Prognostic value of right atrial adverse remodeling in patients with pulmonary arterial hypertension

Purpose 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. Methods 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). Receiver operating characteristic (ROC) curve analysis identified the optimal RAD change threshold for RAAR. Clinical outcomes were further compared using Cox regression and Kaplan–Meier analysis. The primary composite endpoint included heart failure related readmission, all-cause mortality, and lung transplantation. Results A total of 240 patients with PAH receiving targeted therapy were prospectively enrolled, with a median follow-up duration of 37.5 months (interquartile range: 23.3–57.5 months). Among them, 234 completed 1-year ECHO follow-up. RAAR was defined as a RAD decrease <13% or any increase from baseline, identifying 168 patients (71.8%) with RAAR. Baseline RAD was the only independent predictor of RAAR (OR 0.941, p=0.012). Patients with RAAR had significantly worse clinical outcomes (log-rank p=0.004; Breslow p=0.021). RAAR was an independent prognostic factor for composite endpoints (HR 2.104, 95% CI 1.045-4.235, p=0.037) by multivariable Cox regression analysis. Conclusions RAAR is a key indicator for evaluating prognosis in patients with PAH. RAAR holds promise for reflecting treatment response and predicting clinical outcomes in PAH.