Clinical Burden of Angiographic Vasospasm and Its Complications After Aneurysmal Subarachnoid Hemorrhage: A Systematic Review

Introduction: Angiographic vasospasm (VSP), the narrowing of intracranial arteries, is a complication of aneurysmal subarachnoid hemorrhage (aSAH) and often results in delayed cerebral ischemia (DCI) and cerebral infarction. The objective of this systematic review was to summarize the clinical burden of angiographic VSP and its related complications (DCI and cerebral infarction) after aSAH.Methods: Systematic searches of MEDLINE, Embase, and the Cochrane Library were conducted (in January 2021) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify studies reporting clinical outcomes of angiographic VSP and its related complications after aSAH. Study outcomes included measures of functional status (modified Rankin Scale [mRS], Glasgow Outcome Scale [GOS], extended Glasgow Outcome Scale [GOS-E], modified Barthel Index, or the modified National Institutes of Health Stroke Scale), cognitive status (Montreal Cognitive Assessment or the Mini Mental State Exam), clinical events (rebleeding), and mortality. Study selection, data extraction, and qualitative analyses were conducted.Results: Of 5704 abstracts reviewed, 110 studies were selected: 20 comparative and 39 regression-based studies were included in the qualitative synthesis, 51 descriptive studies were excluded. Most studies (51) were observational and conducted in a single country (53). The occurrence of angiographic VSP and its related complications after aSAH resulted in significantly poorer functional outcomes in three of nine comparative and 11 of 13 regression-based studies, measured by the mRS, and in five of six comparative and eight of nine regression-based studies, measured by the GOS and GOS-E. Angiographic VSP and its related complications were significantly associated with poor cognitive status in all five regression-based studies. Numerically or significantly higher mortality rates in patients with versus those without angiographic VSP and its related complications were reported in five of ten comparative studies and in eight of nine regression-based studies. Six studies looked at specific VSP populations (e.g., by severity or timing of VSP).