Liberal blood transfusion doesn’t reduce poor outcomes in high cardiac risk patients

Editor's note

A liberal blood transfusion strategy after major vascular or general surgery for patients at high risk of a cardiac event did not reduce 90-day death or major ischemic outcome rates compared with a restrictive strategy, according to results from the Transfusion Trigger after Operations in High Cardiac Risk Patients (TOP) randomized controlled trial published November 8 in JAMA.

Postoperative anemia can cause poorer postoperative outcomes. While a restrictive blood transfusion approach is currently recommended for most stable, hospitalized patients with anemia, optimal transfusion threshold is less defined for patients at high risk of cardiac events, especially after major operative procedures, per the report. To investigate the safety of liberal (transfusion trigger at hemoglobin level <10 g/dL) versus restrictive (transfusion trigger at hemoglobin <7 g/dL) blood transfusion strategies, the TOP trial examined 1428 veterans at high risk of postoperative cardiac events who received blood transfusions based on a liberal or restrictive strategy after major operative interventions. Within the liberal group, 198 patients received 1 unit of blood, and 468 patients received 2 or more units after randomization. In the restrictive group, 548 patients did not receive any blood.

The 90-day composite findings of all-cause death, myocardial infarction, coronary revascularization, acute renal failure, or ischemic stroke occurred in 61 patients in the liberal group compared with 71 in the restrictive group. Death at 90 days was similar across groups. The investigators reported that coronary revascularization occurred in 8 of 643 patients in the liberal group and 13 of 688 patients in the restrictive group. Acute kidney failure rates were higher in the restrictive group when compared to the liberal group. However, these findings were not statistically significantly different. The 90-day composite of non–myocardial infarction cardiac complications such as new cardiac arrhythmias, heart failure, and nonfatal cardiac arrest at 90 days was significantly lower in the liberal group versus the restrictive group.

Based on these findings, the investigators concluded that after major vascular or general surgery operations among patients at high risk of a cardiac event, a liberal transfusion strategy did not reduce 90-day death or major ischemic outcome rates compared with a restrictive strategy.