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 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 U.S. military veterans receiving care at 16 Veterans Affairs Medical Centers between February 2018 and March 2023. Participants averaged 70 years old, with 98% being men and 75% self-identifying as white adults. Researchers followed patients for 90 days after surgery, assessing hemoglobin levels after each procedure and subsequent transfusion.

While severe complication rates including death, heart attack, kidney failure, need for heart procedures or stroke were similar between groups at 9.1% in the early transfusion group versus 10.1% in the later transfusion group, the study revealed significant differences in heart-specific complications. Irregular heart rhythms and heart failure occurred in 5.9% of patients receiving earlier transfusions compared to 9.9% in the later transfusion group, representing a substantial 41% lower risk.

Lead author Panos Kougias, M.D., M.Sc., chair of the department of surgery at SUNY Downstate Health Sciences University, explained the implications. "Our findings suggest that persistent blood loss in patients with serious underlying heart issues might place a greater strain on the heart than the volume from a transfusion, leading to problems like heart failure and irregular heartbeat," Kougias said. "The earlier blood transfusion strategy may protect the heart from the effects of blood loss."

The findings challenge conventional thinking that giving more blood might potentially overload the heart and worsen failure. Instead, the research suggests that for high-risk cardiac patients, persistent anemia might strain the heart more than transfusion volume. The study was simultaneously published as a full manuscript in the peer-reviewed scientific journal JAMA and presented at the American Heart Association's Scientific Sessions 2025, with additional information available through the American Heart Association's Online Program Planner.

Study limitations include the predominantly male participant population, meaning results may not apply to women. Additionally, healthcare professionals knew which transfusion strategy patients received, potentially affecting care decisions. The number of severe complications was fewer than expected, meaning small differences between groups might have gone undetected. The trial was funded by the Veterans Affairs Office of Research and Development, with co-authors and disclosures listed in the abstract available here.