Two-dimensional speckle tracking echocardiography assessed right ventricular function and exercise capacity in pre-capillary pulmonary hypertension

Abstract

Resting two-dimensional speckle tracking echocardiography (2D-STE) identified right ventricular (RV) systolic function were reported to predict exercise capacity in pulmonary hypertension (PH) patients, but little attention had been payed to 2D-STE detected RV diastolic function. Therefore, we aim to elucidate and compare the relations between 2D-STE identified RV diastolic/systolic functions and peak oxygen consumption (PVO2) determined by cardiopulmonary exercise testing (CPET) in pre-capillary PH. 2D-STE was performed in 66 pre-capillary PH patients and 28 healthy controls. Linear correlation and multivariate regression analyses were performed to evaluate and compare the relations between RV 2D-STE parameters and PVO2. Receiver operating characteristic curves were used to compare the predictive value of 2D-STE parameters in predicting the cut-off—PVO2\u2009<\u200911\xa0ml/min/kg. There were significant differences of all the 2D-STE parameters between PH patients and healthy controls. In patients, RV-peak global longitudinal strain (GLS, rs\u2009=\u2009−\u20090.498, P\u2009<\u20090.001), RV- peak systolic strain rate (GSRs, rs\u2009=\u2009−\u20090.537, P\u2009<\u20090.001) and RV- peak early diastolic strain rate (GSRe, rs\u2009=\u20090.527, P\u2009<\u20090.001) significantly correlated with PVO2, but no significant correlation was observed between RV- peak late diastolic strain rate (GSRa, rs\u2009=\u20090.208, P\u2009=\u20090.093) and PVO2. The first multivariate regression analysis of clinical data without echocardiographic parameters identified WHO functional class, NT-proBNP and BMI as independent predictors of PVO2 (Model-1, adjusted r2\u2009=\u20090.421, P\u2009<\u20090.001); Then we added conventional echocardiographic parameters and 2D-STE parameters to the clinical data, identified S,(Model-2,adjusted r2\u2009=\u20090.502, P\u2009<\u20090.001), RV-GLS (Model-3, adjusted r2\u2009=\u20090.491, P\u2009<\u20090.001), RV-GSRe (Model-4, adjusted r2\u2009=\u20090.500, P\u2009<\u20090.001) and RV-GSRs (Model-5, adjusted r2\u2009=\u20090.519, P\u2009<\u20090.001) as independent predictors of PVO2, respectively. The predictive power was increased, and Model-5 including RV-GSRs showed the highest predictive capability. ROC curves found RV-GSRs expressed the strongest predictive value (AUC\u2009=\u20090.88, P\u2009<\u20090.001), and RV-GSRs\u2009>\u2009−\u20090.65/s had a 88.2% sensibility and 82.2% specificity to predict PVO2\u2009<\u200911\xa0ml/min/kg. 2D-STE assessed RV function improves the prediction of exercise capacity represented by PVO2 in pre-capillary PH.Graphical abstract