Prevalence and Prognostic Value of Right Ventricular–Pulmonary Artery Uncoupling in Adults with Right-Sided Congenital Heart Disease

<b>Background:</b> Right-sided congenital heart diseases (R-CHDs) are frequently associated with right ventricular (RV) dysfunction and heterogeneous clinical trajectories, underscoring the need for individualized risk assessment. RV-pulmonary artery (RV-PA) coupling has emerged as an important prognostic marker in several cardiovascular conditions. However, its role in adults with R-CHD has not been well established. <b>Methods:</b> We retrospectively reviewed consecutive adults with R-CHD evaluated at our outpatient clinic between October 2013 and November 2023. RV-PA uncoupling was defined by echocardiography as a tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP) ratio ≤0.55. The primary composite endpoint included all-cause mortality, major supraventricular and ventricular arrhythmias, unplanned cardiac hospitalizations, and need for (re)-interventions. <b>Results:</b> A total of 132 patients (mean age 41.6 ± 15.7 years; 51.5% male) were included. RV-PA uncoupling was identified in 48 patients (36.4%). Over a median follow-up of 40.3 months, the primary composite endpoint occurred in 71 patients (53.8%). Patients experiencing adverse outcomes were older and showed lower TAPSE, higher PASP, larger RV and right atrial dimensions, and a significantly higher prevalence of RV-PA uncoupling (<i>p</i> < 0.001). Multivariable Cox regression analysis demonstrated that RV-PA uncoupling was a strong independent predictor of adverse outcomes (HR 4.478, <i>p</i> < 0.001), outperforming its individual components. In addition, RV-PA uncoupling and RV mid-diameter independently predicted the need for surgical or interventional procedures during follow-up. <b>Conclusions:</b> RV-PA uncoupling provides robust and independent prognostic information in adults with R-CHD and represents a practical tool for personalized risk stratification, potentially guiding tailored surveillance strategies and timing of therapeutic interventions.