Extracellular volume and left ventricular hypertrophy by cardiac magnetic resonance are independent predictors of cardiovascular outcome in obesity

Abstract

This retrospective cohort study investigated for association between increased extracellular volume (ECV) and left ventricular hypertrophy (LVH) by cardiac magnetic resonance (CMR) and cardiovascular composite outcomes in obesity. Native T1 was measured at the ventricular septum. ECV was calculated from native and post-contrast T1 and hematocrit. Cardiovascular (CV) composite outcomes included acute myocardial infarction, unstable angina requiring hospitalization, myocardial revascularization (excluding early revascularization), heart failure, and CV death. A total of 456 patients with a mean follow-up of 2.1 ± 0.4 years were enrolled. LGE and LVH was detected in 30.5% and 9.2%. 107 patients (23.5%) had the composite outcomes. Multivariable analysis revealed that LGE, LVH, and high ECV as independent predictors for cardiovascular composite outcomes The event rate in the LVH and high ECV, the LVH alone, the high ECV alone, and the no-LVH with lower ECV group was 57.1%, 38.1%, 32.6%, and 17.7%, respectively. Assessment of incremental prognostic value by comparing global chi-square showed that high ECV had additional prognostic value on top of LGE, and LVH. LVH and high ECV are independent predictors of CV composite outcomes in obesity. This is the first study that demonstrate the prognostic value of ECV in obese population.