47 Identification of threshold values to define right chamber enlargement consistent with severe tricuspid regurgitation

Background

Right ventricle (RV), tricuspid anulus (TA) and right atrium (RA) dilatation, are listed among the supportive signs to grade severe tricuspid regurgitation (TR) according to current EACVI and ESC guidelines. However, at present, there is no cut-off value to define RV, RA and TA dilatation associated to severe TR.

Purpose

Accordingly, we sought to identify the threshold values of RV, RA and TA size associated to severe TR.

Methods

302 patients (59 ± 13 years, 54 % women) with functional TR underwent three- (3D) and two-dimensional (2D) echocardiography to obtain: 3D RV end diastolic volume (RVEDVi) indexed for body surface area (BSA), 3D RV end systolic volume indexed for BSA (RVESVi), 3D RA max volume indexed for BSA (3DRAi), 2D RA systolic volume indexed for BSA (3DRAi), 2D RV basal diameter (2DRVd), 2D RV basal diameter indexed for BSA (2DRVdi), 2D TA measured in the apical 4-chamber view and 2D TA measured in the apical 4-chamber view indexed for BSA. To identify the threshold values of the parameters that discriminate patients with right chamber enlargement associated to severe TR, we selected the probability which returns the best sum of sensitivity and specificity on the ROC curve of the model.

Results

According to EACVI multiparametric approach, 50/302 pts (17%) were found to have severe TR. As shown in Figure, 3DRAi > 45 ml/m2 and 2DRAi > 45 ml/m2 identified patients with RA enlargement associated to severe TR. RVEDVi and RVESVi did not show any predictive value for severe TR. Conversely, 2DRVd > 52 mm (or >30 mm/m2) was associated to severe TR. 2DTA > 42 mm ( or >24 mm/m2) was the selected threshold value for TA dilatation.

Conclusions

Our study provided the threshold values to define the right chamber and TA dilatation associated to severe TR. Implementation of those values in current guidelines can help clinicians to improve their accuracy to identify patients with severe TR.

Abstract 47 Figure.

P764 Right ventricular basal diameter, but not volume, can predict severe tricuspid regurgitation

Background

According to current EACVI guidelines, right ventricle (RV), tricuspid anulus (TA) and right atrium (RA) dilatation are supportive signs to identify severe functional tricuspid regurgitation (TR) by echocardiography. However, the ranking by which those parameters should be considered to identify severe TR remains to be clarified.

Purpose

Accordingly, the aim of this study is to compare RV, RA and TA association with severe TR and to rank them in order of importance to predict severe TR.

Methods

302 patients (59 ± 13 years, 54 % women) with functional TR underwent two- and three-dimensional echocardiography. Using the nonparameteric Variable Importance (VIMP) software package, we assessed the relative importance of 6 differerent parameters (indexed by body surface area) to identify severe TR: 3D RV end diastolic volume (RVEDVi), 3D RV end systolic volume (RVESVi), 3D RA max volume (3DRAi), 2D RA systolic volume (3DRAi), 2D RV basal diameter (2DRVdi) and 2D TAi measured in the apical 4-chamber view.

Results

According to EACVI multiparametric approach, 50/302 pts (17%) were found to have severe TR. 3DRAi (VIMP = 0.075) was the most important predictor of severe TR. 2DRVdi (VIMP= 0.005) was the second most important parameter and was the only parameter of RV dilation (RVEDVi= -0.0011 and RVESVi= -0.0012) associated to severe TR. Also, 2DRAi (VIMP= 0.023), and 2D TAi (VIMP= 0.004) showed good predictive ability.

Conclusions

Among the various right heart structures undergoing remodeling in patients with functional TR, RA dilation was the most important predictor of severe TR. Also the RV basal diameter, but not the volumes, was a predictor of severe TR. This underlines the importance of the shape, more than the volume of the RV as a predictor of severe TR.