Quantification of biventricular strain and assessment of ventriculo–ventricular interaction in pulmonary arterial hypertension using exercise cardiac magnetic resonance imaging and myocardial feature tracking

Abstract

Background Right ventricular (RV) failure is the main cause of mortality in pulmonary arterial hypertension (PAH). Exercise testing helps identify early RV maladaptation and systolic dysfunction and facilitates therapy. Myocardial strain has been shown to be more sensitive than ejection fraction (EF) in detecting subclinical ventricular contractile dysfunction. Chronic pressure overload in PAH had been associated with changes in left ventricular (LV) filling. Purpose To compare biventricular strains and ventriculo–ventricular interaction in PAH and controls using cardiac magnetic resonance feature tracking (cMRI‐FT) and to determine the reproducibility of strain analysis. Study Type Prospective. Population Nine PAH and nine control subjects. Field Strength/Sequence 1.5T MRI balanced steady state free precession. Assessment RV and LV longitudinal strain (EllRV and EllLV) were derived using the mid‐axial images. Radial (ErrLV) and circumferential strain (EccLV) were derived using the mid‐ventricular short‐axis images. Relationships between strain and volumetric parameters were assessed at rest and during submaximal in‐magnet exercise. Statistical Tests Comparison of rest‐to‐exercise data between PAH and controls was analyzed using two‐way repeated measures analysis of variance. The relationship between volumetric parameters and cMRI‐FT were assessed using Pearson's correlation. Reproducibility was assessed by using Bland–Altman plots. Results PAH had significantly lower EllRV at rest (−16.6 ± 2.7 vs. −20.1 ± 3.6, P = 0.03) despite normal RVEF. During exercise, RV systolic contractile reserve measured by EllRV was significantly reduced in PAH (PInteraction = 0.02). In PAH, indexed RV end‐systolic volume (ESVi) significantly correlated with EccLV and ErrLV at rest (r = −0.65 and r = −0.70, P < 0.05) and with ErrLV during exercise (r = −0.43, P < 0.05). High observer agreement was demonstrated. Data Conclusion Despite normal resting RVEF, RV systolic function and contractile reserve as measured by EllRV was significantly reduced in PAH. The close relation between RVESVi with EccLV and ErrLV provides evidence of systolic ventriculo–ventricular interaction in PAH. Exercise cMRI‐FT may provide a quantitative metric for detection of subclinical RV dysfunction in PAH. Level of Evidence: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:1427–1436.

Cardiac Magnetic Resonance in Pulmonary Hypertension—an Update

“…Biventricular strain is significantly impaired in PH and could assist in the early detection of right and left heart dysfunction [ 43 – 45 ]. Besides, feature tracking technology has been used to predict outcome in patients with PH.…”

Update on noninvasive imaging of right ventricle dysfunction in pulmonary hypertension

“…Multivariate logistic binary regression analysis identified long-axis RV radial strain as being able to identify RV-arterial uncoupling (102). In exercise states, PH patients showed less reserve than controls, as reflected by displaying significant decrease in longitudinal RV strain despite normal EF (103). Strain has been used in several studies of therapeutic response (104,105).…”

Numerical Simulation of the Effect of Pulmonary Vascular Resistance on the Hemodynamics of Reoperation After Failure of One and a Half Ventricle Repair

“…The model constructed in this essay is relatively simple and does not take into account the factors of interventricular interaction, valve movement and coronary circulation of the great clinical value, although it effectively captures physiological changes. Some scholars have used computational models to verify the importance of interventricular interaction (Korakianitis and Shi, 2006a;Lin et al, 2019) and valve movement (Korakianitis and Shi, 2006a). However, 1.5VR that is generally selected for patients based on their cardiac appearance is characterized by the right ventricle being much smaller than the left one, so the interventricular interaction can be ignored.…”