Pulmonary arterial hypertension: right ventricular phenotyping to improve risk assessment at follow-up

Background and Aims The aim of this study was to evaluate whether echocardiography-derived phenotypes describing different degrees of right ventricular (RV) remodelling and dysfunction add prognostic information to that of current risk stratification tools in patients with pulmonary arterial hypertension (PAH) at first follow-up.Methods In 11 centres of the Italian Pulmonary Hypertension NETwork (IPHNET), data were prospectively collected from patients with PAH who underwent re-evaluation between 6 and 12 months after diagnosis. Echocardiographic variables were combined a priori to define four phenotypes representing different degrees of RV dilatation and right ventricular-pulmonary arterial (RV-PA) coupling: a mildly dilated right ventricle with preserved RV-PA coupling defined phenotype-1; a mildly dilated right ventricle with poor RV-PA coupling defined phenotype-2; a severely dilated right ventricle with preserved RV-PA coupling defined phenotype-3; a severely dilated right ventricle with poor RV-PA coupling, either with or without tricuspid regurgitation of moderate degree or more, defined phenotype-4. Patients were followed up for all-cause death for a median of 3.7 years.Results These echocardiographic phenotypes were present in all European Society of Cardiology/European Respiratory Society or REVEAL 2.0 risk groups except for the high-risk groups, which included only phenotype-3 and phenotype-4. In each risk group, RV phenotype-4 identified patients with a poorer prognosis; RV phenotype-1 identified patients with better survival in intermediate risk groups.Conclusions Echocardiography-derived phenotypes describing different degrees of RV remodelling and dysfunction provide prognostic information which is independent of and additional to the clinically defined risk in PAH patients at first follow-up.