Association with outcomes of the planimetry of vena contracta area by 3-dimensional color Doppler echocardiography in patients with secondary tricuspid regurgitation

Abstract Background The cut-off value for defining severe secondary tricuspid regurgitation (STR) using the planimetry of color Doppler three-dimensional echocardiography (3DE) vena contracta area (VCA) has been determined in previous studies based on its correlation with the values of the effective regurgitant orifice area (EROA), obtained using the proximal isovolumic surface area (PISA) method, in patients with severe STR. However, the association of VCA with outcomes has not been examined in these studies. Purpose We sought to 1) identify the cut-off value of 3DE VCA associated with an increased risk of death for any cause or heart failure hospitalizations (HF) in patients with STR; 2) test if the planimetry of 3DE VCA may improve the risk stratification over the quantitative parameters of STR severity. Methods Retrospective analysis of patients with STR consecutively enrolled in the FUTURE 3DECHO study who had good quality 3DE dataset for VCA planimetry. Results We selected 184 patients (76±13 years, 43% women). According to the guideline-recommended multiparametric approach, 15% of the patients had mild, 51% moderate, 22% severe, and 12% massive STR. The mean 3DE VCA was 0.72±0.41 cm2 and it increased significantly with the severity of STR. Among all the quantitative parameters of STR severity, the strongest correlation of 3DE VCA was found with EROA by PISA (Spearman: 0.63, p < 0.001). Using spline curve analysis, a 3DE VCA of 0.65 cm2 was identified as the threshold value associated with increased risk of experiencing the composite endpoint in the whole population (Figure 1A). At univariate analysis, a 3DE VCA > 0.65 cm2 carried a 4-fold increased risk of combined events and it also stratified the risk in patients with EROA < 0.4 cm2 (Figure 1B). When added to a multivariable model including right atrial volume, right ventricular ejection fraction, pulmonary arterial systolic pressure, STR EROA and regurgitant volume, VCA increased significantly the predictive power of the model and mainteined its independent correlation with outcomes (HR: 1.011, CI 95%: 1.003-1.019, P=0.007; X2 of models: 44 vs 39, p value <0.001) (Figure 2). Conclusion 3DE VCA has independent and incremental value over the other parameters of severity for predicting the risk of events in patients with STR. 3DE VCA> 0.65 cm2 identified STR patients with EROA< 0.4 cm2 at higher risk of experiencing the composite endpoint of death and HF. Figure 1 A and B Figure 2. Cox Regression multivariate