Blood type O heart transplant candidates have longer waitlist time and higher delisting under the new allocation system

Donation after circulatory death improves probability of heart transplantation in waitlisted candidates and results in post-transplant outcomes similar to those achieved with brain-dead donors

OBJECTIVE

To quantitate the impact of heart donation after circulatory death (DCD) donor utilization on both waitlist and post-transplant outcomes in the United States.

METHODS

The United Network for Organ Sharing database was queried to identify all adult waitlisted and transplanted candidates between October 18, 2018, and December 31, 2022. Waitlisted candidates were stratified according to whether they had been approved for donation after brain death (DBD) offers only or also approved for DCD offers. The cumulative incidence of transplantation was compared between the 2 cohorts. In a post-transplant analysis, 1-year post-transplant survival was compared between unmatched and propensity-score-matched cohorts of DBD and DCD recipients.

RESULTS

A total of 14,803 candidates were waitlisted, including 12,287 approved for DBD donors only and 2516 approved for DCD donors. Overall, DCD approval was associated with an increased sub-hazard ratio (HR) for transplantation and a lower sub-HR for delisting owing to death/deterioration after risk adjustment. In a subgroup analysis, candidates with blood type B and status 4 designation received the greatest benefit from DCD approval. A total of 12,238 recipients underwent transplantation, 11,636 with DBD hearts and 602 with DCD hearts. Median waitlist times were significantly shorter for status 3 and status 4 recipients receiving DCD hearts. One-year post-transplant survival was comparable between unmatched and propensity score-matched cohorts of DBD and DCD recipients.

CONCLUSIONS

The use of DCD hearts confers a higher probability of transplantation and a lower incidence of death/deterioration while on the waitlist, particularly among certain subpopulations such as status 4 candidates. Importantly, the use of DCD donors results in similar post-transplant survival as DBD donors.

Utilization of hepatitis C virus infected donors in heart transplant recipients with elevated MELD-XI score

BACKGROUND

The advent of direct-acting antivirals has helped to increase the safe utilization of organs from hepatitis C virus positive (HCV+) donors. However, the outcomes of heart transplantation (HT) using an HCV+ donor are unclear in recipients with underlying liver disease represented by an elevated model for end-stage liver disease excluding international normalized ratio (MELD-XI).

METHODS

The United Network of Organ Sharing database was queried from Jan 2016 to Dec 2021. Post-transplant outcomes stratified by recipient MELD-XI score (low <10.37, medium, 10.38-13.39, and high >13.4) was compared between patients with HT from HCV+ (N = 792) and patients with HT from HCV-negative donors (N = 15,266).

RESULTS

The median MELD-XI score was comparable (HCV+, 12.1, vs. HCV-negative, 11.8, p = .37). In the HCV+ group, donors were older (33 vs. 31 years, p < .001). Ischemic time of donor hearts (3.48 vs. 3.28 h, p < .001) and travel distance (250 vs. 157 miles, p < .001) were longer in HCV+ group. In the Kaplan Meier analysis with a median follow-up of 750 days, survival was comparable between the two groups (2-year survival, MELD-XI Low: HCV+, 92.4 ± 3.6% vs. HCV-negative, 91.1 ±.8%, p = .83, Medium: HCV+ 89.2 ± 4.3% vs. HCV-negative, 88.2 ± 1.0%, p = .68, and High: HCV+, 84.9 ± 4.5% vs. HCV-negative, 84.6 ± 1.1%, p = .75) In multivariate Cox hazard models, HCV donors were not associated with mortality in each MELD-XI subgroup (Low: adjusted hazard ratio (aHR), 1.02, p = .94; Medium: aHR, .95, p = .81; and High: aHR, .93, p = .68).

CONCLUSION

Utilization of HCV+ hearts was not associated with an increased risk of adverse outcomes in recipients with an elevated MELD- XI score.

Use of Donor Hearts ≥50 Years Old for Septuagenarians in Heart Transplantation

BACKGROUND

The impact of using donors ≥50 years old on heart transplantation outcomes of septuagenarians is unknown, which may have a potential to expand the donor pool.

METHODS

From January 2011 to December 2021, 817 septuagenarians received donor hearts <50 years old (DON<50) and 172 septuagenarians received donor hearts ≥50 years old (DON≥50) in the United Network for Organ Sharing database. Propensity score matching was performed using recipient characteristics (167 pairs). The Kaplan-Meier method and Cox proportional hazards model were used to analyze death and graft failure.

RESULTS

The number of heart transplants in septuagenarians has been increasing (54 per year in 2011 to 137 per year in 2021). In a matched cohort, the donor age was 30 years in DON<50 and 54 years in DON≥50. In DON≥50, cerebrovascular disease was the main cause of death (43%), whereas head trauma (38%) and anoxia (37%) were the causes in DON<50 (P < .001). The median heart ischemia time was comparable (DON<50, 3.3 hours; DON≥50, 3.2 hours; P = .54). In matched patients, 1- and 5-year survival rates were 88.0% (DON<50) vs 87.2% (DON≥50) and 79.2% (DON<50) vs 72.3% (DON≥50), respectively (log-rank, P = .41). In the multivariable Cox proportional hazards models, donors ≥50 years old were not associated with death in matched (hazard ratio, 1.05; 95% CI, 0.67-1.65; P = .83) and nonmatched groups (hazard ratio, 1.11; 95% CI, 0.82-1.50; P = .49).

CONCLUSIONS

The use of donor hearts older than 50 years can be an effective option for septuagenarians, thereby potentially increasing organ availability without compromising outcomes.