title: Relationship between low response to clopidogrel and periprocedural ischemic events with coil embolization for intracranial aneurysms.
abstract: OBJECTIVE
  Low response to antiplatelet drugs is one of the risk factors for ischemic events. We examined the influence of low response to clopidogrel on symptomatic ischemic events and new ischemic MRI lesions with endovascular intracranial aneurysmal coil embolization.
  
  
  METHODS
  Between August 2010 and July 2013, 189 procedures in 181 consecutive patients who underwent endovascular coiling and received clopidogrel before treatment were investigated retrospectively. Platelet aggregation activity was examined by VerifyNow analysis. Low response to clopidogrel was defined as P2Y12 reaction units ≥230 in this study. Symptomatic ischemic complications within 30 days and postoperative new ischemic lesions on MRI-diffusion weighted imaging were evaluated.
  
  
  RESULTS
  66 of 189 (34.9%) cases were low responders to clopidogrel. Ischemic complications occurred in 2 of 66 (3.0%) low responders compared with 6 of 123 (4.9%) responders (p=0.72). A new high intensity spot larger than 5 mm was significantly more frequent in low responders (26 of 66; 39.4%) than in responders (26 of 121; 21.2%; p=0.01). On multivariate analysis, independent risk factors for larger new ischemic lesions were low response to clopidogrel, smokers, posterior location, and aneurysms with a larger neck.
  
  
  CONCLUSIONS
  Low response to clopidogrel had little effect on clinical outcome although it increased asymptomatic large ischemic lesions in this cohort.
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Asai
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan Department of Neurosurgery and Endovascular Neurosurgery, Osaka Medical College, Takatsuki, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Miyachi
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Izumi
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Matsubara
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan Department of Neurosurgery, Toyohashi Municipal Hospital, Toyohashi, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Haraguchi
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamanouchi
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ota
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Shintai
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Tajima
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Wakabayashi
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology / Q000628:therapy; D000077144:Clopidogrel; D038524:Diffusion Magnetic Resonance Imaging / Q000639:trends; D004621:Embolization, Therapeutic / Q000379:methods / Q000639:trends*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D019990:Perioperative Care / Q000379:methods / Q000639:trends*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D012189:Retrospective Studies; D012307:Risk Factors; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine
keywords: Aneurysm; Coil; Drug; Embolic; MRI