Prognostic Value of Myocardial T1 Mapping for Predicting Adverse Events in Hypertrophic Cardiomyopathy

BACKGROUND: In patients with hypertrophic cardiomyopathy, the prognostic value of myocardial T1 and extracellular volume fraction for adverse cardiovascular events has not been well defined. METHODS: A total of 663 consecutive participants with hypertrophic cardiomyopathy who underwent 3T cardiovascular magnetic resonance were recruited. The follow-up end points included heart failure (HF)-related death, HF hospitalization, and sudden cardiac death or aborted sudden cardiac death. RESULTS: On Cox proportional hazards regression multivariable analyses, global native T1 excluding late gadolinium enhancement areas (hazard ratio [HR], 1.04 [95% CI, 0.99–1.09]; P =0.094) and global extracellular volume fraction excluding late gadolinium enhancement (HR, 1.02 [95% CI, 0.95–1.10]; P =0.565) were not associated with sudden cardiac death. Conversely, global native T1 (HR, 1.08 per 10 ms increase [95% CI, 1.02–1.16], P =0.014; HR, 1.05 per 10 ms increase [95% CI, 1.01–1.09]; P =0.009) and global extracellular volume fraction (HR, 1.23 per 1% increase [95% CI, 1.11–1.36], P <0.001; HR, 1.10 per 1% increase [95% CI, 1.04–1.16]; P <0.001) were independently associated with HF-related death and the composite end point of HF-related death or HF hospitalization in multivariable Cox models, respectively. CONCLUSIONS: In this study of patients with hypertrophic cardiomyopathy, we found global native T1 and global extracellular volume fraction (excluding late gadolinium enhancement) to be both independently associated with HF-related events, but not sudden cardiac death in multivariable analysis. These findings are hypothesis-generating and will require external validation in larger cohorts. REGISTRATION: URL: https://www.chictr.org.cn ; Unique identifier: ChiCTR1900024094.