Right ventricular systolic dysfunction in patients with severe ischemic cardiomyopathy - CMR insights into an interventricular relationship

Abstract

Background Right ventricular systolic dysfunction is associated with worsened outcomes and poor survival in patients with heart failure. However, it is unclear what mechanisms, other than the presence of RV infarction, contribute to the development of RV dysfunction in patients with severe ischemic cardiomyopathy. We sought to determine the impact of baseline demographic variables, CAD severity, LV diastolic function assessed by echocardiography, ventriculovascular coupling, LV remodeling, aortic biomechanical properties, and RV infarction, assessed by CMR, on RV ejection fraction. Methods Patients were selected if they had undergone TTE and CMR studies within 7 days (median=1 day). 354 patients with LVEF ≤ 40% and ≥ 70% stenosis in ≥1 coronary artery but without prior mitral valve surgery, fused E/A waves, atrial fibrillation or > moderate mitral regurgitation were included. Of those, 30 patients were excluded due to suboptimal CMR image quality for adequate RV volume tracings. A total 324 charts were reviewed for demographic and laboratorial data. Diastolic function assessment was performed as per guidelines. Aortic biomechanics were measured using previously validated software (ARTFUN, INSERM U678, Paris, France) using semi-automated tracing of aortic contours with phasecontrast images and through-plane velocity encoding of the ascending and descending aorta. CMR evaluation also included long and short axis assessment of LV/RV function respectively on balanced steady state free precession images along with assessment of LV/RV myocardial scar (on phase-sensitive inversion recovery DHE-CMR sequence ~ 10-20 minutes). Multivariate linear regression analysis performed to identify the independent predictors of RVEF. Results