Cardiology Letters 2013, 22(6):459-465

Pulmonary artery systolic pressure - direct measurement versus echocardiograhic estimation in patients with pulmonary arterial hypertension and pulmonary venous hypertension

Solík P¹, Lesný P¹, Luknár M¹, Varga I¹, Wimmerová S², Gonçalvesová E¹

¹ Centrum pre pľúcnu artériovú hypertenziu, Oddelenie zlyhávania a transplantácie srdca, Národný ústav srdcových a cievnych chorôb a.s. v Bratislave, Slovenská republika

² Ústav biofyziky, informatiky a bioštatistiky, Fakulta verejného zdravotníctva, Slovenská zdravotnícka univerzita v Bratislave, Slovenská republika

Introduction: Right heart catheterization is the "gold standard" for the diagnosis of pulmonary hypertension (PH). Echocardiography is due to the easy availability, low cost, non-invasivity and fast realization often used as a screening tool for PH, in assessing its causes and prognosis.

Objective: To evaluate the accuracy of the pulmonary artery systolic pressure (sPAP) estimation by Doppler echocardiography compared with direct invasive measurement using right heart catheterization (RHC) and to analyse the causes of discrepancies in these two methods.

Patients and methods: Two hundred seventeen patients (145 men, 72 women). In all of them echocardiography was performed focusing on the detection of PH and all subsequently underwent RHC. Echocardiography was performed within 24 hours before the RHC. Invasive measurement was performed using the Swan-Ganz thermodilution catheter inserted through internal jugular vein into pulmonary artery. (Concordance between echocardiographic estimation and direct measurement of sPAP was defined as the difference between the measurement and the estimated value ≤ 15% of the measured value).

Results: Pulmonary artery systolic pressure values estimated by echocardiography significantly correlated with direct measurement through RHC (correlation coefficient r = 0.747, p < 0.001). The difference between the direct measurement and echocardiographic estimation ranged from -25.6 to +31.1 mmHg (95% CI). Concordance was in 103 cases (47,5%). In 80 cases (36,9%) the echocardiographic estimation of sPAP was higher than the value measured by RHC. On the contrary, in 34 cases (15,6%) sPAP estimated by echocardiography was lower than the value measured by RHC. Degree of tricuspid regurgitation is a factor that affects the accuracy of the echocardiographic assessment of pulmonary artery pressure. For right ventricular function assessed using TAPSE (tricuspid annular plane systolic excursion), we found no significant effect on the accuracy of the echocardiographic estimation of pulmonary artery pressure. Underestimation occurs mainly in patients where an estimated sPAP ≤ 36 mmHg (28,2% underestimated results). Overestimation occurs mainly in cases where the echocardiographic estimation of sPAP > 50 mmHg (40,7% overestimated results).

Conclusion: Despite good correlation between these two modalities in determination of pulmonary artery pressure reliable quantification of PH is possible only through the right heart catheterization. From a clinical point of view it is important to note that nearly 30% of patients in whom pulmonary hypertension was estimated as mild indeed have a higher sPAP. This means that patients with clinical suspicion of pulmonary arterial hypertension and negative echocardiography are indicated for right heart catheterization. Fig. 2, Tab. 5, Ref. 11, Online full text (/Free, PDF)

Keywords: pulmonary hypertension; echokardiography; right heart catheterization

Published: June 1, 2013  Show citation