Isolated functional tricuspid regurgitation: how to define patients at risk for event?

Abstract

Aims: Functional tricuspid regurgitation (TR) is a turning point in cardiac diseases. Symptoms typically appear late. The optimal timing for proposing a valve repair remains a challenge. We sought to analyse the characteristics of right heart remodelling in patients with significant functional TR to identify the parameters that could be used in a simple prognostic model predicting clinical events. Methods and results: We designed a prospective observational French multicentre study including 160 patients with significant functional TR (effective regurgitant orifice area > 30 mm2) and left ventricular ejection fraction > 40%. Clinical, echocardiographic, and electrocardiogram data were collected at baseline and at the 1 and 2 year follow-up. The primary outcome was all-cause death or hospitalization for heart failure. At 2 years, 56 patients (35%) achieved the primary outcome. The subset with events showed more advanced right heart remodelling at baseline, but similar TR severity. Right atrial volume index (RAVI) and the tricuspid annular plane systolic excursion to systolic pulmonary arterial pressure (TAPSE/sPAP) ratio, reflecting right ventricular–pulmonary arterial coupling, were 73 mL/m2 and 0.40 vs. 64.7 mL/m2 and 0.50 in the event vs. event-free groups, respectively (both P < 0.05). None among all the clinical and imaging parameters tested had a significant group × time interaction. The multivariable analysis leads to a model including TAPSE/sPAP ratio > 0.4 (odds ratio = 0.41, 95% confidence limit 0.2 to 0.82) and RAVI > 60 mL/m2 (odds ratio = 2.13, 95% confidence limit 0.96 to 4.75), providing a clinically valid prognostic evaluation. Conclusions: RAVI and TAPSE/sPAP are relevant for predicting the risk for event at 2 year follow-up in patients with an isolated functional TR.