Right ventricle to pulmonary artery coupling as a prognostic factor in tricuspid regurgitation: A systematic review

Severe tricuspid regurgitation is a prevalent condition with a poor prognosis. Recent advances in transcatheter techniques resulted in a growing population of patients who are qualified for transcatheter edge-to-edge repair of tricuspid regurgitation. There is evidence that these procedures result in an improvement in heart failure symptoms and patient-reported quality of life; however, the data guiding the qualification process are scarce. The increasing volume of patients that undergo qualification for interventional TR treatment creates the need to improve the tools for risk stratification and outcome prediction. TAPSE/SPAP ratio is an echocardiographic parameter that has been recently proposed as a predictive factor for adverse outcome in various clinical settings including patients undergoing transcatheter procedures. In this systematic review, we gathered the data on the utility of this parameter in patients with significant tricuspid regurgitation. We identified five studies fulfilling the search criteria. In all of the studies, a low TAPSE/SPAP ratio was associated with worse prognosis, but the exact cutoff value remains difficult to define. In available studies, it ranged from 0.26 to 0.49 mm/mmHg. Moreover, greater severity of tricuspid regurgitation results in an underestimation of SPAP potentially reducing the usefulness of TAPSE/SPAP ratio in patients with massive and torrential TR.