Required temporal resolution for accurate thoracic aortic pulse wave velocity measurements by phase-contrast magnetic resonance imaging and comparison with clinical standard applanation tonometry.

BACKGROUND: Pulse wave velocity (PWV) is a biomarker for arterial stiffness, clinically assessed by applanation tonometry (AT). Increased use of phase-contrast cardiac magnetic resonance (CMR) imaging allows for PWV assessment with minor routine protocol additions. The aims were to investigate the acquired temporal resolution needed for accurate and precise measurements of CMR-PWV, and develop a tool for CMR-PWV measurements. METHODS: Computer phantoms were generated for PWV = 2-20 m/s based on human CMR-PWV data. The PWV measurements were performed in 13 healthy young subjects and 13 patients at risk for cardiovascular disease. The CMR-PWV was measured by through-plane phase-contrast CMR in the ascending aorta and at the diaphragm level. Centre-line aortic distance was determined between flow planes. The AT-PWV was assessed within 2 h after CMR. Three observers (CMR experience: 15, 4, and <1 year) determined CMR-PWV. The developed tool was based on the flow-curve foot transit time for PWV quantification. RESULTS: Computer phantoms showed bias 0.27 ± 0.32 m/s for a temporal resolution of at least 30 ms. Intraobserver variability for CMR-PWV were: 0 ± 0.03 m/s (15 years), -0.04 ± 0.33 m/s (4 years), and -0.02 ± 0.30 m/s (<1 year). Interobserver variability for CMR-PWV was below 0.02 ± 0.38 m/s. The AT-PWV overestimated CMR-PWV by 1.1 ± 0.7 m/s in healthy young subjects and 1.6 ± 2.7 m/s in patients. CONCLUSIONS: An acquired temporal resolution of at least 30 ms should be used to obtain accurate and precise thoracic aortic phase-contrast CMR-PWV. A new freely available research tool was used to measure PWV in healthy young subjects and in patients, showing low intra- and interobserver variability also for less experienced CMR observers.

Assessment of Cardiovascular Risk Factors in Patients with Psoriasis.

Psoriasis is a chronic inflammatory skin disorder associated with increased cardiovascular risk. Aim of this work was to evaluate the association between psoriasis and chosen cardiovascular risk factors, echocardiographic parameters, and carotid intima-media thickness. A total of 50 patients with psoriasis and 50 controls were enrolled in the study. Psoriasis area severity index was calculated in the study group. Systolic and diastolic blood pressure, body mass index, waist circumference, lipids, fasting glucose, and D-dimer levels were assessed in all patients. In addition, echochardiographic parameters and carotid intima-media thickness were measured. Patients with psoriasis had higher blood pressure (P=0.001), elevated triglycerides (P=0.0218), lower high-density lipoprotein cholesterol (HDL-C) (P=0.0014), elevated D-dimer levels (p=0.0009), and were more frequently overweight (P=0.0198) in comparison to controls. There were no differences in echocardiographic parameters and carotid intima-media thickness between the psoriasis and control groups. Moreover, a positive correlation between psoriasis area severity index and blood pressure was observed (P=0.0088). The study confirmed that psoriasis is associated with increased cardiovascular risk. The association between psoriasis, intima-media thickness, and echocardiographic parameters should be evaluated in large prospective studies.