Impact of “increased-risk” donor hearts on transplant outcomes: A propensity-matched analysis

Abstract

ObjectivesOrthotopic heart transplantation (OHT) remains the gold standard for advanced heart failure. Increased risk (IR) donors were categorized by the United Network for Organ Sharing Database (UNOS) according to the Centers for Disease Control and Prevention (CDC) criteria. However, the impact of CDC IR donor hearts on the outcome of adult OHT recipients remains unclear. The aim of this study was to compare the outcome of adult OHT recipients between CDC IR and non-CDC IR donor grafts. MethodsData were obtained from the United Network for Organ Sharing Databas. All adult patients (age ≥18 years) undergoing OHT from 2004 through 2016 were included (n = 24,751). Propensity scores for CDC IR donors were calculated by estimating probabilities of CDC IR donor graft use using a nonparsimonious multivariable logistic regression model. Patients were matched 1:1 using a greedy matching algorithm based on the propensity score of each patient. The impact of CDC IR donors on the post-transplant outcomes, such as 30-day and overall mortalities, was investigated using Cox-proportional hazards. Overall survival probability analyses were performed. ResultsOf 24,751 primary heart transplants from 2004 to 2016 with 3584 (14.5%) as IR donors, 6304 transplants were successfully matched (n = 3152 in CDC IR group and non-IR group). There were no significant differences in baseline characteristics in recipients and donors. In the Cox-proportional hazards model for matched subjects, the use of CDC IR grafts was not associated with 30-day (hazard ratio of IR group vs non-IR group 0.97; 95% confidence interval, 0.87-1.08; P = .57) and overall mortalities (hazard ratio, 0.94; 95% confidence interval, 0.73-1.21; P = .62). Interestingly, post-transplant acute myocardial rejection episodes during hospital stays were found more often in the CDC-IR group, compared with the non-CDC IR group (CDC IR, n = 358 [11.4%]; non-CDC IR, n = 304 [9.6%] P = .03), whereas post-transplant pacemaker placements were performed less frequently in the CDC IR group (CDC IR, n = 80 [2.6%]; non-CDC IR, n = 111 [3.5%] P = .020). Importantly, there was no significant difference in the overall survival probability between CDC IR and non-IR groups in both unadjusted and adjusted survival analyses. ConclusionsCDC IR status does not have a significant impact on adult OHT recipient survival probability. Increased use of CDC IR donor grafts can potentially alleviate the persistent and worsening shortage of available donor organs and shorten the waitlist time for heart transplantation.