New Echocardiographic Algorithm for Estimating Right Atrial Pressure in Severe Tricuspid Regurgitation: Insights From Simultaneous Cardiac Catheterization.

Background: The accuracy of echocardiographic estimation of pulmonary artery pressure has been questioned in patients with severe tricuspid regurgitation (TR). This study aimed to evaluate the accuracy of echocardiographic estimates of pulmonary artery pressure compared with simultaneous right heart catheterization (RHC) in patients with severe TR.

Methods: In this prospective observational study, a total of 48 patients with severe TR were enrolled between September 2021 and August 2024 at an experienced RHC center. Data were obtained by simultaneously measuring echocardiography and RHC parameters. The correlation between pulmonary arterial systolic pressure (PASP) measured by echocardiography and RHC was analyzed using Pearson correlation and Bland-Altman analysis.

Results: The median age was 71.5 years, and 26 (54.2%) of the patients were women. Forty-three (89.6%) patients had secondary TR as the underlying pathogenesis. There was a good correlation (r=0.85 as Pearson correlation, P<0.001) between PASP measurements obtained via echocardiography and RHC, with a bias of +1.3 mm Hg and 95% limits of agreement ranging from -12.8 to 15.5 mm Hg. Incorporating parameters such as inferior vena cava collapsibility of ≤20%, hepatic vein systolic flow reversal, and the V-wave cutoff sign further stratified the estimated right atrial pressure to 10, 15, or 20 mm Hg in patients initially estimated to have a right atrial pressure of 15 mm Hg (P<0.001). The use of these new criteria improved the correlation for PASP estimation by echocardiography compared with RHC (r=0.90, P<0.001).

Conclusions: Echocardiography demonstrated good agreement with invasively measured PASP. Incorporating additional echocardiographic parameters significantly enhanced the accuracy of PASP estimation, suggesting a refined noninvasive diagnostic approach in severe TR.