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

Figure 1. Comparison of PASP between catheterization and conventional echocardiographic estimation. A, Comparison of PASP. B, Correlation of PASP. Compared with RHC, simultaneous echocardiography demonstrated a bias of +1.3 mm Hg for PASP (95% LOA, −12.8 to 15.5 mm Hg). There was a good correlation between the 2 tests (r=0.85, P<0.001). LOA indicates limits of agreement; PASP, pulmonary artery systolic pressure; and RHC, right heart catheterization.

Figure 2. Invasively measured RAP based on conventional echocardiographic criteria. Among the 48 patients, eRAP values were 3 mm Hg in 9 (18.8) patients, 8 mm Hg in 8 (16.7) patients, and 15 mm Hg in 31 (64.6%) patients. The invasively measured RAP for these groups was 3.9±2.0 mm Hg, 8.1±2.2 mm Hg, and 15.0±5.2 mm Hg, respectively. A significant difference was observed between the groups (P<0.001), suggesting a strong correlation between estimated RAP and invasively measured RAP. RAP indicates right atrial pressure.

Figure 3. Invasively measured RAP according to echocardiographic parameters in patients with estimated RAP of 15 mm Hg. A, IVC collapsibility. B, IVC collapsibility 20%. C, Presence of hepatic vein systolic flow reversal. D, Presence of the V‐wave cutoff sign. Invasively measured RAP based on IVC collapsibility, hepatic vein systolic flow reversal, and the V‐wave cutoff sign in 31 patients with an eRAP of 15 mm Hg is shown. IVC collapsibility, hepatic vein systolic flow reversal, and the V‐wave cutoff sign are key determinants of RAP, highlighting their clinical significance in the noninvasive assessment of right atrial pressure. eRAP indicates estimated right atrial pressure; IVC, inferior vena cava; and RAP, right atrial pressure.

Figure 4. Comparison of RAP between catheterization measurements and echocardiographic estimation using new criteria. Using the proposed new echocardiographic criteria, 31 patients with an eRAP of 15 mm Hg were further divided into 3 groups with eRAP values of 10, 15, or 20 mm Hg, resulting in significant differences in invasively measured RAP. eRAP indicates estimated right atrial pressure; PASP, pulmonary artery systolic pressure; and RAP, right atrial pressure.

Figure 5. Comparison of PASP between catheterization and echocardiographic estimation (A) and their correlation (B) using new criteria. By adopting the new eRAP values and recalculated PASPecho_new, the bias between PASPecho_new and PASPcath across all patients was +1.6 mm Hg, with 95% LOA ranging from −9.8 mm Hg to +12.9 mm Hg. There was a strong correlation (r=0.90) between echocardiography and RHC for PASP, representing a significant improvement (P=0.008) compared with the conventional echocardiographic measurements. eRAP indicates estimated right atrial pressure; LOA, limits of agreement; PASP pulmonary artery systolic pressure; and RHC, right heart catheterization.