Pulmonary hypertension · Estimating pulmonary pressures non-invasively
Accuracy of Doppler echocardiography in the hemodynamic assessment of pulmonary hypertension
| Design | Prospective evaluation study with near-simultaneous right heart catheterisation |
|---|---|
| Treatment | Doppler echocardiographic estimate of pulmonary artery systolic pressure and cardiac output |
| Control | Right heart catheterisation |
| Population | Patients undergoing evaluation for pulmonary hypertension |
| Follow-up | Diagnostic study |
| Primary endpoint | Agreement between Doppler and invasive measurements |
| Result | Bias for pulmonary artery systolic pressure was -0.6 mmHg but the 95% limits of agreement ran from +38.8 to -40.0 mmHg. Doppler was inaccurate by more than 10 mmHg in 48% of cases. Underestimation was larger in magnitude than overestimation (-30±16 versus +19±11 mmHg, p=0.03) and more often led to misclassification of severity. For cardiac output, bias was -0.1 L/min with limits of agreement +2.2 to -2.4 L/min. |
| Secondary endpoints | Cardiac output agreement, direction and magnitude of error |
Doppler echocardiography may frequently be inaccurate in estimating pulmonary artery pressure and cardiac output in patients being evaluated for PH.
The trial authors, in the published abstract
The bias of -0.6 mmHg is the trap: on average echocardiography is right, and on any individual patient it can be 40 mmHg out in either direction. Mean agreement is not the same as agreement. Confirms Arcasoy 2003 in a non-transplant population and underpins the requirement for catheterisation before diagnosing pulmonary arterial hypertension.
Fisher MR, Forfia PR, Chamera E, et al. Accuracy of Doppler echocardiography in the hemodynamic assessment of pulmonary hypertension. Am J Respir Crit Care Med 2009 Apr 1;179(7):615-21.