Objectives: This study was performed to assess whether the combination of multiple echocardiographic and Doppler variables can provide a reliable estimation of pulmonary artery wedge pressure in patients with chronic heart failure.
Background: In patients with chronic heart failure a high pulmonary artery wedge pressure is associated with poor prognosis, more severe symptoms and low exercise tolerance. Several Doppler echocardiographic indexes have been shown to be related to pulmonary artery wedge pressure, but the dispersion of data has generally not allowed a quantitative assessment of this important variable.
Methods: Simultaneous Doppler echocardiographic examinations and right heart catheterizations were performed in 231 patients with chronic heart failure due to dilated cardiomyopathy. Mitral and pulmonary venous flow velocity variables, left atrial volumes, mitral regurgitation jet area and left ventricular ejection fraction were correlated with pulmonary artery wedge pressure by both single and multilinear regression analysis. The reliability of the obtained multilinear equations was then tested in a separate group of 60 patients.
Results: By univariate analysis, the deceleration rate of early diastolic mitral flow and the systolic fraction of pulmonary venous flow showed the strongest correlations (r=0.78 and =-0.76, respectively). Stepwise regression analysis led to two multilinear equations for predicting pulmonary artery wedge pressure in the whole population: the first included only two-dimensional echocardiographic and mitral flow velocity variables (r=0.84) and the second also included pulmonary venous flow variables (r=0.87). The highest correlation was obtained (r=0.89) by a third equation in the 73 patients without significant mitral regurgitation. Correlation coefficients between estimated and measured pulmonary artery wedge pressure were 0.91 (SEE=2.7 mm Hg) and 0.97 (SEE=1.8 mm Hg) when the first and the second equation, respectively, were applied to the testing group.
Conclusions: These results indicate that, in patients with chronic heart failure due to dilated cardiomyopathy, pulmonary artery wedge pressure can be reliably estimated even when mitral regurgitation is present by combining Doppler echocardiographic variables of mitral and pulmonary venous flow.