Vasospasm risk following aneurysmal subarachnoid hemorrhage in older adults

Objective: Cerebral arterial vasospasm is a dreaded sequela of aneurysm rupture and can result in significant narrowing of the surrounding vasculature and subsequent cerebral ischemia. Treatment interventions are associated with distinct side effect profiles, including the risk of thrombosis and worsened ischemia, which may be associated with increased mortality-especially in older adults. An improved understanding of the likelihood of vasospasm in elderly patients would enable clinicians and patients to better consider the risks and benefits of vasospasm prophylaxis in this vulnerable population. This retrospective chart review aimed to assess the relationship between age at onset and the incidence of cerebral vasospasm among patients treated at the University of North Carolina Medical Center with spontaneous aneurysmal subarachnoid hemorrhage (aSAH).

Methods: Electronic health record data from the Epic Systems Corp. database, compiled by the Carolina Data Warehouse for Health, were analyzed for patients older than 18 years who were previously treated for an SAH secondary to aneurysm at the University of North Carolina Medical Center within the past 10 years, ranging from June 2011 through June 2021. Logistic regression was used to calculate odds ratios and to determine the association of age with the occurrence of vasospasm following aSAH.

Results: Of the 386 cases analyzed, 149 patients (38.6%) were older than 65 years at the time of aSAH. A total of 192 of the 386 patients (49.7%) developed vasospasm within the first 3-21 days following aSAH. Among the patients who developed vasospasm, only 31 of 192 patients (16.1%) were older than 65 years at the time of aneurysm rupture. Odds ratio calculations revealed that older adults (> 65 years) were 8 times less likely to develop vasospasm compared to their younger counterparts (p < 0.0001; 95% CI 5.0-13.0).

Conclusions: This study found that older patients are less likely to develop cerebral vasospasm following aSAH than are younger individuals. Age-associated changes in arteriosclerosis, inflammatory responses, and CSF dynamics may mitigate vascular narrowing in response to aSAH. This finding suggests that the aSAH treatment and vasospasm prevention paradigms should be revised to minimize potentially unnecessary interventions and avoid adverse outcomes for older adults.