Abstract 14732: Refining Donor-Recipient Size Matching Criteria to Optimize Survival after Cardiac Transplantation
Background: While cardiac transplantation remains the best therapy for the treatment of end-stage heart failure, greater application is restricted due to limited donor supply. Improved understanding of size matching may improve short-and long-term outcomes and may render more unused donor hearts usable. Current guidelines recommend that donor weight not be more than 30% below that of the recipient’s weight. We sought to evaluate additional parameters of donor-recipient size matching and their influence on patient survival.
Methods: The UNOS database was used to identify all first time, adult (≥18 years) heart transplant recipients between 1/1/2000 and 6/30/2011. The ratio between recipient-donor weights, heights, and BMIs were explored as potential descriptors of size mismatching. Unadjusted univariate methods (Kaplan-Meier and stratified crosstabulation) were used to identify potential risk factors that directly or through interaction with size-mismatching predict mortality. A multivariate Cox Regression analysis with backward elimination was conducted to assess the effect of size mismatch and the interaction term of size ratio with other risk factors identified in the univariate analysis that were independently predictive of 3-year survival.
Results: This analysis included 18,579 recipients. Size mismatch was defined as donor to recipient ratios greater than 1.5 SD from the mean. There were 241 undersized donors for weight, 868 for height, and 382 for BMI. 1,364 donors were defined as mismatched and oversized for weight, 1,262 for height, and 1,350 for BMI. Larger donors, best defined by donor-recipient BMI ratio, were protective of survival (HR=.68, p=.0002). The interaction between height and gender was a predictor of mortality in taller, female donors with female recipients (HR 2.37, p<.0001).
Conclusions: In this database, the recipients of heart transplants are generally well matched to their donors in all size parameters. Incorporating both height and weight, in terms of BMI, appears to be more influential on recipient survival than each parameter separately. Female recipients receiving a heart from a taller female donor are at increased risk of mortality. The reason for this observation remains elusive.
- © 2012 by American Heart Association, Inc.