Additional endovascular therapy in patients with acute ischemic stroke who are nonresponsive to intravenous tissue plasminogen activator: usefulness of magnetic resonance angiography-diffusion mismatch.

Background: In patients who are not responsive to intravenous tissue plasminogen activator (IV t-PA), the present study aimed to report recanalization rates, the incidence of hemorrhagic transformation (HT), and clinical outcomes of additional endovascular therapy (AET), and to investigate the usefulness of magnetic resonance angiography-diffusion mismatch (MDM) in a selection of patients eligible for AET.

Methods: Fifty-eight patients who received IV t-PA therapy because of intracranial major artery occlusion between April 2007 and November 2010 were divided into 2 groups: 18 patients in the AET group and 21 patients in the IV t-PA nonresponders group. The remaining 19 patients were responders to IV t-PA and therefore not eligible for this study. Recanalization rates, HT incidence, and 3-month outcomes were assessed, and the relationship between MDM and clinical outcome was examined.

Results: A 3-month modified Rankin Scale (mRS) score of 0 to 3 was seen more frequently in the AET group (72% in the AET group v 29% in the nonresponder group; P = .01). Serious outcomes (3-month mRS of 5-6) were seen significantly less often in the AET group (17%) than in the nonresponder group (57%; P = .019). There were no differences in the incidence of HT. In the AET group, reappraisal considering MDM revealed a significantly higher rate of a 3-month mRS of 0 to 3 in the MDM-positive group compared to the MDM-negative group (86% v 25%, respectively; P = .044). Serious outcomes were observed significantly less frequently in the MDM-positive group compared to the MDM-negative group (0% v 75%, respectively; P = .005).

Conclusions: AET for nonresponders to IV t-PA was safe, improved recanalization rates, and led to better prognoses. MDM was a very good predictor of improved prognosis in a selection of eligible patients for AET after IV t-PA.