Paradoxical Outcome of Heart Transplantation Associated with Institutional Case Volume.

Abstract

BACKGROUND\nPrevious studies in heart transplantation have shown an association between institutional case volume and outcomes. We aim to determine the case volume that is associated optimal one-year survival after transplantation.\n\n\nMETHODS AND RESULTS\nThe United Network for Organ Sharing (UNOS) national database was analyzed for adult patients who underwent orthotopic heart transplantation between January 2013 and December 2017. A total of 11,196 cases at 128 transplant centers were included. Risk-adjusted restricted cubic splines revealed a non-linear association between institutional case volume and 1-year post-transplant survival. In the risk-adjusted, random-effect Cox model with segmented linear splines, higher heart transplant volume up to 24 cases per year was associated with better 1-year survival (HR = 0.978 every additional case, 95% CI 0.963 - 0.993), and optimal survival was maintained between 24-38 cases per year. However, further increase in volume above 38 transplants per year was associated with mildly decreased 1-year survival (HR = 1.007 every additional case, 95% CI 1.002-1.013).\n\n\nCONCLUSIONS\nThe relationship between institutional case volume and heart transplant one-year survival is non-linear, with optimal survival observed at institutional case volume of 24 to 38 cases per year. This article is protected by copyright. All rights reserved.