Objective To explore the significance of right ventricular function in predicting prognosis in patients after pneumonectomy for non-small cell lung cancer(NSCLC).Methods 285 patients after pneumonectomy for NSCLC admitted to Chongqing Hospital of Traditional Chinese Medicine from August 2020 to August 2023 were selected as study subjects retrospectively.In this study,right ventricular-pulmonary artery(RV-PA)coupling was assessed non-invasively using the ratio of transthoracic echocardiographically derived tricuspid annular plane systolic excursion(TAPSE)to pulmonary artery systolic pressure(PASP)and right ventricular function was assessed using RV-PA coupling.The patients were divided into two groups based on the cutoff value of RV-PA uncoupling derived from the spline analysis,RV-PA coupling group(TAPSE/PASP≥0.66 mm/mmHg,n=138),and RV-PA uncoupling group(TAPSE/PASP＜0.66 mm/mmHg,n=147).The cumulative survival rates were estimated with Kaplan-Meier curves.Risk factors independently associated with all-cause mortality were assessed by Cox regression analysis.Results Patients in the RV-PA uncoupling group had significantly lower cumulative survival rates(P＜0.001).Clinical stage IV peak tricuspid regurgitation velocity,and RV-PA uncoupling all maintained independent correlations with all-cause mortality(P＜0.005).Conclusions Early assessment of right ventricular function in patients after pneumonectomy for NSCLC is important for corrective treatment of high-risk patients to improve their prognosis.