Right ventricular (RV) systolic dysfunction and pulmonary hypertension are associated with mortality in adults with coarctation of aorta (COA). The tricuspid annular plane systolic excursion/RV systolic pressure (TAPSE/RVSP) ratio is a validated noninvasive tool for the assessment of RV-pulmonary arterial (RV-PA) coupling in patients with PA hypertension, but similar data are lacking in adults with COA. The purpose of this study was to assess the relationship between the TAPSE/RVSP ratio and outcomes in this population. A retrospective cohort study of adults with repaired COA was performed. RV systolic dysfunction was defined as RV free wall strain ≥-24% at baseline, whereas new-onset RV systolic dysfunction was defined RV free wall strain ≥-24% during follow-up. Of 661 patients, TAPSE, RVSP, and TAPSE/pulmonary artery systolic pressure ratio were 22 ± 6 mm, 34 ± 12 mm Hg, and 0.71 (0.48-0.89) mm/mm Hg, respectively. Of 661 patients, 152 (23%) had RV systolic dysfunction at baseline, and TAPSE/RVSP <0.43 mm/mm Hg was the optimal threshold to detect RV systolic dysfunction. TAPSE/RVSP <0.43 mm Hg was associated with RV systolic dysfunction (adjusted odds ratio: 3.11 [1.83-6.19], P = 0.004). Of 509 patients with normal RV systolic function, 42 (8%) and 36 (7%) developed new-onset RV systolic dysfunction and new-onset right heart failure, respectively, during follow-up. TAPSE/RVSP <0.43 mm/mm Hg was associated with new-onset RV systolic dysfunction (adjusted hazard ratio: 1.95 [1.46-2.77], P = 0.008) and new-onset right heart failure (adjusted hazard ratio: 0.81 [0.68-0.92], P = 0.005). The TAPSE/RVSP ratio can potentially be used to identify patients at risk for new-onset RV systolic dysfunction and right heart failure and provide opportunity for proactive interventions to prevent adverse outcomes.