After a first partial heart transplant on an infant in 2022, a team from the University of Duke (Durham, United States) reports in the Jama A series of 18 other cases of patients who have since benefited from a partial cardiac transplant for congenital heart disease. Researchers conclude that a method “Sure and achievable” allowing valvular growth and thus representing “A promising solution to overcome the limits of current non -scalable valve replacement options”, under cover of an immunosuppressive maintenance treatment.
However, the authors warn that “Partial cardiac transplantation is not a panacea, but rather a promising advance that requires being perfected”. Before adding that “Additional research is necessary to fully understand its long -term implications and refine its application to a wider range of congenital cardiac malformations”.
The first clinical case described by the team was that of an infant born with a common arterial trunk having benefited from a partial heart transplant at 18 days. One year of follow -up, the team had found that the graft accompanied the growth of the child, and that the latter was in good health and without delay in development. Until then, the standard treatment of a severe valvulopathy-with around 50 % of ultimately survival-rested either on a total heart transplant, or on a homogreffe of cryoprids cardiac valve from a deceased donor (having then lost its growth capacity), which must be replaced regularly during the growth of the child until the implantation of an adult size. With the partial core transplant, it is the part of the heart with the faulty valve (s) which is transplanted and growing with the child.
A favorable security profile
In this series, 19 patients (53 % of boys) who had a congenital heart valve dysfunction were operated in the Pediatric Cardiac Surgery Center of the University of Duke between April 2022 and December 2024. The median age at the time of transplantation was 97 days [2-34]. Among the pathologies found: arterial common trunk, Fallot tetralogy, severe aortic stenosis, severe aortic insufficiency, obstruction of ventricular ejection … Patients have thus benefited from different partial transplants. The main judgment criterion was the growth of the ring and valve sheets during follow -up. Valvular dysfunctions and complications related to immunosuppression were considered to be secondary criteria.
At the end of a 26 -week median follow -up, all the valves have demonstrated functional sustainability and uniform growth over time with an immunosuppressive maintenance of maintenance by tacrolimus. Thus, the annular diameter has gone from a median of 7 to 14 mm for the aortic valves and from 9 to 17 mm for the pulmonary valves; The leaf length increased from 0.5 to 1 mm and from 0.49 to 0.675 mm respectively. No patient has undergone a reoperation linked to the valve, but a patient has been reoperated unrelated to the established valve. Finally, no significant complication linked to immunosuppression has been observed.
Outstanding questions
With these promising results, the authors emphasize that the question of optimal immunosuppression strategies is still to be explored. However, “This could be achievable given the low quantity of myocardium of the donor involved in partial cardiac transplantation and the relative immune privilege of the heart valves compared to the myocardial tissue”.
In addition, among the 19 patients, one was finally able to do without maintenance immunosuppression. And the authors add that cases of chimerism could be observed in these cases of partial transplants, thus making it possible to reduce the immunosuppression.
Finally, researchers believe that partial transplant will not be confined to the Sigmoid valves and can be practiced for other heart tissues.
