Discordant Doppler right heart catheterization pulmonary artery systolic pressures: importance of pulmonary capillary wedge pressure.

Background: Although the echo Doppler (D) estimation of pulmonary artery systolic pressure (PASP) was initially highly correlated with right heart catheterization (RHC), recent D-RHC studies have questioned its accuracy. The aim of this study was to reevaluate this relationship and to determine possible explanations for disparate D-RHC results.

Methods: We retrospectively identified all patients at one institution who underwent RHC and had an echocardiogram within the prior month. Echocardiographic and catheterization hemodynamic factors were evaluated by regression and Bland-Altman analysis.

Results: Of 69 patients, 52 (75.4%) had estimable D-PASP. D-RHC PASP r = 0.62 and 51.9% had a PASP difference >10 mmHg, comparable to other recent studies. The D-RHC difference correlated with pulmonary capillary wedge pressure (PCWP) (r = -0.60, P < 0.001) and right atrial pressure (r = -0.43, P = 0.002). Multivariate analysis including wedge pressure improved the relation between D and RHC for PASP (r = 0.86). These results were little changed using only the respective RV-RA pressure gradients from D and RHC.

Conclusion: Pulmonary capillary wedge pressure appears to be a significant covariate in the correlation between D and RHC PASP.