Transfusion Strategies in High Cardiac Risk Postoperative Patients: Insights from the TOP Trial

Managing postoperative anemia in patients with preexisting cardiovascular disease presents a clinical challenge. While restrictive transfusion thresholds (hemoglobin <7 g/dL) are standard in critical care, their safety in high-risk cardiac patients undergoing major surgery remains uncertain. The Transfusion Trigger After Operations in High Cardiac Risk Patients (TOP) trial offers new evidence to refine transfusion strategies in this population.

The TOP Trial: Summary and Findings

The TOP trial randomized 1,428 veterans with significant cardiac comorbidities following major vascular or general surgery to either a liberal transfusion strategy (triggered at hemoglobin <10 g/dL) or a restrictive strategy (<7 g/dL). The primary outcome—a 90-day composite of death, myocardial infarction, ischemic stroke, revascularization, or acute kidney injury—occurred in 9.1% of the liberal group and 10.1% of the restrictive group (RR 0.90, 95% CI 0.65–1.24), showing no significant difference.

However, secondary outcomes revealed that cardiac complications excluding myocardial infarction—namely arrhythmias, new or worsening heart failure, and nonfatal cardiac arrest—were significantly more frequent in the restrictive group (9.9% vs. 5.9%, RR 0.59, 99% CI 0.36–0.98). A post hoc analysis that included myocardial infarction yielded a non-significant trend favoring liberal transfusion. Notably, hemoglobin separation between groups was substantial (~2 g/dL), and protocol adherence was high, reinforcing internal validity.

Despite receiving more transfusions, the liberal group did not experience higher rates of adverse events, and 90-day mortality was similar in both arms. The unexpected higher heart failure rate in the restrictive group suggests that sustained anemia may provoke myocardial dysfunction in patients with compromised cardiac reserve.

Clinical Implications

The results support the continued use of restrictive transfusion in most stable, postoperative patients. However, in patients with ischemic heart disease, symptomatic heart failure, arrhythmias, or recent coronary events, a liberal strategy may reduce cardiac complications. Transfusion decisions should be individualized based on symptoms, hemodynamics, cardiac risk profile, and physiologic markers. Rigid hemoglobin thresholds may not suffice in guiding safe transfusion in this complex cohort.

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References

1. Jacobs JW, Bloch EM. Postoperative Transfusion in Patients at High Cardiac Risk. JAMA. 2025. doi:10.1001/jama.2025.21559. Link

2. Kougias P, et al. Liberal or Restrictive Postoperative Transfusion in Patients at High Cardiac Risk: The TOP Randomized Clinical Trial. JAMA. 2025. doi:10.1001/jama.2025.20841. Link