MAGNETIC-RESONANCE IMAGING-DERIVED PARAMETER OF PORTAL FLOW PREDICTS VOLUME-MEDIATED PULMONARY-HYPERTENSION IN LIVER-TRANSPLANTATION CANDIDATES

Background. Pulmonary hypertension is a source of perioperative mortal ity after orthotopic liver transplantation (OLT). The purpose of this study is to (1) characterize the pulmonary hemodynamic response-in OLT candidates, and (2) determine whether portal flow index (PFI), a magn etic resonance imaging (MRT)-derived parameter, is a useful predictor of the pulmonary hemodynamic response. Methods. Twenty-five consecutiv e OLT candidates underwent right heart catheterization with pressure m easurements at baseline and after infusion of 1 L of crystalloid. MRI, chest roentgenography electrocardiography, and enhocardiography were also performed as routine screening techniques. Sixteen patients in in tensive care unit with normal liver function served as controls. Resul ts. After volume infusion, pulmonary hypertension (mean pulmonary arte ry pressure greater than 25 mm Hg) developed in 9 of 25 OLT candidates with elevations in both pulmonary capillary wedge and mean pulmonary pressures. In contrast, 0 of 16 controls experienced pulmonary hyperte nsion (p < 0.01). Although routine modalities did not predict this hem odynamic response, PFI had a 94% specificity and 78% sensitivity. Conc lusions. OLT candidates exhibit volume-induced pulmonary hypertension with responses suggestive of left ventricular dysfunction. The signifi cance of this observation is unknown, but the MRI-derived parameter, P FI; may serve as a screening technique to limit catheterization to a s elect group of OLT candidates.