Background: Tricuspid valve annular systolic excursion (TAPSE)/pulmonary artery acceleration time (PAAT) has been suggested as an estimate of right ventricular (RV) to pulmonary artery (PA) coupling ratio in pulmonary hypertension (PH). The aim of this study is to evaluate TAPSE/PAAT ratio between normal controls and pediatric PH patients and to correlate this ratio with invasive hemodynamics to evaluate the severity of PH.
Methods: Normal controls and PH patients underwent two-dimensional echocardiography from 2014-2016. PH patients underwent right heart catheterization within 6 months of echocardiograms. PAAT and TAPSE were measured with 3 cardiac cycles and averaged. Student t-test of TAPSE/PAAT were performed between the groups. Correlations were performed with this ratio and invasive hemodynamics.
Results: Forty controls were compared to 96 PH patients. There were no significant differences of this ratio between controls and PH patients (0.01±0.005 vs 0.01±0.1, p=0.53). There were statistically significant but weak correlations between this ratio to systolic pulmonary artery pressure (r= 0.44, p<0.001), mean pulmonary artery pressure (r=0.42, p<0.001), pulmonary vascular resistance index (PVRi) (r=0.38, p=0.003), and PVRi/systemic vascular resistance index (r=0.29, p=0.006).
Conclusions: TAPSE/PAAT can not be used as a reliable measure of RV-PA coupling ratio as it is not statistically different between controls and PH patients. There is weak correlation between this ratio to invasive hemodynamics thus cannot be used as a reliable measure of severity of PH.