Enhanced MRI Technique Improves Risk Prediction in Children with Hypertrophic Cardiomyopathy

A new study highlights the potential of late gadolinium enhancement (LGE) in cardiovascular magnetic resonance imaging (MRI) to improve the prediction of sudden cardiac death risk in children with hypertrophic cardiomyopathy (HCM). HCM is the most common genetic cardiovascular condition and a leading cause of sudden cardiac death in young people, with an annual mortality rate of approximately 1%. Despite this, most patients with HCM—including those at higher risk—often present with few or no symptoms, making accurate risk prediction challenging. While current risk models primarily rely on patient test scores and echocardiograms, adding LGE may significantly enhance clinicians' ability to identify high-risk patients.

A Game-Changer in Pediatric Risk Assessment

For the first time, researchers have evaluated the utility of LGE in children with HCM, building on earlier studies that established its efficacy in adults. Led by Jon Detterich, MD, Principal Investigator in the Heart Institute at Children's Hospital Los Angeles, a multi-institutional team conducted a 7-year retrospective cohort study. This study included 700 pediatric patients with HCM from 37 international sites.

The findings revealed that patients with greater levels of LGE—defined as 10% or more of total myocardial mass—were at over twice the risk of sudden cardiac death compared to those with lower levels. Additionally, these patients exhibited lower left ventricular ejection fractions and larger left atrial diameters, factors that are also associated with worse cardiac outcomes. These results underscore the potential for LGE to complement current risk stratification models by providing more detailed insights into heart health.

Enhancing Current Risk Stratification Models

By integrating LGE into established tools such as HCM Risk-Kids and the PRIMaCY score, researchers demonstrated an improvement in predictive accuracy for identifying children at higher risk of sudden cardiac death. "The higher the LGE, the more predictive the score was at estimating patient risk and outcomes," stated Dr. Detterich. This quantifiable metric offers clinicians a clearer understanding of a patient’s prognosis and the potential need for early interventions.

Why This Matters: Targeting High-Risk Patients

LGE imaging allows clinicians to visualize myocardial scarring—an indicator of damaged tissue and impaired cardiac function. Larger areas of scarring, reflected in higher LGE levels, are predictive of worse outcomes, including sudden cardiac death. According to Dr. Detterich, "The larger amount of late gadolinium enhancement indicates larger areas of scarring, which is predictive of worse cardiac function and sudden cardiac death. This method can help us to distinguish the high-risk patients who would benefit from more immediate and intensive monitoring, therapies, and interventions—like an implantable defibrillator or surgery—from the patients at low risk of cardiac issues."

These findings could have life-saving implications for pediatric HCM patients by enabling earlier interventions, such as implantable defibrillators or surgical procedures, for those deemed high-risk.

Future Directions for Pediatric Care

As HCM remains a complex and challenging condition to predict and manage, this study highlights the promise of integrating advanced imaging techniques like LGE into routine clinical practice. By enhancing existing risk stratification models, this approach has the potential to reduce mortality and improve long-term outcomes for pediatric HCM patients. Further research and broader clinical adoption of LGE could shift the standard of care for these high-risk patients, offering them improved prognoses and quality of life.