Stratified assessment of clazosentan efficacy following subarachnoid hemorrhage: A multi-center cohort study

There are conflicting results regarding the efficacy of clazosentan, a selective endothelin A receptor antagonist, on cerebral vasospasm after subarachnoid hemorrhage (SAH). As the effectiveness of clazosentan for patients over 75 years old and those with World Federation of Neurosurgical Societies grade V has not been established, we aimed to evaluate its efficacy in real-world clinical settings. This study utilized prospectively collected data from consecutive SAH patients across 4 stroke centers, comparing 187 patients treated with clazosentan to 223 patients receiving standard of care. The incidence of favorable functional outcomes (modified Rankin Scale score 0-2) at 90 days after SAH, occurred more frequently in patients receiving clazosentan (74.9% vs 65.0%, <i>p</i> = 0.032). Multiple logistic analyses identified clazosentan administration as independently associated with favorable functional outcomes (49.1% vs 37.6%, odds ratio 2.17 [1.22-3.85], <i>p</i> = 0.008). Angiographic vasospasm (25.7% vs 48.9%, <i>p</i> < 0.001) and vasospasm-related infarcts (11.8% vs 20.2%, <i>p</i> = 0.023) were less frequent among patients receiving clazosentan. Stratification analyses revealed that clazosentan usage increased the incidence of favorable functional outcomes regardless of age, sex, SAH severity, and clot volume. These results underscore the therapeutic potential of clazosentan against cerebral vasospasm independent of patient characteristics.