Relationship of main pulmonary artery diameter to pulmonary arterial pressure in scleroderma patients with and without interstitial fibrosis

Abstract

Objective: This study aimed to determine the relationship between main pulmonary artery diameter (MPAD) and pulmonary hypertension (PH) in scleroderma patients with and without interstitial lung disease.

Methods: We retrospectively reviewed 48 subjects with scleroderma who underwent a chest computed tomography (CT) and right heart catheterization with 6 months of each other. Patients were divided into 2 groups based on the absence or presence of interstitial lung disease on chest CT. Subset analysis was performed based on available pulmonary function tests and divided into groups by forced vital capacity (FVC). Computed tomographic scans were scored for extent of fibrosis and ground glass opacity. Pulmonary artery and ascending aorta measurements were obtained by 2 independent observers. Univariate and multivariate models were used to evaluate the correlation between MPAD and mean pulmonary artery pressure (mPAP) measured by right heart catheterization. Receiver operating characteristic analysis was performed for diagnostic accuracy of the MPAD measurement in predicting PH.

Results: Strong correlations between mPAP and MPAD were found in this study regardless of the presence or absence of mild to moderate interstitial fibrosis on chest CT. When dividing patients based on FVC, the correlation between mPAP and MPAD was substantially attenuated. An MPAD value of 30.8 mm yielded the highest sensitivity and specificity at 81.3% and 87.5%, respectively.

Conclusions: In scleroderma patients, an enlarged main pulmonary artery (>30 mm) predicts PH even in the presence of mild to moderate fibrosis although the relationship may be attenuated in the presence of a low % FVC.

Figure 1

Example of measurements made for main pulmonary artery and aortic diameter.

Figure 2

Plots of Log mPAP vs. MPAD for Various Patient Groups

Figure 3

ROC Curve for MPAD Measurement