Non-invasive right ventriculo-arterial coupling as a rehospitalization predictor in dilated cardiomyopathy: A comparison of five different methods

Background: Right ventricular (RV) pulmonary artery coupling (RVPAC) is a predictor of outcome in left-sided heart failure (HF). Several echocardiographic estimates for RVPAC have been proposed. Aims: This study aimed to compare multiple non-invasive methods to calculate RVPAC and to assess its prognostic role in patients with dilated cardiomyopathy (DCM). Methods: We prospectively enrolled 60 stable patients with DCM. RVPAC was estimated using five methods: as the tricuspid annular plane excursion/pulmonary artery systolic pressure (PASP) ratio; as the RV global longitudinal strain/PASP ratio; as the RV free wall strain (RVFW-LS)/PASP ratio; as the three-dimensional (3D) RV ejection fraction (RVEF)/PASP ratio; and as the 3D RV stroke volume (SV)/end-systolic volume (ESV) ratio. Patients were followed for a mean period of 18 (9) months for the endpoint of HF rehospitalizations. Results:Twenty-nine patients (48%) reached the endpoint. All RVPAC estimates were more impaired in those patients reaching the endpoint (P <0.001 for all) and all predicted rehospitalizations in un-adjusted analysis. RVFW-LS/PASP and RVEF/PASP remained independent predictors of events, after adjustment for clinical and echocardiographic confounders. Using cut-offs obtained from receiver operating characteristic (ROC) analysis, we found that patients with RVFW-LS/PASP >-0.40 and patients with RVEF/PASP <1.30 had a higher risk of HF rehospitalization (log-rank P = 0.001 and P = 0.002, respectively). Conclusion: RVFW-LS/PASP and RVEF/PASP as non-invasive estimates of RVPAC are independent predictors of HF rehospitalization in patients with DCM.