Adult: Heart Transplantation
Total ventricular mass oversizing +50% or greater was a predictor of worse 1-year survival after heart transplantation

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Abstract

Objectives

Current donor-recipient size matching guidelines rely primarily on body weight, with no specified oversizing cutoff values. Recent literature has explored predicted total ventricular mass matching over body weight matching. We aim to explore the impact of total ventricular mass oversizing on heart transplant outcomes.

Methods

The United Network for Organ Sharing database was queried for adults who underwent primary heart transplant from 1997 to 2017. By using validated equations, donor-recipient total ventricular mass mismatch was calculated. Donor-recipient pairs were divided into 3 groups by total ventricular mass mismatch. Post–heart transplant 1-year survival was analyzed using the Kaplan–Meier method and Cox proportional hazards models. We also investigated post–heart transplant complications, independent predictors for mortality, donor-recipient sex mismatch, and donor-recipient body habitus in total ventricular mass mismatch greater than +50%.

Results

A total of 34,455 donor-recipient pairs were included. Fractional polynomial regression demonstrated increased the risk of mortality with higher total ventricular mass mismatch. Total ventricular mass mismatch of +48.3% maximized the Youden Index. Donor-recipient pairs were subsequently grouped by total ventricular mass mismatch as −20% to +30%, +30% to +50%, and greater than +50%. Total ventricular mass mismatch greater than +50% was an independent risk factor for 1-year mortality (hazard ratio, 1.40, P = .004) and was associated with increased postoperative stroke (P = .002). Some 80.3% of these recipients were smaller female patients with male donors. Total ventricular mass mismatch from +30% to +50% was not associated with worse survival (P = .17).

Conclusions

Total ventricular mass mismatch greater than +50% is associated with worse 1-year survival, although this group comprises a small portion of heart transplant. total ventricular mass mismatch from +30% to +50% is not associated with worse survival. These outcomes should be considered in selecting donors and in efforts to expand the potential donor pool.

Section snippets

Data Source

We used the United Network for Organ Sharing (UNOS) Database as a source of de-identified donor and recipient HTx data. This database consists of prospectively collected donor and recipient demographic and transplant data for all organ transplants performed in the United States. Because the UNOS database is publicly available and deidentified, this study was deemed exempt from Institutional Review Board review.

Inclusion and Exclusion Criteria

We included adult HTx recipients who received transplantation from January 1997 to

Donor-Recipient Matching

Figure 1 shows the distribution of TVM mismatch in all donor-recipient pairs. Median TVM mismatch was 2.8% (interquartile range, −5.8% to +14.8%).

Figure E2 shows the distribution of donor-recipient sex matching in the entire cohort. A total of 21.0% of transplants had sex mismatch. Female donor to male recipient pairings comprised 8.8% (N = 3016) of transplants. Figure E3, A-C, demonstrates the breakdown of gender mismatch in the different TVM mismatch groups. Groups with TVM oversizing had a

Discussion

This retrospective analysis of the UNOS database explored the impact of TVM oversizing on outcomes of HTxs performed over a 20-year period between 1997 and 2017. Our findings suggest that TVM mismatch greater than +50% is associated with a higher risk of 1-year mortality, but donor hearts with TVM mismatch +30% to +50% are not associated with a higher risk of 1-year mortality. The post-HTx mortality seen with TVM mismatch greater than +50% is observed early within the post-HTx period. However,

Conclusions

Assessing TVM before HTx may be useful in predicting outcomes. We analyzed donor TVM and its effect on HTx results using the UNOS registry. TVM mismatch greater than +50% is associated with worse 1-year survival, although comprising a small portion of transplants. TVM mismatch between +30% and +50% did not show worse survival. These donors should be considered for more liberal use with appropriate risk and benefit considerations under clinical experience (Video 1 and Figure 4).

References (23)

Cited by (1)

Because the UNOS database is publicly available and deidentified, this study was deemed exempt from Institutional Review Board review.

1

M.K. and A.C.C. are co-first authors.

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