Right ventricular dyssynchrony predicts clinical outcomes in patients with pulmonary hypertension

RV dyssynchrony has been described in patients with pulmonary hypertension (PH) and is an independent predictor of clinical worsening; however, the optimal method for measuring RV dyssynchrony has not been fully established. This study aimed to investigate whether RV dyssynchrony is correlated with hemodynamics and prognosis in PH patients and to identify the best parameter for evaluating RV dyssynchrony.

This study assessed 100 PH patients, measuring mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), and cardiac index (CI) by right heart catheterization (RHC). RV strain curves were obtained using two-dimensional speckle-tracking echocardiography (2DSTE), and time from QRS onset to maximum peak longitudinal strain (T_max) or time to first peak (T_first) was measured. Difference in time between the earliest and the latest segment (TD) and standard deviation (SD) of T in 6 segments with RV apex (-SD6) and 4 segments without RV apex (-SD4) were also assessed.

Among all RV dyssynchrony parameters, T_max-SD6 showed the strongest correlation with RV hemodynamics such as mPAP (R²=0.27, P<0.0001) and PVR (R²=0.22, P<0.0001). Univariate and multivariate Cox proportional hazard analyses showed that T_max-SD6 significantly correlated with and independently predicted event-free survival in patients with PH.

RV dyssynchrony is a useful index for RV function and an independent predictor of clinical outcomes in patients with PH. In addition, the inclusion of apical motion is essential for the optimal assessment of RV dyssynchrony.