A Comprehensive Risk Score to Predict Prolonged Hospital Length of Stay After Heart Transplantation

Background Prolonged hospital length of stay (PLOS) after heart transplantation increases cost and morbidity. To better inform care, we developed a risk score to identify patients at risk for PLOS after heart transplantation. Methods We queried the United Network for Organ Sharing Scientific Registry of Transplant Recipients database for adult patients who underwent isolated heart transplantation from 2003 to 2012. The population was randomly divided into a derivation cohort (80%) and a validation cohort (20%). The outcome of interest was PLOS, defined as a posttransplant hospital length of stay of more than 30 days. Associated univariables (p < 0.20) in the derivation cohort were included in a multivariable model, and a risk index was derived from the adjusted odds ratios of significant covariates. Results During the study period, 16,723 patients underwent heart transplantation with an average PLOS of 19 ± 21 days, and 2,020 orthotopic heart transplant recipients (12%) had PLOS. Baseline characteristics were similar between the derivation and validation cohorts. Twenty-four recipient and nine donor variables, cold ischemic time, and center volume were tested as univariables. Seventeen covariates significantly affected PLOS and comprised the prolonged hospitalization after heart transplant risk score, which was stratified into three risk groups. The risk model was subsequently validated, and predicted rates of PLOS correlated well with observed rates (R = 0.79). Rates of PLOS in the validation cohort were 8.3%, 11%, and 22% for low, moderate, and high risk groups, respectively. Conclusions The risk of PLOS after heart transplantation can be determined at the time of transplant. The prolonged hospitalization after heart transplant score may lead to individualized postoperative management strategies to reduce duration of hospitalization for patients at high risk.