Abstract 183: Examining the Effect of Intra-Arterial Therapy on Outcomes in IV tPA Ineligible Ischemic Stroke Patients

Abstract

Background: Recent randomized trials (RCTs) have failed to show benefit of intra-arterial therapy (IAT) compared with patients given IV tPA alone. Many patients, however, are ineligible for IV tPA, who were not included in IMS-3, MR-RESCUE or SYNTHESIS. We investigated potential treatment effects of IAT in patients with acute ischemic stroke ineligible for tPA. Methods: In a US multicenter retrospective cohort study, we identified 476 AIS IV tPA ineligible patients with large artery occlusions (LAO) from 01/08 to 06/13. Inclusion criteria was <6hrs from symptom onset for anterior circulation and <12hrs for posterior circulation. Patients were divided into two arms (IAT vs No IAT). Logistic regression with good and bad (discharge mRS 0-2 and 4-6 respectively) outcome was performed to compare the two arms. Univariate and multivariate analyses evaluated independent predictors of good outcome after IAT. Results: Table 1 shows baseline characteristics. Presentation >4.5 hrs (52%), high INR (11%) and recent procedure (10%) were the main reasons for IV tPA ineligibility. IAT patients had 4 times greater odds of good (OR 3.9, 95%CI 1.5-10, p=0.004) and significantly less odds of poor outcome (OR 0.3, 95%CI 0.17-0.55, p<0.0001) compared to those without IAT. Significance was maintained under nearly all conditions after adjustment was made for covariates (Table 2). The distribution of mRS scores demonstrated a shift towards better outcomes in IAT treated patients (Fig 1) in spite of higher death rates in this group. In univariate analysis, good ASPECTS (8-10), good reperfusion (TICI ≥2b) and time were independent predictors of good outcome after IAT. Start of IAT in the first 3hrs from onset was associated with 5 times the odds of a good outcome than later IAT initiation (5.3, 95%CI 1.99-14.6, p=0.001). Conclusion: IAT may improve clinical outcomes in patients with LAO who are IV tPA ineligible. Testing for IAT efficacy in this patient population will require RCTs to validate our findings.