Multiparametric vs. Inferior Vena Cava-Based Estimation of Right Atrial Pressure

Abstract

Background: Right atrial pressure (RAP) can be estimated by echocardiography from inferior vena cava diameter and collapsibility (eRAP_IVC), tricuspid E/e' ratio ( ${\text{eRAP}}_{\text{E}/{\text{e}}^{\text{'}}}$ ), or hepatic vein flow (eRAP_HV). The mean of these estimates (eRAP_mean) might be more accurate than single assessments. Methods and Results: eRAP_IVC, ${\text{eRAP}}_{\text{E}/{\text{e}}^{\text{'}}}$ , eRAP_HV (categorized in 5, 10, 15, or 20 mmHg), eRAP_mean (continuous values) and invasive RAP (iRAP) were obtained in 43 consecutive patients undergoing right heart catheterization [median age 69 (58-75) years, 49% males]. There was a positive correlation between eRAP_mean and iRAP (Spearman test r = 0.66, P < 0.001), with Bland-Altman test showing the best agreement for values <10 mmHg. There was also a trend for decreased concordance between eRAP_IVC, ${\text{eRAP}}_{\text{E}/{\text{e}}^{\text{'}}}$ , eRAP_HV, and iRAP across the 5- to 20-mmHg categories, and iRAP was significantly different from ${\text{eRAP}}_{\text{E}/{\text{e}}^{\text{'}}}$ and eRAP_HV for the 20-mmHg category (Wilcoxon signed-rank test P = 0.02 and P < 0.001, respectively). The areas under the curve in predicting iRAP were nonsignificantly better for eRAP_mean than for eRAP_IVC at both 5-mmHg [0.64, 95% confidence interval (CI) 0.49-0.80 vs. 0.70, 95% CI 0.53-0.87; Wald test P = 0.41] and 10-mmHg (0.76, 95% CI 0.60-0.92 vs. 0.81, 95% CI 0.67-0.96; P = 0.43) thresholds. Conclusions: Our data suggest that multiparametric eRAP_mean does not provide advantage over eRAP_IVC, despite being more complex and time-consuming.

Keywords: echocardiograghy; heart failure; pulmonary hypertension; right atrial pressure; right heart catheterization.

Figure 1

Echocardiographic right atrial pressure estimation. (A) IVC end-expiratory diameter (blue dotted line) and respiratory variation (solid line). (B) HV pulsed wave Doppler assessment: Vs (red dot), Vd (purple dot), VTIs (red dotted line), and VTId (purple dotted line). (C,D) Tricuspid E/e′ ratio: pulsed wave Doppler tricuspid inflow early E-wave peak velocity (green dot) and tricuspid lateral annulus tissue Doppler imaging e′ wave velocity (green square). IVC, inferior vena cava; HV, hepatic vein; Vs, hepatic vein peak systolic velocity; Vd, hepatic vein peak diastolic velocity; VTIs, velocity-time interval of the HV systolic wave; VTId, velocity-time interval of the HV diastolic wave.

Figure 2

Correlation between multiparametric estimation and invasive measurement of right atrial pressure. (Left) Positive correlation between eRAP_mean and iRAP as assessed by RHC (Spearman correlation test). (Right) Bland–Altman plot showing that estimation of iRAP by eRAP_mean was especially good for values <10 mmHg. The blue lines represent the average ± 1 standard deviation of (eRAP_mean and iRAP). Note that in both analyses some subjects had the same values, hence the relevant dots overlap in the graphs. eRAP_mean, multiparametric estimated RAP; iRAP, invasive RAP; RHC, right heart catheterization.

Figure 3

Correlation between single-parameter estimation and invasive measurement of right atrial pressure. The actual values of iRAP obtained during RHC are presented for each 5-mmHg threshold and by eRAP component. Horizontal bars indicate medians and interquartile ranges, *P < 0.05 and **P < 0.001, respectively (Wilcoxon signed-rank test). iRAP, invasive right atrial pressure; eRAP, estimated right atrial pressure; IVC, inferior vena cava; E/e′ ratio of pulsed wave Doppler tricuspid inflow early E-wave peak velocity and tricuspid lateral annulus tissue Doppler imaging e′ wave velocity; HV, hepatic veins.

Figure 4

ROC curves showing the accuracy of the different modalities of estimation of right atrial pressure in predicting the actual value, as measured during right heart catheterization, for the 5-mmHg (A) and 10-mmHg (B) thresholds. In (A), the AUC of eRAP_IVC and eRAP_HV overlap. eRAP_IVC, estimated right atrial pressure (eRAP) based on inferior vena cava (IVC) diameter and respiratory variation; eRAP_HV, eRAP based on the hepatic vein (HV) pulsed wave Doppler spectra; eRAP_E/e', eRAP based on the tricuspid E/e′ ratio; eRAP_mean, mean of the different eRAP.