Right ventricular strain related to pulmonary artery pressure predicts clinical outcome in patients with pulmonary arterial hypertension.

ABSTRACT

AIMS: In pulmonary arterial hypertension (PAH), the right ventricle (RV) is exposed to an increased afterload. In response, RV mechanics are altered. Markers which would relate RV function and afterload could therefore aid to understand this complex response system and could be of prognostic value. The aim of our study was to (i) assess the RV-arterial coupling using ratio between RV strain and systolic pulmonary artery pressure (sPAP), in patients with PAH, and (ii) investigate the prognostic value of this new parameter over other echocardiographic parameters. METHODS AND RESULTS: Echocardiograms of 65 pre-capillary PAH patients (45 females, age 61 ± 15 years) were retrospectively analysed. Fractional area change (FAC), sPAP, tricuspid annular plane systolic excursion, and RV free-wall (FW) longitudinal strain (LS) were measured. A primary endpoint of death or heart/lung transplantation described clinical endpoint. Patients who reached a clinical endpoint had worse functional capacity (New York Heart Association), reduced RV function, and higher sPAP. Left ventricle function was similar in both groups. Only RVFW LS/sPAP ratio was found as an independent predictor of clinical endpoint in multivariable analysis (hazard ratio 8.3, 95% confidence interval 3.2-21.6, P < 0.001). The RWFW LS/sPAP (cut-off 0.19) demonstrated a good accuracy for the prediction of reaching the clinical endpoint, with a sensitivity of 92% and specificity of 82.5%. CONCLUSION: RVFW LS/sPAP ratio significantly predicts all-cause mortality and heart-lung transplantation, and was superior to other well-established parameters, in patients with pre-capillary PAH. We therefore propose RVFW LS/sPAP as a new prognostic echocardiographic marker.