According to a study by researchers at Johns Hopkins, heart transplant patients are considerably more likely to survive at least a decade after their operation if they underwent the procedure before the age of 55 at a hospital that performs at least 9 heart transplants per year. The study is published in the March issue of The Annals of Thoracic Surgery.
The researchers analyzed data collected by the United Network of Organ Sharing (UNOS) from over 22,000 adults in the U.S. who underwent heart transplant between 1987 and 1999. They found that 10 years after transplantation, approximately half of all patients were still alive. In addition further examination identified factors that seem to predict at least 10 years of life following the procedures.
Arman Kilic, M.D., a surgical resident at The Johns Hopkins Hospital and leader of the study explained:
"There are 2,000 to 2,500 heart transplants a year in the U.S. and many people die waiting. We have to be very smart about how to allocate scarce organs, and our research suggests we can predict which patients will live longer with a new heart."
The team used the UNOS data and compared the 9,404 heart transplant recipients who survived for 10 years or more with the 10,373 heart transplant recipients who did not. Approximately 3,000 patients were lost to follow-up.
- Heart transplant recipients who underwent the procedure at a hospital that performed 9+ heart transplants a year had a 31% greater 10-year survival chance than those at lower volume centers.
- Patients who underwent the procedure at age 55 of younger had a 25% greater chance of 10-year survival than older patients.
- White heart transplant recipients were 35% more likely to survive 10-years compared with minority patients.
"After the age of 55, we see the biggest difference in long-term survival. The chance of surviving for 10 years drops precipitously."
Kilic says that individuals who receive heart transplant at a hospital that performs over 9 heart transplants a year do better not just because their surgeons are likely to have more experience with the procedure, but also because the hospital and staff are likely to be better equipped to manage the complex post-operative care these patients require and promote good outcomes.
In addition, the researchers found that patients were 47% more likely to die within 10 years of surgery if there were on ventilators prior to their procedure. Patients who need ventilators prior to surgery are considerably sicker than patients who don't require ventilators, so it's logical that those patients would do poorly. The team also discovered that patients who were diabetic were one-third more likely to die within 10 years of transplant.
Results from the study also reveal the impact on long-term survival of ischemic time (the duration of time the heart is out of the body as it travels from donor to recipient). They found that there was an 11% increase in the recipients 10+ year survival chance for each hour ischemic time was reduced.
In addition, for each 10 years younger the donor was, the recipient was 10% more likely to survive long term, revealed Kilic.
Under current regulations and policies, UNOS gives available hearts to patients on its national waiting list who are the sickest, generally to patients who are predicted to not survive a month without transplantation. Although Kilic agrees with the policies, he explains that it may be helpful to use his data in order to prioritize the sickest patients who are more likely to survive the longest.
"These data could be used for both prognosis and allocation purposes. They help predict which patients have the best chance to derive the longest and most sustainable benefit from the limited number of hearts that become available each year. It also identifies areas that need further research, such as why racial disparities exist in long-term survival following heart transplant."
In the U.S., over 5 million people experience heart failure, and even though medication and lifestyle modifications can help the majority of these patients, heart transplantation remains the gold standard treatment for those who suffer from severe, end-stage heart failure.
Other researchers of the study include Timothy J. George, M.D.; George J. Arnaoutakis, M.D.; Ashish S. Shah, M.D.; and John V. Conte, M.D.
Written by Grace Rattue