The impact of oversized donor matching on clinical outcomes after heart transplantation

Background: Adequate cardiac allograft sizing is one of the main considerations in heart transplantation.Although several studies report the use of undersized hearts and its impact on post-heart transplant outcomes, compelling evidence regarding the use of oversized hearts is lacking.Methods: We identified patients who underwent orthotopic heart transplantation at our institution from November 1992 to September 2020.Patients were categorized based on donor-recipient predicted heart mass (PHM) matched or oversized matched (>30%).The effect of the use of an oversized heart on clinical outcomes was investigated.Results: Of a total of 485 patients, 108 (22.3%) patients received an oversized heart.During follow-up (median, 78.8; postoperative months interquartile range, 39.7-119.4months), death occurred in 116 patients (3.57/patient-year).In multivariable analysis, diabetes mellitus (hazard ratio [HR], 2.25; 95% confidence interval [CI], 1.47-3.44;P<0.001), dialysis (HR, 2.04; 95% CI, 1.05-3.99;P=0.04), preoperative mechanical cardiac support (HR, 2.14; 95% CI, 1.35-3.38;P=0.001) were independent predictors of death.After adjustment for such predictors, spline curves showed that PHM oversized donor was not associated with death (Fig. 1).As size-matched recipients, recipients of oversized hearts showed similar mortality (5 years; 82.8% vs. 82.3%,P=0.6).Conclusions: Utilizing predictive heart mass oversized donors may not be associated with a detriment in survival.