Evaluating biventricular diastolic function using cardiovascular magnetic resonance 4d-flow derived E/e'.

Aims
Cardiovascular magnetic resonance (CMR) imaging is a key modality for characterizing heart diseases, but is limited in assessing diastolic dysfunction (DD). 4D flow CMR now enables transvalvular blood flow quantification, while biventricular tissue relaxation can be quantified through annular tissue velocity and strain on standard cine images. This study investigated the utility of 4D-CMR-derived E/e' in evaluating biventricular diastolic function. Secondary aims included comparison with echocardiography to establish 4D-E/e' cutoffs for detecting unknown DD.Methods And Results
Diastolic transvalvular flow (4D-E) was quantified from 4D flow in 75 controls and 57 patients with cardiovascular disease. Tissue velocity (e') was assessed using cine-derived mitral/tricuspid annular velocity, longitudinal strain rate (e'FT-SR), and strain velocity (e'FT-vel). Biventricular 4D-E/e' was feasible across all e' methods, and significantly higher in patients than controls (P < 0.05). The patients were split into two subgroups: one with echocardiographic graded DD to derive CMR cutoffs, and a second with unassessed diastolic function. 4D-E/e' using annular velocity best distinguished patients with echocardiography-confirmed DD in the left (AUC = 0.90 ± 0.05, P < 0.01) and right heart (AUC = 0.81 ± 0.07, P < 0.01). Among patients without a diastolic assessment, 71% were identified with abnormal left ventricular diastolic function and 61% with abnormal right ventricular diastolic function when stratified against the lower 4D-E/e' cutoffs.Conclusion
4D-E/e', integrating transvalvular flow and tissue velocity, is feasible for biventricular diastolic function assessment. CMR identified previously unrecognized biventricular diastolic abnormalities in patients with cardiovascular disease, suggesting 4D-E/e' may be a valuable tool for early detection and referral for further diastolic testing.