Portopulmonary hypertension: improved detection using CT and echocardiography in combination.

ABSTRACT

OBJECTIVES: To establish the relationship between CT signs of pulmonary hypertension and mean pulmonary artery pressure (mPAP) in patients with liver disease, and to determine the additive value of CT in the detection of portopulmonary hypertension in combination with transthoracic echocardiography. METHODS: Forty-nine patients referred for liver transplantation were retrospectively reviewed. Measured CT signs included the main pulmonary artery/ascending aorta diameter ratio (PA/AAmeas) and the mean left and right main PA diameter (RLPAmeas). Enlargement of the pulmonary artery compared to the ascending aorta was also assessed visually (PA/AAvis). CT measurements were correlated with right-sided heart catheter-derived mPAP. The ability of PA/AAvis combined with echocardiogram-derived right ventricular systolic pressure (RVSP) to detect portopulmonary hypertension was tested with ROC analysis. RESULTS: There were moderate correlations between mPAP and both PA/AAmeas and RLPAmeas (rs = 0.41 and rs = 0.42, respectively; p < 0.005). Compared to transthoracic echocardiography alone (AUC = 0.59, p = 0.23), a diagnostic algorithm incorporating PA/AAvis and transthoracic echocardiography-derived RVSP improved the detection of portopulmonary hypertension (AUC = 0.8, p < 0.0001). CONCLUSIONS: CT contributes to the non-invasive detection of portopulmonary hypertension when used in a diagnostic algorithm with transthoracic echocardiography. CT may have a role in the pre-liver transplantation triage of patients with portopulmonary hypertension for right-sided heart catheterisation. KEY POINTS • CT signs correlate with right-sided heart catheter data in portopulmonary hypertension • CT adds to the transthoracic echocardiography detection of portopulmonary hypertension • CT may have a complementary role in pre-liver transplantation triage.