Risk factors for fluid retention associated with clazosentan after subarachnoid hemorrhage: a retrospective study

Objectives: Clazosentan, a drug used to prevent delayed cerebral vasospasm, is frequently associated with fluid retention-related adverse events (AEs), such as pulmonary edema. This study aimed to identify risk factors for fluid retention associated with clazosentan administration. Methods: A retrospective study was conducted involving patients admitted with aneurysmal subarachnoid hemorrhage to the Emergency and Critical Care Center of Nihon University Hospital between May 2022 and June 2024. Fluid retention-related AEs were defined as Grade 2 or higher according to the Common Terminology Criteria for Adverse Events version 5.0. Patient characteristics were compared between the fluid retention and non-fluid retention groups, and binomial logistic regression analysis was performed to identify risk factors. Results: Among the 32 patients enrolled, 15 developed fluid retention, whereas 17 did not. Significant risk factors for fluid retention included age (odds ratio [OR]: 1.11, 95% confidence interval [CI]: 1.01–1.22, p = 0.026) and the average daily fluid balance from admission to the third day after initiation of clazosentan (OR: 1.01, 95% CI: 1.00–1.02, p = 0.025). Receiver operating characteristic curve analysis indicated a cutoff value of 68 years for age (sensitivity 67%, specificity 88%, and area under the curve [AUC] 0.76) and 560 mL/day for average fluid balance (sensitivity 87%, specificity 82%, and AUC 0.90). Conclusion: Older age and early fluid accumulation emerged as significant risk factors for fluid retention in patients treated with clazosentan. In older individuals, close monitoring and careful fluid balance management may help prevent clazosentan-associated complications.