Liberal versus restrictive transfusion strategies in subarachnoid hemorrhage: a secondary analysis of the TRAIN study.

Summary

In a pre-planned secondary analysis of SAH patients within the TRAIN RCT, a liberal transfusion threshold (Hb <9 g/dL) did not significantly reduce unfavorable outcomes at 180 days versus a restrictive threshold (Hb <7 g/dL) in unadjusted analyses. However, liberal strategy was associated with less cerebral ischemia and, after adjustment, with a lower risk of unfavorable outcome.

Key Findings

• Randomized comparison within TRAIN: liberal (Hb <9 g/dL) vs restrictive (Hb <7 g/dL) transfusion in 190 SAH patients.
• Unfavorable outcome at 180 days: RR 0.87 (95% CI 0.71–1.04) for liberal vs restrictive (not statistically significant).
• Cerebral ischemia significantly lower with liberal strategy: RR 0.63 (95% CI 0.41–0.97).
• Adjusted analysis associated liberal randomization with lower risk of unfavorable outcome: RR 0.83 (95% CI 0.70–0.99).

Clinical Implications

For neuroanesthesiology and neurocritical care, considering a more liberal transfusion threshold may reduce cerebral ischemia risk in SAH. Patient blood management protocols could individualize thresholds, especially in patients at high risk of delayed cerebral ischemia.

Limitations

• Secondary analysis; potential for residual confounding despite adjustment.
• Liberal group was older; imbalances may influence outcomes.
• Trial not primarily powered for SAH subgroup alone.

Future Directions

A definitive SAH-specific RCT comparing transfusion thresholds with cerebral ischemia and functional outcomes as co-primary endpoints is warranted; mechanistic monitoring (e.g., brain tissue oxygenation) could guide individualized thresholds.