Correlation of Echocardiographic and Right Heart Catheterization Estimations of Pulmonary Artery Systolic Pressure

Abstract

Background: Pulmonary artery pressure (PAP) is one of the most important and valuable markers in cardiovascular disease, measured by right heart catheterization (RHC) as the gold standard diagnostic modality. However, due to several limitations, such as invasiveness, lack of repeatability, and high health costs, echocardiographic estimation of PAP has been used to substitute RHC for diagnosis and monitoring of this disease. This study aimed to evaluate the correlation of echocardiographic and RHC estimations of systolic PAP.

Materials and methods: In this study, patients, who were referred to Masih Daneshvari Hospital in Tehran, Iran, evaluated by RHC and echocardiography, were selected. The median PAP (mPAP) and systolic PAP (sPAP) for each modality, time interval between the two modalities, sex, and age were extracted from the patients' records. The RHC mPAP data was used for categorization of patients as pulmonary hypertension, while the sPAP data of two modalities was used to assess correlations and define a cut-off point by the ROC analysis. Data analysis was performed using SPSS version 24, and the level of statistical significance was less than 0.05.

Results: Seventy-six patients, including 31 males (40.8%) and 45 females (59.2%) with the mean age of 45±14 years, were evaluated in this study. The mean sPAP was 71.98±30.22 mmHg when measured by RHC and 69.75±26.03 mmHg when measured by echocardiography (correlation coefficient=0.805; P<0.001). Agreement between the two measurements was 97%, and the accuracy of echocardiography was 43%. By considering 40 mmHg as the cutoff point, the sensitivity and specificity of echocardiography were estimated at 89.2% and 42.8%, respectively. Based on the ROC analysis, the highest sensitivity (86.7%) and specificity (87.5%) were achieved with an estimated sPAP of 57.5 mmHg.

Conclusion: Echocardiography showed a good correlation and agreement with RHC in estimating sPAP; therefore, it is appropriate for screening of patients because of high sensitivity. However, for diagnosis confirmation, monitoring, and follow-up of pulmonary hypertension via echocardiography, high specificity is needed, which can be achieved by considering sPAP of 57.5 mmHg as the cutoff value for pulmonary hypertension.

Keywords: Echocardiography; Pulmonary artery pressure; Pulmonary hypertension; Right heart catheterization; Screening.

Figure 1.

Linear correlation (A) and agreement (Bland-Altman representation) (B) between Doppler echocardiographic and RHC methods for systolic PAP evaluation.

Figure 2.

ROC analysis of all patients and subgroups of them