title: Safety and efficacy of endovascular thrombectomy in patients with abnormal hemostasis: pooled analysis of the MERCI and multi MERCI trials.
abstract: OBJECTIVE
  Patients with abnormal hemostasis are not considered candidates for thrombolysis. We analyzed the MERCI/Multi MERCI cohort as an attempt to establish the risks and benefits of thrombectomy in this patient population.
  
  
  METHODS
  Two patient groups were identified: Group 1 (n=35): patients with INR >1.7 or PTT >45 seconds or platelet count <100,000/microL; Group 2 (n=270): patients with INR <or=1.7, PTT <or=45 seconds, and platelet count >or=100,000/microL. Clinical, radiographic, and revascularization outcomes were subsequently compared.
  
  
  RESULTS
  In Group 1, 20 patients had INR >1.7 (mean: 2.4; range: 1.8 to 4.9), 11 had PTT >45 seconds (mean: 95; range: 46 to 190), and 6 had platelets <100,000/microL (mean: 63 400; range: 16,000 to 94,000). Two patients had both INR >1.7 and PTT >45 seconds. The two groups did not significantly differ in terms of age, gender, baseline NIHSS scores, intraarterial thrombolytic use/dosage, or occlusion site. Time-to-treatment was slightly earlier in Group 1. There was no significant difference in the rates of revascularization (TIMI 2 to 3: 60% versus 65%), mortality (40% versus 38%), or major symptomatic intracranial hemorrhage (SICH; 8.6% versus 8.5%). Group 2 had higher rates of good clinical outcomes (9% versus 35%; P=0.002). This was likely related to a lower prestroke health status in Group 1 patients. In Group 1, successful revascularization was associated with improved outcomes (P=0.015) and lower mortality (24% versus 64%; P=0.033).
  
  
  CONCLUSIONS
  Patients with abnormal hemostasis who undergo thrombectomy do not appear to be at a higher risk for SICH but have lower rates of good outcomes. In this patient group, successful revascularization appears to be associated with improved clinical outcomes and lower mortality.
authors.affiliation: Departments of Vascular & Critical Care Neurology and Interventional Neuroradiology & Endovascular Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA. rnogueira@partners.org
authors.forename: Raul G
authors.initials: RG
authors.lastname: Nogueira
authors.forename: Wade S
authors.initials: WS
authors.lastname: Smith
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000000981:diagnostic imaging; D002533:Cerebral Angiography; D002543:Cerebral Hemorrhage / Q000453:epidemiology / Q000601:surgery; D015331:Cohort Studies; D003625:Data Collection; D005260:Female; D020141:Hemostatic Disorders / Q000503:physiopathology*; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000473:pathology; D010314:Partial Thromboplastin Time; D010976:Platelet Count; D012189:Retrospective Studies; D018570:Risk Assessment; D017131:Thrombectomy / Q000009:adverse effects; D013927:Thrombosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome