Factors Influencing Discontinuation of Clazosentan Therapy in Elderly Patients with Aneurysmal Subarachnoid Hemorrhage: A Retrospective Study from a Japanese Single Center.

BACKGROUND Clazosentan is an endothelin receptor antagonist approved in Japan for preventing cerebral vasospasm and vasospasm-associated cerebral ischemia and infarction. This study included elderly patients aged ≥75 years with aneurysmal subarachnoid hemorrhage (SAH) and aimed to evaluate the factors associated with discontinuing anti-vasospasm therapy with clazosentan. MATERIAL AND METHODS In this single-center retrospective observational study, we extracted diagnostic and therapeutic work-up data of consecutive 40 patients with SAH treated with clazosentan infusion (10 mg/h) as first-line anti-vasospasm therapy between May 2022 and August 2023. Patient data were compared between the discontinued and completed groups, and related factors for the discontinuation were further analyzed. RESULTS Clazosentan was discontinued in 22% (n=9) of patients due to intolerable dyspnea accompanied by hypoxemia at 5±3 days after therapy initiation, in which 44% (n=4) were elderly (≥75 years). Patients who discontinued clazosentan therapy showed significantly lower urine volumes compared with those who completed the therapy (P<0.05). Multivariate regression analysis revealed that day-to-day urine volume variance and older age were independent risk factors for drug cessation (P<0.05). The cut-off value for predicting clazosentan discontinuation was -0.7 mL/kg/h with sensitivity of 86% and specificity of 75% (area under the curve: 0.76±0.10; 95% confidence interval: 0.56-0.96; P=0.035). CONCLUSIONS Our results suggest that approximately 20% of SAH patients suffered from intolerable respiratory symptoms attributable to hypoxemia. We found that both reduced day-to-day urine volume variation and older age are independent risk factors for drug discontinuation.

Cardiopulmonary Events of the Elderly (≥75 Years) during Clazosentan Therapy after Subarachnoid Hemorrhage: A Retrospective Study from a Tertiary Stroke Center in Japan.

Clazosentan has been shown to prevent vasospasm and reduce mortality in patients after aneurysmal subarachnoid hemorrhage (SAH) and has been approved for clinical use in Japan; however, its systemic events in the elderly (aged ≥ 75 years) have not been well-documented. Here, we report serious/intolerable cardiopulmonary complications requiring discontinuation of drug therapy in elderly SAH patients. In this single-center case series study, medical records of consecutive SAH patients treated postoperatively with clazosentan (10 mg/h) between June 2022 and May 2023 were reviewed retrospectively. Thirty-three patients received clazosentan therapy, of whom six were elderly with a mean age of 80.3 ± 5.2 (range 75-89) years. Among them, despite no obvious medical history of systemic abnormalities, clazosentan was discontinued in three (50%) patients due to pleural effusion and hypoxemia with or without hypotension at 5 ± 3 days after therapy initiation, which was higher than the incidence for younger patients (15%). The elderly patients had significantly lower urine output (1935 ± 265 vs. 1123 ± 371 mL/day, p = 0.03) and greater weight gain (2.1 ± 1.1 vs. 4.2 ± 1.9 kg from baseline, p = 0.04) than patients who completed the therapy. One 89-year-old female developed congestive heart failure and hydrostatic pulmonary edema associated with increased intravascular and lung volumes even after therapy was discontinued, while the remaining two cases recovered within 2 days after drug cessation. These results suggest that elderly patients are more vulnerable to fluid retention and have a higher risk of cardiopulmonary complications during clazosentan therapy than younger patients. Careful monitoring of urine volume and weight gain and caution regarding age- and therapy-related hemodynamic insufficiencies are required.

ATP increases the migration of microglia across the brain endothelial cell monolayer.

The cerebral microcapillary endothelium, known as the blood-brain barrier (BBB), acts as a barrier between the blood and the interstitial fluid of the brain. The BBB therefore controls the passage of nutrients into the central nervous system (CNS). Microglia show a specific affinity for migration into the CNS, and this migration appears to occur independently of BBB integrity. To study the migration of microglia across the BBB, we developed an in vitro co-culture system of mouse brain endothelial cells (MBECs) and Ra2 microglia using Transwell inserts. We first investigated the influence of microglia or ATP, a microglial chemotactic factor, on MBEC barrier integrity. The addition of microglia or ATP led to the disruption of the MBEC monolayer and significantly decreased barrier function as measured by trans-endothelial electrical resistance (TEER) and electric cell-substrate impedance sensing (ECIS). Furthermore, ATP promoted the migration of microglia but not macrophages across the MBEC monolayer. An inhibitor of matrix metalloproteinases (MMPs) decreased the transmigration of microglia in our system, indicating that MMPs play a role in microglial chemotaxis. We specifically identify a role for microglia-derived MMP-2. In conclusion, we offer evidence that microglia migration across the brain endothelial cell monolayer is increased in the presence of ATP in a manner that involves MMP secretion.