Accuracy of Doppler echocardiography in the assessment of pulmonary hypertension in liver transplant candidates

Pulmonary hypertension has been associated with poor outcome after liver tr ansplantation. We assessed the diagnostic accuracy of Doppler echocardiogra phy in detecting significant pulmonary hypertension. Seventy-four potential liver transplant candidates underwent Doppler echocardiography in which th e systolic right ventricular pressure (RVsys) was used to estimate the syst olic pulmonary artery pressure (PAsys). Group 1 included 39 consecutive pat ients with RVsys greater than or equal to 50 mm Hg who underwent elective r ight heart catheterization. Group 2 consisted of 35 patients with RVsys <50 mm Hg in whom pulmonary artery pressures were measured at the beginning of the transplantation procedure. The accuracy of the estimates by Doppler ec hocardiography was assessed against measurements made by direct catheteriza tion. Patients in groups 1 and 2 were comparable in their demographic and l iver disease characteristics. There was a strong correlation between RVsys by Doppler echocardiography and PAsys by right heart catheterization (r =.7 8, P <.01). Of the 39 patients in group 1, 29 (72%) had at least moderate p ulmonary hypertension (mean pulmonary artery pressure [MPAP] greater than o r equal to 35 mm Hg), including 12 (30%) with severe pulmonary hypertension (MPAP greater than or equal to 50 mm Hg). Only 1 of the group 2 patients h ad MPAP greater than or equal to 35 mm Hg. Thus, in the diagnosis of modera te to severe pulmonary hypertension, the sensitivity of echocardiography wa s 97% and specificity was 77%. Doppler echocardiography is an accurate scre ening test to detect moderate to severe pulmonary hypertension. We advise t hat liver transplant candidates with RVsys greater than or equal to 50 mm H g undergo right heart catheterization to fully characterize pulmonary hemod ynamics.