P212 MRI derived global right ventricle diastolic strains correlate with mPAP in CTEPH patients

Abstract

Introduction: Feature tracking is a new technique allowing measurement of right ventricular strains and strain rates from cardiac cine magnetic resonance imaging (MRI), based on the detection of image pattern motion during the cardiac cycle. This present work uses feature tracking MRI to investigate the modification of the right ventricle diastolic function in patients with Chronic Thromboembolic Pulmonary Hypertension (CTEPH). Methods: Thirteen patients with suspected CTEPH were assessed by right heart catheterization (RHC) and cardiac MRI, including standard cine acquisitions during breath-hold. 4C, right and left 2C and short-axis views were used for feature tracking analysis. Global right ventricular longitudinal, circumferential and radial strain and strain rates were correlated with the mean pulmonary artery pressure (mPAP) measured during the RHC. Systolic, E and A decelerations (corresponding respectively to the early diastolic filling and to the atrial contraction) were measured from the descending slopes of the global longitudinal strain rates (in %.ms-2) (Figure1). Results: CTEPH was confirmed in 11 / 13 patients. The mPAP was 30.3 ± 15.2 mmHg (11-66 mmHg). Feature tracking was successful in all the patients, but in 2 patients (further excluded from the analysis) it was not possible to separate the E and A waves. Representative examples of peak strain maps and curves of the right ventricle are shown in Figures 1 and 2. Peak diastolic circumferential strain rate (R2=0.58, p = 0.01) and the E deceleration (R2=0.48, p=0.03) but not systolic strain indices were significantly correlated with mPAP. Discussion and conclusion: The correlation between the RV diastolic function and the mPAP in CTEPH patients could reflect subclinical compensatory hypertrophy of the RV wall following chronic pressure overload. This study suggests a strong potential of feature tracking cardiovascular MRI to diagnose and monitor patients with pulmonary hypertension.Figure 2Examples of global right ventricular longitudinal strain and strain rate in patients with a normal pulmonary pressure (upper row) and with a mild pulmonary hypertension (lower row). The strain rate curves demonstrated clearly the S (systolic), E (early) and A (atrial) waves with the corresponding decelerating slopes (in red).View Large Image Figure ViewerDownload Hi-res image Download (PPT)