Heart Transplants From Active COVID Donors Linked With Higher Mortality

Adult heart transplant recipients from donors with active COVID-19 infection had higher mortality at 6 months and at 1 year than those with transplants from donors who had either a recently resolved COVID case or did not have COVID, a retrospective analysis found.

For heart transplant recipients in propensity-matched cohort analyses, post-transplant mortality at 6 months was 4.9% for recipients with non-COVID hearts compared to 13.8% for recipients with active COVID heart transplants. Mortality at 1 year was 9.2% for recipients with non-COVID heart transplants, compared with 23.2% for recipients with active COVID heart transplants, reported Shivank Madan, MD, MHA, of the Montefiore Medical Center and Albert Einstein College of Medicine in the Bronx, New York, and co-authors in the Journal of the American College of Cardiology.

However, heart transplants from recently resolved COVID donors had similar post-transplant mortality to non-COVID donors, with 8.7% and 8.5% mortality at 6 months, respectively, and 13.7% vs 12.6% mortality at 1 year, respectively.

"I think we need to realize that COVID-19 infection can have a wide spectrum of disease severity including extra-pulmonary manifestations in potential donors, and our understanding of the virus in the presence of immunosuppression continues to evolve," Madan told MedPage Today in an email. "I think our study highlights that there is a need for continued evaluation, risk-stratification, and a more nuanced approach in evaluating potential heart donors with COVID-19 infection."

Compared with heart transplant recipients from non-COVID donors, unadjusted analyses showed those who received a transplant from an active COVID donor had increased mortality at 6 months (HR 1.74, 95% CI 1.02-2.96, P=0.043), and at 1 year (HR 1.98 95% CI 1.22-3.22, P=0.006). Adjusted analyses showed similar trends.

"HT [heart transplant] centers have had to continuously modify recipient and donor management practices during the pandemic as our understanding of the COVID-19 virus has evolved," Madan and colleagues wrote. "Our early analysis suggests that while HTs from recently resolved COVID donors appears to be safe, HTs from active COVID donors may be associated with increased mortality."

From May 2020 to June 2022, the authors found the use of COVID heart donors -- both active and recently resolved COVID -- increased significantly and was highest when Delta and Omicron were dominant.

COVID heart donors were younger (30 vs 32 years old), mostly male (80% vs 72%), and were more likely to have died from head trauma (44.77 vs 39%) compared with non-COVID donors.

Autopsy studies have suggested that while viable transmissible virus was limited to the respiratory tract, COVID-19 proteins could still be found outside it, according to Madan and co-authors. A small number of studies have sought to evaluate potential risks of transplantation from donors with a history of COVID-19 infection, and though early outcomes suggested "acceptable short-term outcomes," short follow-up times, the authors noted for one study, were "too short to detect any significant difference."

"This issue directly affects our patients with advanced heart failure on the transplant waiting list; and given the ongoing shortage of organ donors, we as healthcare providers are forced to make a clinical judgement of whether to use potential donors with COVID-19 infection for a heart transplant or not on a routine basis," Madan told MedPage Today. "This becomes especially challenging due to lack of clear outcomes data."

According to Josef Stehlik, MD, MPH, of the University of Utah School of Medicine, who was not involved with the analysis, this "well done study" provided "important insights."

"Importantly, outcome of patients transplanted using donors with recently recovered COVID-19 infection was similar to donors without COVID infection," Stehlik told MedPage Today in an email. "This suggests, that at least in the short term, there is no signal for increased risk and this is quite reassuring."

Stehlik also said the higher risk of mortality in recipients of organs from donors with active infections "is of concern, and we need more data to determine the reason."

"Transmission of COVID from the donor to the recipient has not been reported in heart transplantation, so if there is an increased risk, it is likely through a different mechanism," he added.

Researchers used United Network for Organ Sharing (UNOS) data from May 2020 to June 2022 to identify COVID donors and subdivided this group into active COVID (who had a positive test within 2 days of organ procurement) and recently resolved COVID.

After excluding multiorgan transplants, retransplants, pediatric recipients, and patients with missing follow-up, heart transplants from 150 active COVID and 89 recently resolved COVID donors were included in the study, along with 5,641 heart transplants from non-COVID donors.

For propensity-matched analyses, heart transplants from 150 active COVID donors were matched with 300 non-COVID donors. Heart transplants from 87 recently resolved COVID donors were matched with 174 non-COVID donors.

Recipient mortality was compared using Cox proportional hazards regression models and Kaplan-Meier analysis. All recipients were censored at 1 year of post-transplant follow-up.

Overall median follow-up time for the outcomes analysis cohort was 11.2 months, but only 5.7 months for COVID donor heart transplants. "Despite adjusting, there remains a possibility that the results are confounded by factors not taken into account in the analysis, or due to the fact that not all patients in the study group completed 6- and 12-month follow-up after transplant," Stehlik noted.

Limitations included a wide range of timing and frequency for COVID-19 testing among potential donors despite recommendations to test as close as possible to the time of organ procurement, and a lack of detailed information about COVID disease activity or specific SARS-CoV-2 strain. Vaccination status of donors and recipients was unknown.

The study was not powered sufficiently to directly compare active COVID and recently resolved COVID subgroups, Madan and colleagues said. The researchers also did not have information on anti-retroviral therapies which may have been administered around the time of heart transplants.

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