1345199 - Myocardial tissue characteristics based sudden cardiac death risk stratification in non-ischemic dilated cardiomyopathy

Sudden cardiac death (SCD) was one of leading causes of death in patients with non-ischemic dilated cardiomyopathy (DCM). However, the risk stratification of SCD events remains challenging in clinical practice. The study was to determine whether the myocardial tissue characteristics could predict SCD events and explore a new SCD stratification algorithm in patients with non-ischemic DCM.

Methods: In this study, we prospectively enrolled 858 patients with non-ischemic DCM who underwent cardiac magnetic resonance (CMR), including T1 mapping and late gadolinium enhancement (LGE). Competing risk regression analysis was performed to identify the association of tissue characteristics with SCD related events.

Results:

During a median of 33.0 (interquartile range: 20.4 - 51.6) months follow-up, 70 (8.2%) patients experienced SCD related events and 97 (11.3%) patients experienced heart failure (HF) related events. In multivariate competing risk analysis, extracellular volume fraction (ECV) was independent predictor of SCD related events (per 3% increase, hazard ratio [HR] 1.26, 95% confidence interval [CI] 1.11 - 1.44, P < 0.001) and HF related events (per 3% increase, HR 1.16, 95% CI 1.04 - 1.29, P = 0.008). Native T1 was only independently associated with SCD related events (per 10ms increase, HR 1.07, 95% CI 1.04 - 1.11, P < 0.001), not HF related events. Left ventricular ejection fraction (LVEF) was not significant predictor of SCD related events in the multivariable analysis. Native T1 >= mean reference value + 4SD combined with positive LGE identified the highest SCD risk group with annual event rate of 10.2%, while the annual event rate for patients with native T1 < mean reference value + 2SD combined with negative LGE was only 0.6%. A new SCD risk stratification category was developed with a combination with native T1 and LGE. This category showed good prediction ability (C-statistics = 0.74) and could discriminate SCD risk and the competing heart failure events risk.

Conclusion: A new myocardial tissue characteristic based risk stratification may be a useful tool to guide clinical decision making for SCD prevention in non-ischemic dilated cardiomyopathy.