Discordant Doppler Right Heart Catheterization Pulmonary Artery Systolic Pressures: Importance of Pulmonary Capillary Wedge Pressure

BackgroundAlthough 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. MethodsWe 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. ResultsOf 69 patients, 52 (75.4%) had estimable D-PASP. D-RHC PASP r=0.62 and 51.9% had a PASP difference >10mmHg, 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. ConclusionPulmonary capillary wedge pressure appears to be a significant covariate in the correlation between D and RHC PASP.