Predictive value of myocardial extracellular volume fraction for mortality and heart failure in known or suspected coronary artery disease patients

Background Extracellular volume (ECV) fraction measured by cardiac magnetic resonance (CMR) is an indicator of interstitial fibrosis and has demonstrated prognostic significance. This study aimed to assess the prognostic value of ECV in patients with known or suspected coronary artery disease. Methods This retrospective cohort study included patients who underwent CMR for clinical assessment of myocardial ischemia or viability between 2017 and 2019. Native and post-contrast T1 mapping was performed using the modified look-locker inversion protocol. Primary clinical outcomes were mortality and heart failure onset. The Cox proportional hazards model was employed to analyze predictors of clinical outcomes. Results A total of 2214 patients were included in the study. Their mean age was 68.7 ± 12.8 years, and 54.6% (1208 patients) were female. The mean ECV was 28.87 ± 5.17%, with a median value of 28.23% (interquartile range 25.91–31.05). Among the patients, 1107 (50%) had ECV values above the median, while 1107 (50%) had an ECV below the median. During a mean follow-up duration of 41.2 ± 13.2 months, 71 patients (3.2%) died, and 58 (2.6%) patients developed heart failure. ECV was found to be a predictor of composite outcomes, all-cause mortality, and heart failure, with adjusted hazard ratios and 95% confidence intervals of 1.99 (1.32–3.00, P ' 0.001), 1.91 (1.13–3.25, P = 0.016), and 1.94 (1.03–3.63, P = 0.041), respectively. Conclusions ECV is a valuable marker for predicting adverse clinical outcomes in patients with known or suspected coronary artery disease and may be useful for the risk stratification.