Right ventricular-pulmonary arterial coupling in transcatheter structural heart interventions

Right ventricular-pulmonary arterial (RV-PA) coupling describes the interaction between right ventricular contractility and pulmonary arterial afterload, offering a comprehensive assessment of right heart function. In the context of structural heart interventions such as transcatheter aortic valve implantation (TAVI), transcatheter edge-to-edge mitral repair (TEER), and transcatheter tricuspid therapies, RV-PA coupling has emerged as a powerful prognostic indicator. Impaired coupling, typically defined using echocardiographic surrogates such as the tricuspid annular plane systolic excursion (TAPSE)/pulmonary artery systolic pressure (PASP) ratio, is consistently associated with increased mortality and heart failure hospitalization. RV-PA coupling also demonstrates dynamic behavior, with potential for improvement following intervention-though persistent uncoupling portends worse outcomes. Despite its clinical promise, significant limitations exist. Commonly used non-invasive indices, while practical, only moderately correlate with gold-standard invasive pressure-volume loop assessments and are subject to measurement variability and lack of standardization. Furthermore, current surrogates do not distinguish between the underlying drivers of uncoupling-whether impaired contractility or increased afterload-each with distinct therapeutic implications. As structural heart interventions expand to broader patient populations, a more refined understanding of RV-PA coupling may enhance risk stratification, procedural planning, and long-term management. Future research should focus on standardizing assessment techniques and establishing evidence-based thresholds to support its routine clinical use.