RESUMO
Objective:To evaluate the right atrial volume and function abnormalities in patients with pulmonary hypertension (PH) by four-dimensional automatic quantitation technique, and to explore the application value of this technique in evaluating the risk stratification and World Health Organization functional class(WHO-FC) of PH patients.Methods:Eighty-four adult patients with PH diagnosed by right heart catheterization from April to October 2022 in Fuwai Central China Cardiovascular Hospital were consecutively enrolled as the PH group. All cases were divided into 3 groups according to the mean pulmonary arterial pressure (mPAP): mild PH group ( n=28), moderate PH group ( n=28), severe PH group ( n=28). Twenty-eight healthy volunteers matched by gender and age were included in the same period as the control group. The volume and strain parameters of the right atrium were obtained by analyzing the four-dimensional image of the right atrium using four-dimensional automatic quantitation technique, including right atrial minimum volume index (RAVImin), right atrial maximum volume index (RAVImax), right atrial presystolic volume index (RAVIpreA), right atrial ejection fraction (RAEF), right atrial passive ejection fraction (RAPEF), right atrial active ejection fraction, RAAEF, longitudinal strains of right atrial reserve, conduit and systolic period (RASr, RAScd, RASct), circumferential strains of right atrial reserve, conduit and systolic period (RASr-c, RAScd-c, RASct-c). The differences in right atrial parameters among four groups were compared.ROC curve was used to analyze the diagnostic efficiency of right atrial four-dimensional strain parameters for PH patients with WHO-FC≥Ⅲ. Pearson linear correlation analysis was used to investigate the relationships between RASr and right atrial area (RAA), NT-proBNP and tricuspid annular plane systolic excursion to pulmonary arterial systolic pressure ratio (TAPSE/sPAP). Results:①Compared with the control group, RAEF, RAPEF, RASr, RAScd, RASr-c, RAScd-c were significantly decreased in mild, moderate and severe PH groups; while RAAEF, RASct, RASct-c were significantly increased in mild PH group and significantly decreased in moderate and severe PH groups, and the differences were statistically significant (all P<0.05). RAVImin, RAVImax, RAVIpreA gradually increased among the control, mild PH, moderate PH and severe PH groups, and the differences were statistically significant (all P<0.05). RAEF, RAPEF, RAAEF, RASr, RAScd, RASct, RASr-c, RAScd-c, RASct-c were decreased successively among mild, moderate and severe PH groups, and the differences were statistically significant (all P<0.05). ②ROC curve showed that RASr had the highest diagnostic efficiency in PH patients with WHO-FC ≥Ⅲ, and the cut-off value was 20.5% (AUC=0.914, P<0.001). ③Correlation analysis showed that RASr was correlated with RAA, NT-proBNP and TAPSE/sPAP ( r=-0.803, -0.621, 0.739; all P<0.001). Conclusions:The degree of right atrial function impairment increased in patients with mild, moderate and severe PH in turn. RASr is the best predictor of WHO-FC ≥Ⅲ in patients with pulmonary hypertension and is a potential parameter for risk stratification in patients with PH.