Role of anatomical regurgitant orifice area and right ventricular contractile reserve in severe tricuspid regurgitation

Aims We sought to propose a novel risk stratification system for severe tricuspid regurgitation (TR) using 3D-anatomical regurgitant orifice area (3D-AROA) and the slope of tricuspid annular plane systolic excursion vs. systolic pulmonary artery pressure (TAPSE/SPAP) and to validate its prognostic significance. Methods and results Sixty-four patients with severe functional TR (52% torrential) underwent 3D echocardiography and exercise-stress echocardiography. As an estimate of regurgitation severity, 3D-AROA was measured with the customized software package. As an index of right ventricular (RV) contractile reserve, the TAPSE/SPAP slope was calculated by plotting the relationship between TAPSE and SPAP during exercise test. Haemodynamic parameters were obtained by right heart catheterization (RHC). Based on receiver operating characteristics curves, optimal cut-off values of 3D-AROA and TAPSE/SPAP slope to identify all-cause mortality were 161mm(2) and 0.046 mm/mmHg, respectively. During a median follow-up of 559 days, 20 patients (31%) died. After correcting for potential confounders, 3DAROA >= 161mm(2) (HR 4.37; 95% CI 1.34-14.07; P = 0.015) and TAPSE/SPAP slope <= 0.046mm/mmHg (HR 4.76; 95% CI 1.46-15.53; P = 0.009) were echocardiographic parameters independently associated with all-cause mortality. The cumulative survival rate was lower in patients with 3D-AROA >= 161mm(2) and TAPSE/SPAP slope <= 0.046mm/mmHg compared with their counterparts (both P<0.05). RHC confirmed higher right atrial pressure (P<0.001) and lower cardiac index (P = 0.004) in patients with both 3D-AROA >= 161mm(2) and TAPSE/SPAP slope <= 0.046mm/mmHg. Conclusion Large AROA and reduced RV contractile reserve during exercise are independently associated with poor prognosis. The new grading scheme of severe TR was validated by haemodynamics and may improve risk stratification. [GRAPHICS] .

Automated summary

This study proposed a novel risk stratification system for severe tricuspid regurgitation and validated its prognostic significance. The findings showed that a large 3D-AROA and reduced right ventricular contractile reserve during exercise were independently associated with poor prognosis.