Transmitral flow analysis via valve tracking 4D flow MRI detects age- and sex-related diastolic changes

To evaluate whether valve tracking 4D flow MRI can detect subtle age- and sex-related changes in left ventricular (LV) diastolic function in healthy adults. We retrospectively recruited healthy adults who had undergone cardiac MRI between October 2020 and March 2022, selecting those with whole-heart 4D flow MRI, 2D long-axis cine, and short-axis cine acquisitions. A dynamic plane at the mitral valve (MV) level was generated in 4D flow MRI using leaflet insertion points tracked on 2- and 4-chamber cine images. Through-plane velocities were computed from 4D flow data and corrected for MV motion. After contouring the transmitral region, early and late diastolic peak flow rates (E flow , A flow ), peak velocities (E vel, A vel ), and mitral forward flow volume (MFVol) were measured. Peak early LV relaxation velocity (E MV ) was defined as the peak through-plane velocity of MV plane motion. A total of 39 adults (age range: 46 ± 13; 20 women) were included. With age, both E flow /A flow ( r = − 0.79, p < 0.0001, adjusted for HR) and E vel /A vel ( r = − 0.70, p < 0.0001, adjusted for HR) were significantly decreased, while E vel /E MV increased ( r = 0.53, p < 0.001, adjusted for EDV). Early diastolic changes were sex-specific; women showed decreased E flow and increased E vel /E MV with aging, whereas men showed no significant associations. Additionally, the normalized E flow /MFVol decreased with aging, significantly in the sex-combined cohort ( r = − 0.42, p = 0.008) and in women ( r = − 0.68, p = 0.004), but not in men. Transmitral flow rates and peak velocities assessed by 4D flow MRI with cine-based valve tracking effectively detected physiologic age-related declines in diastolic function, exhibiting sex-specific differences.