Quantitative Late Gadolinium Enhancement Cardiac Magnetic Resonance and Sudden Death in Hypertrophic Cardiomyopathy

Quantitative late gadolinium enhancement (LGE) cardiac magnetic resonance provides important prognostic information for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM). However, it has not been fully integrated into clinical practice. To assess the prognostic value of LGE extent in predicting SCD in adults with HCM across different methods of quantification, thresholds, and patients' clinical profile. The authors searched PubMed, Web of Science, and Cochrane Library for studies investigating the prognostic value of LGE% in predicting SCD in HCM. Pooled odds ratios were calculated with 95% CIs. The optimal threshold was determined using a multiple cutoffs model. Eleven studies were included in the meta-analysis with a total of 5,550 patients and a median follow-up time of 5.2 years. Two studies quantified LGE manually, 7 studies used the 6 SD technique, 1 study used the 4 SD technique, and 1 study the 2 SD technique. There was no statistically significant difference in predicting SCD between these 4 methods (P = 0.443). Optimal cutoff could be determined only for the 6 SD technique. LGE 10% was the optimal threshold of the 6 SD technique with sensitivity 0.73 and specificity 0.67. The different LGE quantification techniques have comparable accuracy in predicting SCD. When the more extensively studied 6 SD technique is used, LGE 10% is the optimal cutoff and can effectively restratify intermediate-risk patients. LGE extent can improve HCM risk stratification, but it is unlikely to become a standalone tool.