CMR based measurement of aortic stiffness, epicardial fat, left ventricular myocardial strain and fibrosis in hypertensive patients

Abstract

Introduction: A combined assessment of different parameters of cardiovascular (CV) risk and prognosis can be supportive and performed with cardiac magnetic resonance (CMR). Aortic stiffness, epicardial fat volume (EFV), left ventricular (LV) strain and fibrosis were evaluated within a single CMR examination and results were related to the presence of hypertension (HTN) and diabetes mellitus (DM). Methods: 20 healthy controls (57.2 ± 8.2 years(y); 26.2 ± 3.9 kg/m2), 31 hypertensive patients without DM (59.6 ± 6.7 y; 28.4 ± 4.7 kg/m2) and 12 hypertensive patients with DM (58.8 ± 9.9y; 30.7 ± 6.3 kg/m2) were examined at 1.5Tesla. Aortic stiffness was evaluated by calculation of aortic pulse wave velocity (PWV), EFV by a 3D-Dixon sequence. Longitudinal & circumferential systolic myocardial strain (LS; CS) were analyzed and T1-relaxation times (T1) were determined to detect myocardial fibrosis. Results: EFV was highest in hypertensive patients with diabetes (78.4 ± 28.0 ml/m2) followed by only hypertensive patients (64.2 ± 27.3 ml/m2) and lowest in controls (50.3 ± 22.7 ml/m2; p < 0.05). PWV was higher in hypertensive patients with diabetes (9.8 ± 3.3 m/s) compared to only hypertensive patients (8.6 ± 1.7 m/s; p < 0.05) and to controls (8.1 ± 1.9 m/s; p < 0.05). LS&CS were worse in hypertensive patients with diabetes (LS:-20.9 ± 5.1% and CS: −24.4 ± 5.7%) compared to both only hypertensive patients (LS: −24.7 ± 4.6%; CS: −27.1 ± 5.0%; p < 0.05) and to controls (LS: −25.5 ± 3.8; CS: −28.3 ± 4.1%; p < 0.05). Both hypertensive groups with and without DM had higher T1́s (994.0 ± 43.2 ms; 991.6 ± 35.5 ms) than controls (964.6 ± 40.3 ms; p < 0.05). Conclusion: CMR revealed increased aortic stiffness and EFV in hypertensive patients, which were even higher in the presence of DM. Also signs of LV myocardial fibrosis and a reduced strain were revealed. These parameters support the assessment of CV risk and prognosis. They can accurately be measured with CMR within a single examination when normally different techniques are needed.