Prediction of ventricular arrhythmias and sudden cardiac death by quantification and location of late gadolinium enhancement on cardiac magnetic resonance: a systematic review and meta-analysis.

AIMS: In non-ischaemic cardiomyopathy (NICM), late gadolinium enhancement (LGE) detected by cardiovascular magnetic resonance is related to ventricular arrhythmia (VA) and sudden cardiac death (SCD) risk. The incremental prognostic value of quantifying LGE volume or mass beyond its mere presence, however, remains unresolved. The aim was to evaluate whether LGE quantification improves the prediction of SCD.

METHODS AND

RESULTS

PubMed, Embase, and Web of Science were searched on 20 November 2024 for observational studies that related quantified LGE burden to ventricular arrhythmia (VA)/SCD in NICM. Forty-one studies met prespecified criteria. Hazard ratios (HRs) were pooled with random-effects models, and quantification information was depicted in figures. Presence of any LGE was associated with a three-fold increase in VA/SCD risk (pooled HR 3.31, 95% confidence interval: 2.58-4.24). Beyond this binary marker, every additional 1% (or 1 g) of LGE was associated with a 12% relative risk increase (range 10-20%), independent of left ventricular ejection fraction and consistent across eight semi-automated thresholding techniques. This included 2-6 standard deviations above the reference myocardium and the full-width half-maximum method. Additionally, results were prone to substantial methodological heterogeneity (τ² = 1.49) and small-study bias. Once the presence of LGE was accounted for, scar quantification and location conferred minimal additional prognostic value.

CONCLUSION

Quantitative LGE assessment provides little incremental prognostic utility over dichotomous LGE detection. Consensus imaging standards and prospective validation are requisite before LGE burden can guide primary implantable cardioverter defibrillator allocation in NICM.