain limitations, including the single-center design, predominantly European cohort, and reliance on routine echocardiograms, which may have introduced variability. Classifying all hypopneas as obstructive could also have underestimated the true burden of central sleep apnea.
The study highlights the importance of considering SDB as a comorbidity in patients with HCM, particularly in those with unexplained worsening of symptoms or evidence of diastolic dysfunction. The authors stressed the need for randomized clinical trials to determine whether treating SDB can improve remodeling, arrhythmic risk, and long-term outcomes in this patient population.
Reference:
Karim S, Chahal A, Venkataraman S, et al. Prevalence and Clinical Implications of Sleep Apnea in Hypertrophic Cardiomyopathy. JAMA Cardiol. Published online September 03, 2025. doi:10.1001/jamacardio.2025.2877
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