Relationship between ECV and diastolic dysfunction over time. Longitudinal comparison of ECV between patients with normal diastolic function (blue boxes) and those with diastolic dysfunction (red boxes) across 3 time points. A mixed-effects model demonstrated a significant overall difference in ECV based on the presence of diastolic dysfunction (P = .001), with no significant effect of time (P = .38) or time × diastolic dysfunction interaction (P = .85), indicating that group differences in ECV were consistent over time.