Earlier Blood Transfusions May Reduce Heart Failure Risk in Cardiac Patients After Surgery

A new study presented at the American Heart Association's Scientific Sessions 2025 suggests that earlier blood transfusions may significantly reduce the risk of heart failure and irregular heartbeat in patients with heart disease undergoing major surgery. The Transfusion Trigger after Operations in High Cardiac Risk Patients (TOP) trial investigated whether transfusing blood when hemoglobin levels drop below 10 g/dL after major surgery provides better outcomes than waiting until levels fall below 7 g/dL.

The study involved more than 1,400 military veterans receiving care at 16 Veterans Affairs Medical Centers throughout the U.S. between February 2018 and March 2023. Participants, who had an average age of 70 and were predominantly male, underwent major general or vascular surgery. Researchers monitored hemoglobin levels after surgery and following each transfusion to determine if additional transfusions were needed until discharge or 30 days post-surgery.

Lead author Panos Kougias, M.D., M.Sc., chair of the department of surgery at SUNY Downstate Health Sciences University in Brooklyn, New York, explained the significance of these findings. "When excessive blood loss or anemia occurs during or after surgery, a blood transfusion may be needed. For people with heart disease, the risk of complications due to the strain of blood loss means that the timing of a blood transfusion is critical," Kougias said. "The current standard of care for most patients is to wait until hemoglobin levels are low before transfusing blood."

The analysis revealed that severe complication rates—including death, heart attack, kidney failure, need for a heart procedure, or stroke—were similar between the two transfusion strategies. The early transfusion group had a 9.1% rate of severe complications compared to 10.1% in the later transfusion group. However, the study found a substantial difference in heart-related complications. Irregular heart rhythms and heart failure occurred in only 5.9% of patients in the early transfusion group compared to 9.9% in the later transfusion group, representing a 41% lower risk among those receiving earlier transfusions.

"We were surprised that the restrictive transfusion strategy—giving less blood by only transfusing once patients' hemoglobin levels were below 7 g/dL—was associated with a higher rate of heart failure," Kougias noted. "The traditional thinking has been that giving more blood may potentially overload the heart and worsen failure. Our finding suggests that in high-risk heart patients, persistent anemia might place a greater strain on the heart than the volume from a transfusion."

The study was simultaneously published as a full manuscript in the peer-reviewed scientific journal JAMA. The trial was funded by the Veterans Affairs Office of Research and Development, and additional resources including the abstract and the American Heart Association's Scientific Sessions 2025 Online Program Planner are available through the Association's resources.

These findings challenge current transfusion practices and suggest that a one-size-fits-all approach may not be optimal for patients with serious underlying heart disease. "For some patients, waiting to transfuse remains safe and appropriate," Kougias said. "However, for patients with serious underlying heart disease undergoing major surgery, our findings show that an earlier blood transfusion could help prevent serious heart complications, other than a heart attack." The study's limitations include the predominantly male participant population and the fact that healthcare professionals were aware of which transfusion strategy patients received, which may have influenced care decisions.