To assess the effectiveness of various risk stratification methods for sudden cardiac death (SCD) in patients with non-ischemic dilated cardiomyopathy (NICM) and low left ventricular ejection fraction (LVEF) ≤35%.
Key Findings:
Low LVEF alone is insufficient for distinguishing between arrhythmic and nonarrhythmic mortality.
No noninvasive or invasive markers consistently improved predictive accuracy for SCD beyond LVEF.
CMR imaging with LGE shows promise in identifying myocardial fibrosis associated with SCD but lacks guideline-level validation.
Genetic factors may influence arrhythmic risk in NICM, with certain variants linked to higher arrhythmic events, highlighting the need for genetic consideration in risk assessment.
Interpretation:
Current risk stratification methods for SCD in NICM are inadequate, necessitating a more integrated approach that includes CMR imaging and genetic factors for improved accuracy.
Limitations:
Methodological heterogeneity in studies and lack of randomized trials for CMR parameters may impact the reliability of findings.
No single marker has achieved guideline-level validation as a replacement for LVEF.
Challenges in standardizing CMR acquisition and quantification hinder its widespread application.
Conclusion:
Future research should focus on developing standardized multimodal risk models and dynamic biomarkers to enhance SCD risk stratification in NICM.
