Findings from a study supported in part by the National Institutes of Health (NIH) have identified a new model for predicting outcomes for hypertrophic cardiomyopathy (HCM), a heart condition with a prevalence of 1 in 500 people and a frequent cause of sudden cardiac death. Specifically, the findings demonstrate that incorporating prospective data including clinical history, imaging, and blood biomarker data into risk assessment can improve prediction of adverse cardiac events in people with HCM.
The large, international study, called the Hypertrophic Cardiomyopathy Registry, was initially funded by NIH's National Heart, Lung, and Blood Institute (NHLBI). The findings were published in JAMA.
"Current risk prediction guidelines for hypertrophic cardiomyopathy are imperfect, as they predict only sudden cardiac death, and not heart failure or other fatal and nonfatal cardiac adverse events," said Christopher Kramer, M.D., a principal investigator of the study and cardiologist at the Heart and Vascular Center of the University of Virginia Health System. "This study is a major advance in that it provides evidence that incorporating these additional assessment methods better predicts risk of adverse outcomes."
Hypertrophic cardiomyopathy occurs when the heart muscle becomes larger and thicker than normal, which can block the outflow of the left ventricle, leading to heart failure symptoms, and can lead to rapid, life-threatening heart rhythm abnormalities. It is commonly inherited, and many people with the condition are asymptomatic, pointing toward the need for better risk prediction. The researchers in this study wanted to see if integrating new methods into assessment-including a health history questionnaire, blood sampling for biomarkers and genotyping, and contrast-enhanced cardiac magnetic resonance imaging (MRI)-could more accurately predict adverse events such as sudden cardiac death, heart failure, nonfatal arrythmias, and the need for device implantation or heart transplantation.
The study enrolled close to 2,700 patients with HCM in North America and Europe at 44 sites that had expertise in HCM and cardiac imaging. The researchers collected medical history, blood tests, and cardiac imaging, and followed the study participants for seven years on average. Through this work, they determined that several predictors such as scarring, weight, and function of the heart muscle seen by imaging; history of heart failure; and higher levels of a blood biomarker (NTproBNP), were associated with fatal and nonfatal cardiac events. Sudden cardiac death outcomes were predicted by determining structure and function of the left ventricle by cardiac MRI and the blood biomarker tests. In short, they showed that integrating these study methods into risk assessment gave fuller and more accurate predictions of adverse events.
"This study provides strong evidence for incorporating cardiac MRI and blood biomarkers into risk prediction for people with HCM," said David Goff, M.D., Ph.D., acting director of NHLBI. "This condition has significant morbidity and mortality, and advances in risk prediction like this have the potential to change disease management and improve outcomes for patients."
