Liberal Transfusion Confers No Risk Reduction in Aneurysmal Subarachnoid Hemorrhage

In patients with aneurysmal subarachnoid hemorrhage and anemia, a liberal transfusion strategy resulted in a comparable risk for poor neurologic outcomes compared with a more restrictive strategy at one year, according to a study published in the New England Journal of Medicine.

A total of 725 adults at 23 centers with neurosurgical and neurointerventional support in Australia, Canada and the United States were randomized and included in the analysis. At 12 months, an unfavorable neurologic outcome occurred in 122 of 364 patients (33.5%) in the liberal-strategy group compared with 136 of 361 patients (37.7%) in the restrictive-strategy group (P = 0.22).

The authors noted that anemia occurs in more than half of patients with subarachnoid hemorrhage and is linked to worse clinical outcomes. Evidence regarding red blood cell (RBC) transfusion is limited and conflicting and has led to vague guidelines recommending maintenance of normal hemoglobin (Hb) levels and transfusion when levels drop. However, no threshold values have been delineated. The findings of the Subarachnoid Hemorrhage Red Cell Transfusion Strategies and Outcome (SAHARA) fill an important gap.

Critically ill patients with acute aneurysmal subarachnoid hemorrhage from intracranial aneurysm rupture and anemia were randomly assigned to a liberal or restrictive RBC transfusion. In the liberal strategy, transfusion was mandatory at a Hb level of less than 10 g/dL. The restrictive strategy allowed for optional transfusion at an Hb level of less than 8 g/dL. While the trial was open-label, outcome assessment was blinded. Leukoreduced RBCs were administered one unit at a time. The mean age was 59.4 years, and the patients were 82% women. The median pretransfusion Hb level was 9.6 g/dL and 7.6 g/dL in the liberal and restrictive strategy groups, respectively. 

Unfavorable neurologic outcome at 12 months— the primary outcome — was defined as a score of 4 or greater on the modified Rankin scale, which ranges from 0 to 6. Higher scores indicate greater disability. Secondary outcomes included functional independence at 12 months, as assessed with the Functional Independence Measure (FIM), and quality of life as assessed with the EuroQol five-dimension, five-level (EQ-5D-5L) utility index and a visual analogue scale (VAS).

The mean FIM score (range 18 to 126) was 82.8 ± 54.6 in the liberal-strategy group and 79.8 ± 54.5 in the restrictive strategy group. In terms of quality of life, the mean EQ-5D-5L utility index score was 0.5 ± 0.4 in both groups (range -0.1 to 0.95). Similarly, the mean VAS score was 52.1 ± 37.5 and 50 ± 37.1 in the liberal- and restrictive-strategy groups, respectively (range 0-100). Adverse event incidence was similar for both groups.