Echocardiographic parameters recommended for assessing the severity of tricuspid regurgitation: concordance and discordance

Background: Current guidelines recommend integrating several echocardiographic indices to evaluate the severity of tricuspid regurgitation (TR). Discordance of indices, including qualitative and quantitative methods, commonly exists in practice. The discordance among these parameters has not yet been fully elucidated. Methods: A total of 127 patients with recognizable TR jets without pulmonary regurgitation or intracardiac shunt were prospectively enrolled. We evaluated 8 parameters by 2-dimensional (2D) echocardiography: proximal iso-velocity surface area (PISA)-derived regurgitant volume (RVol), PISA-derived effective regurgitant orifice area (EROA), PISA radius, vena contracta width (VCW), color Doppler jet area, tricuspid valve annular diameter, inferior vena cava (IVC) diameter, and peak E wave. According to current guidelines, each echocardiographic parameter was determined to represent either severe or non-severe TR. A concordance score was calculated as the number of concordant parameters divided by 8, with a higher score reflecting better concordance. Data were further categorized into 3 subgroups: complete concordance (0 discordant parameters), high concordance (1-2 discordant parameters), and low concordance (3-4 discordant parameters). Results: The mean concordance score was 81%±17% for the entire cohort. There were 48 (38%) patients with complete concordance, including 6 patients with severe TR. In contrast, the low concordance group (n=43, 34%) mostly comprised severe TR patients (36 patients). When considering only EROA, RVol, and VCW, concordance improved, with 98 patients (77%) in complete agreement. Conclusions: Concordance seems limited when using echocardiographic parameters to assess TR severity. Applying only EROA, RVol, and VCW results in better concordance, as recommended by the current guidelines.