Impact of Predicted Heart Mass−Based Size Matching for Donor-Recipient Selection on Transplant Outcomes

Purpose Currently, guide for appropriate donor sizing in recipients mostly focuses on donor-recipient body weight matching. The purpose is to retrospectively determine the impact of predicted heart mass (pHM)-based size matching among recipients on heart transplantation (HT) outcomes. Methods According to our institutional registry, 512 consecutive adult patients underwent HT between January 2000 and August 2020. For each patient, pHM and donor-recipient pHM ratio have been calculated (4 patients were excluded for missing anthropometric data). Patients were partitioned into quintiles in terms of pHM ratio: Undersizing2 (n=101), Undersizing1 (n=102), Reference (n=102), Oversizing1 (n=102), Oversizing2 (n=101) with a mean pHM donor-recipient ratio of 0.81, 0.96, 1.04, 1.12, 1.28, respectively. Severe early graft failure, 30-day, 90-day and 1-year mortality were analyzed as early outcomes. Results Several characteristics were significantly different between groups. Recipients of the most oversized group were mostly male (p 0.05). Kaplan-Mayer and Cox-regression analysis after adjustment for pHM ratio subgroups did not show any difference in outcomes (p>0.05). Conclusion A wide range of pHM donor-recipient ratios seem to be safe (0.81-1.28). Providing a pHM-based oversized graft to more compromised patients may preserve good outcomes. Instead, low risk profile patients may have acceptable outcomes even in the presence of extremely undersized pHM ratio calculation. A careful allocation of organs, by considering a pHM ratio mismatch, may balance rescue preoperative clinical profiles and preserve HT outcomes.