Prognosis and Risk Stratification in Dilated Cardiomyopathy With LVEF≤35%: Cardiac MRI Insights for Better Outcomes

Area of Science:

• Cardiology
• Medical Imaging
• Preventive Medicine

Background:

• Current guidelines recommend implantable cardioverter-defibrillators (ICDs) for primary prevention of sudden cardiac death (SCD) in dilated cardiomyopathy (DCM) patients with left ventricular ejection fraction (LVEF) ≤35%.
• The effectiveness of ICDs is limited by the inability to reliably differentiate SCD risk from heart failure deterioration, impacting clinical utility.
• This study aimed to improve SCD risk stratification in DCM patients with LVEF ≤35% using cardiac magnetic resonance imaging (CMR).

Purpose of the Study:

• To refine the risk stratification model for SCD in patients with dilated cardiomyopathy and LVEF ≤35%.
• To identify imaging biomarkers from CMR that predict SCD risk more accurately.
• To potentially enhance decision-making for ICD implantation in high-risk patients.

Main Methods:

• A total of 1272 patients with DCM and LVEF ≤35% who underwent CMR were enrolled.
• The study assessed the primary endpoint of SCD or aborted SCD and the secondary endpoint of heart failure death or heart transplantation.
• Statistical analysis included adjusted Cox regression to identify predictors of SCD and competing risks analysis.

Main Results:

• Late gadolinium enhancement (LGE) ≥7.5% on CMR was a strong independent predictor of SCD or aborted SCD (HR, 4.11).
• Other predictors included age, family history of SCD, NT-proBNP, and LVEF.
• Patients with LGE ≥7.5% and LVEF ≤20% had a 7.12-fold higher risk of SCD events compared to those with LGE <7.5%.

Conclusions:

• Patients with DCM and LGE ≥7.5% are at heightened risk for SCD events.
• CMR-derived LGE can be utilized for improved SCD risk assessment in this population.
• Integrated risk stratification combining clinical factors and CMR findings may guide ICD therapy decisions.