Introduction: Clinical vasospasm and delayed cerebral ischemia (DCI) are devastating complications of aneurysmal subarachnoid hemorrhage (aSAH). Several theories have been postulated as potential etiologies of clinical vasospasm and DCI, involving platelet activation. However, the effects of dual anti-platelet therapy (DAPT: aspirin and clopidogrel) on clinical vasospasm and DCI have not been previously investigated. The objective of this study was to evaluate the effects of DAPT on clinical vasospasm and DCI in aSAH patients.

Methods: Analysis of patients treated for aSAH during the period from July 2009 to April 2014 was performed in a single-institution retrospective study. Patients were divided into two groups: patients who underwent stent-assisted coiling or placement of flow diverters requiring DAPT (DAPT group) and patients who underwent coiling only without DAPT (control group). The frequency of symptomatic clinical vasospasm and DCI and of hemorrhagic complications was compared between the two groups, utilizing univariate and multivariate logistic regression.

Results: Of 312 aSAH patients considered for this study, 161 patients met the inclusion and exclusion criteria and were included in the analysis (85 patients in the DAPT group and 76 patients in the control group). The risks of clinical vasospasm (OR: 0.244; CI 95% [0.097 – 0.615]; p = 0.003) and DCI (OR: 0.056; CI 95% [0.01 – 0.318]; p = 0.001) were significantly lower in patients receiving DAPT. Hemorrhagic complications associated with placement of external ventricular drains and ventriculoperitoneal shunts were similar in both groups (4% versus 2%; p = 0.9).

Conclusions: The use of DAPT was associated with a lower risk of clinical vasospasm and DCI in patients treated for aSAH without an increased risk of hemorrhagic complications.

Patient Care: The research presented provides new evidence for lowering the risk of both clinical vasospasm and DCI without increasing the risk of hemorrhagic complications through the use of DAPT in patients following treatment of aSAH.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) In small groups, discuss potential etiologies of clinical vasospasm and DCI, 2) Identify the incidence of clinical vasospasm and DCI in patients following aSAH, 3) Evaluate the effects of DAPT on clinical vasospasm and DCI in aSAH patients.

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