Diagnostic accuracy of echocardiography combined with chest CT in pulmonary hypertension

Abstract

Background: Transthoracic echocardiography (TTE) and computerized axial tomography (CT) are complementary imaging techniques. It is possible that a combination of the two may offer a better way of identifying pulmonary hypertension (PH) than either one alone.

Objectives: To determine the diagnostic accuracy of TTE combined with chest CT in pulmonary hypertension.

Methods: We performed a retrospective review of consecutive patients who had undergone TTE, CT and right heart catheterization (RHC) between 7/1/2008 and 6/30/2012. PH was defined as systolic pulmonary artery pressure >40 mm Hg or tricuspid regurgitant (TR) jet velocity >2.8m/s on TTE, ratio of diameter of pulmonary artery to ascending aorta (rPA) >1 or diameter of PA (dPA) >30 mm on CT, and mean PAP (mPAP) >25 mm Hg on RHC.

Results: There was a total of 87 patients. The mean ± SD age was 54.3 ± 15.9 years and 69 (79%) were female. The prevalence of PH was 75%. The mean ± SD mPAP was 35.8 ± 14.2 mm Hg. The majority of the patients belonged to World Health Organization group I PH. Fifty per cent of the CT scans were done with intravenous contrast dye. The combination of TR jet velocity and rPA provided the best combination of sensitivity (98%) and specificity (70%) with an ROC area under the curve of 0.84.

Conclusion: The combination of TTE and chest CT is better than either imaging technique alone in identifying patients with PH in a heterogeneous population and may exclude PH.

Keywords: chest CT; diagnosis; echocardiography; pulmonary hypertension.