Conference: 2006 International PHA Conference and Scientific Sessions
Release Date: 06.23.2006
Presentation Type: Abstracts
Krowka MJ, Swanson KL, Frantz RP, McGoon MD.
Mayo Clinic College ofMedicine, Rochester, Minnesota, USA.
BACKGROUND: Portopulmonary hypertension (POPH), one substrate for pulmonary hypertension (PH) associated with portal hypertension, is characterized by increased resistance to pulmonary arterial flow due to endothelial/smooth muscle proliferation, vasoconstriction, in-situ thrombosis, and plexogenic arteriopathy. Increased mortality has occurred when orthotopic liver transplantation (OLT) is attempted in such patients, thus screening for POPH is advised.
METHODS: A pulmonary hemodynamic assessment algorithm was followed from 1996 to 2005 in consecutive OLT candidates; 958/1,235 (77.6%) had measurable Doppler echocardiography-derived right ventricular systolic pressure (RVSP). RVSP > 50 mmHg (n = 101) underwent right heart catheterization (RHC) to determine mean pulmonary artery pressure (MPAP), cardiac output (CO), pulmonary artery occlusion pressure (PAOP) and pulmonary vascular resistance (PVR).
RESULTS: Elevated MPAP (> 25 mm Hg; mean 43 ± 14 mm Hg; range 15-86) was documented in 90/101 (90%). Increased PVR (≥ 240 dynes s.cm-5; mean 533 ± 247 dynes.s.cm-5) was found in 66/101 (66%). Of the 35/101 (35%) with normal PVR, increased MPAP (mean 31 ± 9 mm Hg) was primarily due to increased CO (mean 9.1 ± 3.0 l/min) and/or PAOP (21 ± 4 mm Hg). Severity of liver disease was not related to MPAP or PVR. Following screening, no patient was subsequently diagnosed with clinically significant POPH (MPAP > 35 mmHg with increased pulmonary vascular resistance) at the time of OLT; hemodynamic parameters (MPAP and PVR) did not change significantly prior to OLT in those who did not undergo pulmonary vasodilator therapy.
CONCLUSION: Doppler echocardiography (RVSP > 50 mm Hg) with subsequent RHC was necessary to confirm POPH and distinguish subgroups of PH (high flow, elevated central volume, and obstruction to pulmonary arterial flow) in OLT candidates. This algorithm identified all patients with moderate to severe POPH prior to OLT.