Aortic Pulse Wave Velocity Evaluated by 4D Flow MRI Across the Adult Lifespan

BACKGROUND

Evaluation of aortic stiffness by pulse wave velocity (PWV) across the adult lifespan is needed to better understand normal aging in women and men.

PURPOSE

To characterize PWV in the thoracic aorta using 4D flow MRI in an age- and sex-stratified cohort of healthy adults.

STUDY TYPE

Retrospective.

POPULATION

Ninety nine healthy participants (age: 46 ± 15 [19-79] years, 50% female), divided into young adults (<45 years) (N = 48), midlife (45-65 years) (N = 37), and later life (>65 years) (N = 14) groups.

FIELD STRENGTH/SEQUENCE

1.5 T or 3 T, 2D cine bSSFP, 4D flow MRI.

ASSESSMENT

Cardiac functional parameters of end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and myocardial mass were assessed by 2D cine bSSFP. PWV and aortic blood flow velocity were assessed by 4D flow MRI. Reproducibility of PWV was evaluated in a subset of nine participants.

STATISTICAL TESTS

Analysis of variance, Pearson's correlation coefficient (r), linear regression, intraclass correlation coefficient (ICC). A P value < 0.05 was considered statistically significant.

RESULTS

PWV increased significantly with age (young adults: 5.4 ± 0.9 m/sec, midlife: 7.2 ± 1.1 m/sec, and later life: 9.4 ± 1.8 m/sec) (r = 0.79, slope = 0.09 m/sec/year). PWV did not differ in women and men in entire sample (P = 0.40) or within age groups (young adults: P = 0.83, midlife: P = 0.17, and later life: P = 0.96). PWV was significantly correlated with EDV (r = -0.29), ESV (r = -0.23), SV (r = -0.28), myocardial mass (r = 0.21), and mean aortic blood flow velocity (r = -0.62). In the test-retest subgroup (N = 9), PWV was 6.7 ± 1.5 [4.4-9.3] m/sec and ICC = 0.75.

DATA CONCLUSION

4D flow MRI quantified higher aortic PWV with age, by approximately 1 m/sec per decade, and significant differences between young adults, midlife and later life. Reproducibility analysis showed good test-retest agreement. Increased PWV was associated with decline in cardiac function and reduced aortic blood flow velocity. This study demonstrates the utility of 4D flow MRI-derived aortic PWV for studying aging.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

The assessment of cardiac function with tissue Doppler imaging in fetuses with congenital diaphragmatic hernia

Introduction: This study aimed to evaluate the cardiac function of fetuses with congenital diaphragmatic hernia by conventional echocardiography and spectral tissue Doppler imaging (s-TDI) and to evaluate the relationship between cardiac function and the severity of pulmonary hypoplasia. We also aimed to investigate the effect of diaphragmatic hernia side on fetal cardiac function.Methods: Fetal cardiac function were evaluated in 28 fetuses (20 with left-sided and 8 with right-sided) complicated with isolated congenital diaphragmatic hernia (CDH) and 56 gestational age matched control in this single center prospective study. s-TDI measurements were obtained at the right atrioventricular valve annulus. The annular peak velocities and their ratios, the time periods of cardiac cycle and myocardial performance index were calculated.Results: In comparison to controls, significantly prolonged isovolumetric contraction time (ICT') and isovolumetric relaxation time (IRT') and, significantly shortened ejection time (ET') were observed in fetuses with CDH by s-TDI. Fetuses with CDH also had higher myocardial performance index (MPI') z-scores compared to controls. There were no significant differences in terms of s-TDI cardiac function parameters between fetuses with right- and left-sided CDH. In correlation analysis, a significant positive correlation was found between ET' value and o/e LHR.Conclusion: The signs of both systolic and diastolic altered function were observed in fetuses with CDH with s-TDI independent of the side of the hernia, and a significant positive correlation was observed between fetal cardiac systolic function and the severity of pulmonary hypoplasia.