CARDIAC magnetic resonance (CMR) imaging has identified key predictors of sudden cardiac events (SCE) in patients with Fontan circulation, with factors such as ventricular dilatation and mild dysfunction, NYHA functional class, and a history of protein-losing enteropathy/plastic bronchitis showing strong associations.
Among patients with congenital heart disease, those with single ventricles, such as those with Fontan circulation, face an elevated risk of early mortality, with sudden cardiac death being a significant contributor. Predicting and preventing such events could enhance patient outcomes. The Fontan Outcomes Registry Using CMR Examinations (FORCE) aimed to identify the prevalence of sudden cardiac events and the risk factors associated with them in this specific patient group, providing valuable insights into prevention strategies.
This international registry study included 3,132 patients with Fontan circulation, with 41% of participants being female. The median age at the time of the first cardiac MRI was 14.6 years. Over a median follow-up period of 4 years, 3.5% (109 patients) experienced an SCE. Of these, 36% (39 patients) died. The study identified several significant risk factors for SCE through multivariable analysis, including NYHA functional class >II (HR: 4.91, P<0.0001), a history of protein-losing enteropathy/plastic bronchitis (HR: 2.37, P=0.0082), a single-ventricle end-diastolic volume index >104 mL/m² (HR: 3.15, P<0.0001), and ejection fraction <50% (HR: 1.73, P=0.0437). Kaplan-Meier analysis revealed that patients without these risk factors had a 4-year freedom from SCE of 99.5%.
SCE occurred in 3.5% of patients with Fontan circulation in this cohort, with one-third of those affected dying as a result. Risk factors identified, including mild ventricular dysfunction, dilatation, NYHA functional class, and a history of protein-losing enteropathy/plastic bronchitis, can inform clinical practice by identifying high-risk patients. Future research should focus on integrating these findings into clinical decision-making, potentially guiding monitoring protocols and interventions for Fontan patients to reduce the incidence of SCE. The role of CMR in predicting arrhythmic events should be further explored to refine risk stratification and improve patient care.
Katrina Thornber, EMJ
Reference
Wolfe NK et al. Cardiac MRI predictors of arrhythmic sudden cardiac events in patients with fontan circulation. JACC. 2024;84(25):2417-26.
