Echocardiographic estimation of right ventricular wall tension: haemodynamic comparison and long-term follow-up

Prognosis in pulmonary hypertension is strictly linked to right ventricle failure, which results from uncoupling between right ventricle function and its afterload. This study sought to describe how to estimate with echocardiography right ventricular wall tension, its correlation with right ventricle haemodynamics and its prognostic role. A total of 190 patients without overt right ventricle failure but with suspected pulmonary hypertension on a previous echocardiogram underwent right heart catheterization and nearly-simultaneous echocardiography. Right ventricular wall tension was estimated according to Laplace's law as right ventricle length × tricuspid regurgitation peak gradient and it was correlated with right ventricle haemodynamic profile; its potential prognostic impact was tested along with canonical right ventricle function parameters. Right ventricular wall tension correlated significantly with invasive estimation of right ventricle end-diastolic pressure (R: 0.343, p < 0.001) and with several other haemodynamic variables, such as mean pulmonary artery pressure, pulmonary artery compliance, transpulmonary gradient, pulmonary vascular resistance, right atrial pressure and right ventricle stroke work index (all p < 0.001). At a mean follow-up of five years and three months, only right ventricular wall tension was associated to all-cause mortality (p = 0.036), while tricuspid annular plane systolic excursion (p = 0.536), right ventricle fractional area change (p = 0.383), right ventricle fractional area change (p = 0.076), tricuspid regurgitation peak gradient (p = 0.107) and tricuspid annular plane systolic excursion/tricuspid regurgitation peak gradient (p = 0.181) could not. We identified a novel bedside echocardiographic predictor of altered right ventricle haemodynamics, which is precociously altered in patients without overt right ventricle failure and is associated to all-cause mortality at a long-term follow-up. Further studies are needed to confirm its role in pulmonary hypertension patients.