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.