Three-dimensional Tricuspid Area. A New Criterion to Improve Patient Selection for Annuloplasty in Tricuspid Regurgitation

Abstract Introduction and objectives Late functional tricuspid regurgitation after rheumatic left-sided valve surgery is an important predictor of poor prognosis. This study investigated the usefulness and accuracy of 3-dimensional transthoracic echocardiography tricuspid area compared with conventional 2-dimensional diameter (2DD) for assessing significant tricuspid annulus dilatation, providing cutoff values that could be used in clinical practice to improve patient selection for surgery. Methods We prospectively included 109 patients with rheumatic heart disease in the absence of previous valve replacement. Tricuspid regurgitation was divided into 3 groups: mild, moderate, and severe. Optimal 3-dimensional area (3DA) and 2DD cutoff points for identification of significant tricuspid annulus dilatation were obtained and compared with current guideline thresholds. Predictive factors for 3DA dilatation were also assessed. Results Optimal cutoff points for both absolute and adjusted to body surface area (BSA) tricuspid annulus dilatation were identified (3DA: 10.4 cm 2 , 6.5 cm 2 /m 2 ; 2DD: 35 mm, 21 mm/m 2 ); 3DA/BSA had the best diagnostic performance (AUC = 0.83). Three-dimensional transthoracic echocardiography tricuspid area helped to reclassify surgical indication in 14% of patients with mild tricuspid regurgitation (95%CI, 1%-15%; P  = .03) and 37% with moderate tricuspid regurgitation (95%CI, 22%-37%; P P  = .01) compared with 2DD/BSA. On multivariable analysis, right and left atrial volumes and basal right ventricle diameter were independently correlated with 3DA. Conclusions The current 40 mm threshold underestimates tricuspid annulus dilatation. Although 21 mm/m 2 seems to be a reasonable criterion, the combination with 3DA assessment improves patient selection for surgery.