Determining optimal donor heart ischemic times in adult cardiac transplantation

Abstract

Objectives: Unsupervised statistical determination of optimal allograft ischemic time (IT) on heart transplant outcomes among ABO donor heart types. Methods: We identified 36,145 heart transplants (2000–2018) from the United Network for Organ Sharing database. Continuous and categorical variables were analyzed with parametric and nonparametric testing. Determination of IT cutoffs for survival analysis was performed using Contal and O'Quigley univariable method and Vito Muggeo multivariable segmented modeling. Results: Univariable and multivariable IT threshold determination revealed a cutoff at about 3 h. The hourly increase in survival risk with ≥3 h IT is asymmetrically experienced at the early 90 days (hazard ratio [HR] = 1.29, p 1 year (HR = 1.05, p =.041). For non-O blood types with ≥3 h IT hourly mortality risk was increased at 90 days (HR = 1.33, p