1Division of Gastroenterology, Department of Medicine, University of Pennsylvania; Clinical Center for Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania. Electronic address: firstname.lastname@example.org.
2Division of Gastroenterology, Department of Medicine, Hershey Medical Center.
3Division of Gastroenterology, Hepatology, and Nutrition, Department of Internal Medicine, The University of Texas Health Science Center at Houston.
4Department of Hepatology, Baylor University Simmons Transplant Institute.
5Clinical Center for Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania; Pulmonary, Allergy, and Critical Care Division, Department of Medicine, University of Pennsylvania.
BACKGROUND AND AIMS:
Patients with hepatopulmonary syndrome (HPS) are prioritized for liver transplantation (given exception points) due to their high pre- and post-transplant mortality. However, few studies have evaluated outcomes of these patients.
We performed a retrospective cohort study using data submitted to United Network for Organ Sharing in a study of the effects of room air oxygenation on pre- and post-transplant outcomes of patients with HPS. We identified thresholds associated with post-transplant survival using cubic spline analysis, and compared overall survival times of patients with and without HPS.
From 2002 through 2012, 973 patients on the liver transplant waitlist received HPS exception points. There was no association between oxygenation and waitlist mortality among patients with HPS exception points. Transplant recipients with more severe hypoxemia had increased risk of death after liver transplant. Rates of 3 y unadjusted post-transplant survival were 84% for patients with PaO2 of 44.1-54.0 mm Hg vs 68% for those with PaO2 ≤44.0 mm Hg. In multivariable Cox models, transplant recipients with an initial room-air PaO2≤44.0 mm Hg had significant increases in post-transplant mortality (hazard ratio, 1.58; 95% confidence interval [CI], 1.15-2.18), compared to those with a PaO2 of 44.1-54.0 mm Hg. Overall mortality was significantly lower among waitlist candidates with HPS exception points than those without (hazard ratio, 0.82; 95% CI, 0.70-0.96), possibly because patients with HPS have a reduced risk of pre-transplant mortality and similar rate of post-transplant survival.
While there was no association between pre-transplant oxygenation and waitlist survival in patients with HPS MELD exception points, a pre-transplant room-air PaO2 ≤44.0 mm Hg was associated with increased post-transplant mortality. HPS MELD exception patients had lower overall mortality compared to others awaiting liver transplantation, suggesting that the appropriateness of the HPS exception policy should be reassessed.