Prognostic Value of Right Atrial Adverse Remodeling in Patients With Pulmonary Arterial Hypertension

Assessment of right atrial (RA) structure helps monitor right heart (RH) function, critical for prognosis in pulmonary arterial hypertension (PAH). This study aims to assess the prognostic value of RA adverse remodeling (RAAR) with targeted therapy in PAH. Patients diagnosed with PAH between June 2013 and June 2024 were prospectively recruited. Right atrial reverse remodeling (RAAR) was defined by the relative change in right atrial diameter (RAD) on 1-year follow-up echocardiography (ECHO). RAAR was defined as a RAD decrease of < 13% or any increase from baseline, as determined by receiver operating characteristic curve analysis. The primary composite endpoint included heart failure-related readmission, all-cause mortality, and lung transplantation. Of 240 patients enrolled, 234 completed 1-year follow-up, with a median follow-up duration of 37.5 months (interquartile range: 23.3-57.5 months). RAAR was observed in 168 patients (71.8%), and baseline RAD was its sole independent predictor (OR 0.941, p = 0.012). RAAR was associated with significantly poorer event-free survival in both the low-risk group (log-rank p = 0.037) and the intermediate-/high-risk group (log-rank p < 0.001). Adding RAAR improved the ESC model (χ²: 18.08-21.83) and the three-strata COMPERA model (χ²: 22.65-28.04). These findings suggest that RAAR is a key indicator for evaluating prognosis in PAH patients, holding promise for reflecting treatment response and predicting clinical outcomes in PAH.