Speakers
Panos Kougias, MD, MSc
Professor and Chair
Department of Surgery, SUNY Downstate Health Sciences University
Sherene Sharath, PhD, MPH
Assistant Professor
Department of Surgery, SUNY Downstate Health Sciences University
Keywords
Blood Transfusion; Surgery; Cardiology; Cardiac Outcomes
Key Points
- Postoperative anemia is common after major operations. While the current guidelines recommend transfusion for hemoglobin (Hb) below 7 g/dL, the safety of this restrictive strategy is unclear – particularly after major operations and in high cardiac risk patients.
- The study team sought to evaluate whether a more liberal transfusion strategy reduces the risk of mortality or major ischemic events in high cardiac risk patients undergoing major operations. They randomized eligible veterans from 16 VA medical centers to receive transfusion at either Hb<10 g/dL (the “liberal” arm) or Hb<7 g/dL (the “restrictive” arm).
- They found that the rates of mortality and major ischemic events were similar between the groups. While the rates of most secondary outcomes were also similar, a composite outcome of heart failure and arrhythmias was more frequent in the restrictive arm.
- The study team noted that a one-size-fits-all approach may not be applicable for transfusion strategies. Potential cardiac-outcome related benefits should be explored in future trials.
Discussion Themes
In the weighting of composite outcomes, the analysis treated all events (e.g., death vs. minor complications) as having equal clinical severity. This may have reduced the trial’s statistical power.
The actual event rate (10%) was much lower than the anticipated 30%. The study team attributed this to improved perioperative care and better cardiovascular outcomes over the last decade compared to the historical data used for initial calculations.
Communicating nuanced findings may require some extra legwork; clinicians often struggle to interpret results that are not clear-cut “wins” or “losses.”