The risks of death and rejection after a heart transplant for people with advanced cardiac sarcoidosis were similar to those of patients who had a transplant for other types of heart disease, according to an analysis of a registry of transplant recipients.
These results suggest that a heart transplant is a safe and effective option for patients with advanced cardiac sarcoidosis, the researchers reported.
“We found no difference in short- or long-term mortality and other post [heart transplant] results,” they wrote.
The analysis was published in the journal ESC heart failurein the study, “Outcomes after heart transplantation in patients with cardiac sarcoidosis.”
In sarcoidosis, an overactive immune system leads to the formation of clumps of inflammatory immune cells, called granulomas, in different tissues and organs. Over time, these granulomas may calcify or resemble bone, causing permanent damage.
When it comes to the heart – cardiac sarcoidosis (CS) – electrical conduction abnormalities, irregular heartbeats and heart failure can occur. As the disease progresses, scar tissue forms, requiring more advanced treatments such as heart transplantation.
Case reports suggest that a heart transplant is a feasible and effective option for people with advanced cardiac sarcoidosis. A previous heart transplant study, involving 148 patients with cardiac sarcoidosis and more than 30,000 patients without this type of rare disease, showed similar results.
Now, a team led by researchers from the Mayo Clinic in Minnesota has studied the short- and long-term outcomes of heart transplants in a newer group of patients with cardiac sarcoidosis.
“To our knowledge, this is the largest cohort [group] used to examine the outcomes of CS patients undergoing [heart transplant]“, wrote the researchers.
Data were collected from the United Network for Organ Sharing (UNOS) Scientific Registry of Transplant Recipients. The team identified 239 patients with cardiac sarcoidosis who underwent heart transplantation between 1990 and 2020 in the United States. These patients had a mean age of 52.2 years and 64% were men.
For comparison, the researchers included some 1,400 heart transplant patients with nonischemic restrictive cardiomyopathy and more than 28,000 with nonischemic dilated cardiomyopathy.
Nonischemic restrictive cardiomyopathy includes all causes of reduced heart function, other than those caused by heart attacks or blockages in the arteries of the heart (ischemia). Nonischemic dilated cardiomyopathy refers to a disease of the heart muscle that causes the left ventricle to stretch abnormally, preventing the heart from pumping blood efficiently.
The analysis showed that the incidence rate of all-cause mortality, or death from any cause, was 5.3 per 1,000 patient-years – sum of all events divided by time – for people with cardiac sarcoidosis, 6.8 for patients with nonischemic restrictive cardiomyopathy, and 5.9 for nonischemic dilated cardiomyopathy.
The median survival of heart transplant patients with cardiac sarcoidosis was 15.8 years, 13 years for nonischemic dilated cardiomyopathy and 11.7 years for restrictive cardiomyopathy.
In a simple statistical calculation, the all-cause mortality rates of patients with cardiac sarcoidosis were not different from either cardiomyopathy comparison group.
A more complex statistical calculation was then performed, adjusted for factors that could influence the results, including age, ethnicity, diabetes, body fat content and early treatments. Other factors such as ECMO treatment – which pumps blood through an artificial lung and back – mechanical ventilation at the time of transplant, as well as the age and gender of the heart donor were also considered. . Here, all-cause mortality rates remained similar across all three groups.
While 30-day mortality did not change significantly over time, there was a trend of reduced mortality rates after one year in those who had transplants more recently. Specifically, the rates were 26.7% between 1990 and 1999, 18.2% between 2000 and 2009, and 9.4% between 2010 and 2020.
Overall, 4% of patients died within 30 days of transplant and 10.3% died within a year. An adjusted analysis showed no difference in mortality rates in the three groups at 30 days and after one year.
Among a group of 163 patients with cardiac sarcoidosis, 32 (19.6%) experienced tissue rejection within the first year after transplantation. The adjusted analysis demonstrated that the risk of rejection in patients with cardiac sarcoidosis was similar to that of the other two transplant groups.
Although cardiac sarcoidosis participants were less often admitted to hospital for acute rejection (19.8% versus 28.9% in the dilated cardiomyopathy groups and 21.4% in the restrictive cardiomyopathy groups), a adjusted calculation showed that the risk of hospitalization for organ rejection was similar in the three groups.
Hospitalization rates for all infections were also similar regardless of heart disease, as were those for post-transplant lymphoproliferative disorder – the most serious complication of a transplant due to a weakened immune system.
Finally, severe graft failure causing death in the first 30 days after heart transplant did not differ significantly between the groups. There was no increased risk of death from graft failure during the first 30 days in the adjusted analysis.
“This analysis of the UNOS registry showed that the risks of all-cause mortality and rejection in the short and long term after [heart transplant] were not inferior in sarcoid cardiomyopathy compared to other common types of non-ischemic cardiomyopathy,” the team concluded.
“These data suggest that [heart transplant] may be safe and effective in this growing population of patients with [heart transplant] because of CS,” they added.