Combined Intravenous and Intra-Arterial Recanalization for Acute Ischemic Stroke: The Interventional Management of Stroke Study

Subjects ages 18 to 80 with an NIH Stroke Scale (NIHSS) > or =10 at baseline had IV recombinant tissue plasminogen activator (rt-PA) started (0.6 mg/kg, 60 mg maximum over 30 minutes) within 3 hours of onset. Additional rt-PA was then administered via microcatheter at the site of the thrombus up to a total dose of 22 mg over 2 hours of infusion or until thrombolysis. Primary comparisons were with similar subsets of placebo and rt-PA-treated subjects from the NINDS rt-PA Stroke Trial.

The 80 subjects had a median baseline NIHSS score of 18. The median time to initiation of IV rt-PA was 140 minutes as compared with 108 minutes for placebo and 90 minutes for rt-PA-treated subjects in the NINDS rt-PA Stroke Trial. The 3-month mortality in Interventional Management Study (IMS) subjects (16%) was numerically lower but not statistically different than the mortality of placebo (24%) and rt-PA-treated subjects (21%) in the NINDS rt-PA Stroke Trial. The rate of symptomatic intracerebral hemorrhage (6.3%) in IMS subjects was similar to that of rt-PA-treated subjects (6.6%) but higher than the rate in placebo-treated subjects (1.0%, P=0.018) in the NINDS rt-PA Stroke Trial. IMS subjects had a significantly better outcome at 3 months than NINDS placebo-treated subjects for all outcome measures (odds ratios > or =2).