In the US in 2019, 3,552 heart transplants were performed, the highest number to date. Unfortunately, waitlists for the life-saving surgery are long – around 20 percent of patients die, or become too sick to go ahead with the transplant, while they wait – meaning that the need to increase the availability of donor hearts is great. Therefore, with the tragic rise in drug overdose deaths in the US, largely facilitated by the opioid crisis, comes a macabre opportunity.
Two studies, published today in two of the American Heart Association's scientific journals, suggest that post-transplant survival rates are unaffected, regardless of whether or not the donor had used illicit drugs or died from an overdose.
According to Howard Eisen, M.D., chair of the American Heart Association's Heart Failure and Transplantation Committee of the Clinical Cardiology Council, who was not involved in either study, the transplanting of hearts from people who have used illicit drugs has been common since 2019. However, it seems some still need a nudge to adopt the practice. "This research confirms previous data that these hearts – once considered high risk – are safe," Eisen said. "These findings should encourage institutions who are not routinely using hearts from drug users to do so. It will reduce the waiting time and the number of deaths among people on the heart transplant waitlist."
The first study, published in Circulation: Heart Failure, is the largest study to date examining drug use of heart transplant donors. It is also the only study to analyze toxicology data at the time of donation. Using nationwide information from the United Network for Organ Sharing (UNOS) database, the team, led by David A. Baran, M.D., compared the survival of 23,748 adult heart transplant patients between 2007 and 2017. The researchers were able to access records of urine tests taken before the donors' death, and could therefore identify the type and number of illicit and none illicit drugs that had been used. These included opioids, cocaine, methamphetamine, alcohol, cannabis, barbiturates, amphetamines, and phencyclidine (PCP). Over the course of the decade, the number and percentage of donors with drug use increased significantly, while, interestingly, alcohol use appeared to decline.
Crucially, the comparison revealed no differences in post-transplant mortality when donors had used illicit drugs and when they hadn’t: about 90 percent of transplant patients survived after one year, irrespective of whether their donor had used opioids or not; about 77 percent survived five years, and roughly 60 percent survived 10 years. Findings were also comparable for other types of drugs, even when the donor tested positive for combinations of multiple drugs.
"We thought that illicit drugs like cocaine or methamphetamine, which can lead to heart attacks, would prove to be dangerous," Baran said. "However, we were wrong. We should not reject a heart from a donor just because they used one or more illicit drugs."
The second study, published in the Journal of the American Heart Association, agrees that a greater acceptance of hearts from donors who have overdosed could increase the number and percentage of heart transplants without jeopardizing survival. They also look at donors with hepatitis C and conclude that the same is true.
"We hope that patients who are awaiting transplants are encouraged to accept hearts from donors who had hepatitis C or who died due to a drug overdose, if their health care team finds the donor heart to be an appropriate match," said lead study author Ravi Dhingra, M.D., M.P.H..
Dhingra and colleagues compared data from 2003–2007 to 2013–2017 and found that, in the latter bracket, donors were typically older, weighed more, and were more likely to have high blood pressure, diabetes, or used illicit drugs – this increases the risk of hepatitis C, which spreads through contact with contaminated blood. However, the risk of death among transplant patients was 15 percent lower one month after surgery and 21 percent lower one year later. It should be noted that explicit consent must be obtained from the patient before acceptance of hepatitis C-donor organs, as well as authorization from a health insurance provider to cover the cost of medications, if necessary.
Together, the results of the studies confirm that hearts from donors who used illicit drugs or died from an overdose are safe for transplantation – a finding that could slash wait times and will, no doubt, be very welcome news for the 3,575 people in the US currently on the list awaiting a new heart.
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