Echocardiographic Estimation of Mean Pulmonary Artery Pressure: A Comparison of Different Approaches to Assign the Likelihood of Pulmonary Hypertension

Background: Current guidelines advise using echocardiography for noninvasive estimation of the likelihood that a patient has pulmonary hypertension (PH). To estimate the echocardiographic probability of PH, the maximal tricuspid regurgitation velocity (TR Vmax) is recommended as the main parameter to use over more complex algorithms that provide an estimation of pulmonary artery pressure. This preference is based on concerns about inaccuracies and amplification of measurement errors that can occur from using derived variables. However, this has not been examined systematically. Methods: A retrospective database analysis was performed of invasively determined measurements of right heart pressure in 90 patients, corresponding echocardiographic estimations of pulmonary artery pressure, and additional parameters obtained within 24 hours. Several algorithms were compared for their correlations and accuracy parameters. Results: Although a Bland-Altman analysis demonstrated that all examined algorithms exhibited inaccuracies that could be clinically relevant in individuals, algorithms estimating mean pulmonary artery pressure (PAPm) on the basis of tricuspid regurgitation generally exhibited stronger correlations with invasively determined PAPm and more accurate identification of PH than did TR Vmax. Echocardiographic estimation of right atrial pressure > 15 mm Hg exhibited the highest odds ratio for invasively confirmed PH, suggesting that this parameter is of additional diagnostic value. Indeed, algorithms that also considered right atrial pressure performed best, whereas empirical algorithms, TR Vmax, and methods relying on pulmonary acceleration time exhibited weaker performance. Conclusions: Although all methods are associated with inaccuracies, echocardiographically determined PAPm was superior to the current guideline recommendation of using TR Vmax with regard to its correlation with invasively determined PAPm and the presence of PH. PAPm may be considered as an alternative to TR Vmax for evaluating the echocardiographic probability of PH.