Earlier Blood Transfusion Timing May Reduce Heart Failure and Arrhythmia Risk in Cardiac Patients After Surgery

The timing of blood transfusions after major surgery may significantly impact the risk of heart failure and irregular heartbeat in patients with pre-existing heart disease, according to new research presented at the American Heart Association's Scientific Sessions 2025. The Transfusion Trigger after Operations in High Cardiac Risk Patients (TOP) trial investigated whether transfusing blood earlier, when hemoglobin levels drop below 10 g/dL after major surgery, might prevent complications better than waiting until hemoglobin levels drop below 7 g/dL, which represents the current standard of care for most patients.

This study of more than 1,400 military veterans undergoing major general or vascular surgery found that while earlier transfusion timing did not affect the risk of severe complications such as death, heart attack, kidney failure, need for heart procedures or stroke, it substantially reduced the occurrence of heart failure and irregular heart rhythms. Patients in the early transfusion group experienced these complications at a rate of 5.9% compared to 9.9% in the later transfusion group, representing a 41% lower risk. Severe complication rates remained similar between groups at 9.1% versus 10.1% respectively.

Lead author Panos Kougias, M.D., M.Sc., chair of the department of surgery at SUNY Downstate Health Sciences University, explained that persistent blood loss in patients with serious underlying heart issues might place greater strain on the heart than the volume from a transfusion. The traditional thinking has been that giving more blood could potentially overload the heart and worsen failure, but these findings suggest the opposite may be true for high-risk cardiac patients. The study was simultaneously published as a full manuscript in the peer-reviewed scientific journal JAMA.

The trial included veterans receiving care at 16 Veterans Affairs Medical Centers throughout the United States, with participants enrolled between February 2018 and March 2023. Participants had an average age of 70 years, with 98% being men and 75% self-identifying as white adults. Researchers measured hemoglobin levels after surgery and after each transfusion, following participants for 90 days after their procedures. The American Heart Association provides additional scientific information through their official website and maintains strict policies to ensure scientific integrity.

These findings challenge the current one-size-fits-all approach to transfusion timing and suggest that for patients with serious underlying heart disease undergoing major surgery, earlier blood transfusion could help prevent serious heart complications other than heart attack. However, the study authors note that as this was a secondary outcome, further research will be needed to confirm these findings. Study limitations include the predominantly male participant population and the fact that healthcare professionals knew which transfusion strategy patients received, which may have affected care decisions.