Velocity Vector Imaging to Assess Longitudinal Wall Motion of Adult Carotid Arteries

Biomechanical properties of the ascending aorta in patients with arterial hypertension by velocity vector imaging

Aortic stiffness is an important risk factor for cardiovascular events and morbidity. Increased aortic stiffness is associated with an increase in cardiac and vascular hypertension-related organ damage. To evaluate the biomechanical properties of the ascending aorta (AA) in patients with arterial hypertension (AH) by velocity vector imaging (VVI). Ninety-five patients with AH and 53 normal healthy control participants were prospectively enrolled. AA biomechanical properties, i.e., ascending aortic global longitudinal strain (ALS), ascending aortic global circumferential strain (ACS), and fractional area change (FAC), were evaluated by VVI. Relative wall thickness (RWT) and left ventricular mass (LVM) were calculated. Pulsed Doppler early transmitral peak flow velocity (E), early diastolic mitral annular velocity (e'), left ventricular global longitudinal strain (GLS), distensibility (D) and stiffness index (SI) of AA were also obtained. The ALS, ACS and FAC were significantly lower in the AH patients, especially in those with ascending aorta dilatation (AAD), than in the normal healthy control subjects. The patients with AAD had a higher E/e' ratio, RWT, LVM and SI and a lower GLS and D than patients without AAD and normal healthy volunteers (p < 0.05). There were significant associations between biomechanical properties and D, SI, E/e' and GLS (ALS and D: r = 0.606, ALS and SI: r = - 0.645, ALS and E/e': r = - 0.489, ALS and GLS: r = 0.466, ACS and D: r = 0.564, ACS and SI: r = - 0.567, ACS and E/e': r = - 0.313, ACS and GLS: r = 0.320, FAC and D: r = 0.649, FAC and SI: r = - 0.601, FAC and E/e': r = - 0.504, FAC and GLS: r = 0.524, respectively, p < 0.05). The biomechanical properties of AA were impaired in patients with AH, especially patients with ascending aorta dilatation. Hypertension is associated with a high prevalence of diastolic and systolic dysfunction and increased arterial stiffness. Further study is needed to evaluate the clinical application of AA biomechanical properties by VVI.

Pulmonary Artery Strain Predicts Prognosis in Pulmonary Arterial Hypertension

BACKGROUND

Current cardiac magnetic resonance (CMR) imaging in pulmonary arterial hypertension (PAH) focuses on measures of ventricular function and coupling.

OBJECTIVES

The purpose of this study was to evaluate pulmonary artery (PA) global longitudinal strain (GLS) as a prognostic marker in patients with PAH.

METHODS

The authors included 169 patients with PAH from the ASPIRE (Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre) and INITIATE (Integrated computatioNal modelIng of righT heart mechanIcs and blood flow dynAmics in congeniTal hEart disease) registries, and 82 normal controls with similar age and gender distributions. PA GLS was derived from CMR feature tracking. Right ventricular measurements including volumes, ejection fraction, and right ventricular GLS were also derived from CMR. Patients were followed up a median of 34 months with all-cause mortality as the primary endpoint. Other known risk scores were collected, including the REVEAL (Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management) 2.0 and COMPERA (Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension) 2.0 scores.

RESULTS

Of 169 patients (mean age: 57 ± 15 years; 80% female), 45 (26.6%) died (median follow-up: 34 months). Mean PA GLS was 23% ± 6% in normal controls and 10% ± 5% in patients with PAH (P < 0.0001). Patients with PA GLS <9% had a higher risk of mortality than those with PA GLS ≥9% (P < 0.001), and this was an independent predictor of mortality in PAH on multivariable analysis after adjustment for known risk factors (HR: 2.93; P = 0.010). Finally, in patients with PAH, PA GLS provided incremental prognostic value over the REVEAL 2.0 (global chi-square; P = 0.001; C statistic comparison; P = 0.030) and COMPERA 2.0 (global chi-square; P = 0.001; C statistic comparison; P = 0.048).

CONCLUSIONS

PA GLS confers incremental prognostic utility over the established risk scores for identifying patients with PAH at higher risk of death, who may be targeted for closer monitoring and/or intensified therapy.