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

Abstract

Introduction: Feature tracking is a new technique allowing measurement of right ventricular strains and strain rates from 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 Chronic Thromboembolic Pulmonary Hypertension (CTEPH). Methods: Thirteen patients with CTEPH were assessed by right heart catheterization (RHC) and cardiac MRI, including standard cine acquisitions. Global right ventricular longitudinal, circumferential and radial strain and strain rates were correlated with the mean pulmonary artery pressure (mPAP). Systolic, E and A decelerations (corresponding 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) (Figure). Results: The mPAP was 30.3±15.2mmHg. Feature tracking was successful in all the patients, but in 2 patients, it was not possible to separate the E and A waves. 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. 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 suggests a strong potential of feature tracking MRI to diagnose and monitor patients with pulmonary hypertension.