Original title: Endovascular Therapy after Intravenous t-PA versus t-PA Alone for Stroke. Interventional Management of Stroke (IMS) III. Reference: Joseph P. Broderick et al. N Engl J Med 2013.DOI: 10.1056/NEJMoa1214300
Tissue plasminogen activator (t-PA; alteplase [Activase, Genentech, or Actilyse, Boehringer Ingelheim]) is the only reperfusion therapy proved useful for patients with acute ischemic stroke and its clinical efficacy depends critically on time.
Only a small number of patients meet the criteria to receive t-PA (<10%) mainly due to the short therapeutic window (<4.5 hs). Endovascular treatment can re-channel big arteries with high thrombotic charge more effectively than t-PA but requires time to organize the intervention team and sometimes to transfer patients from one center to another. T-Pa infusion followed by endovascular therapy combine, in theory, the advantages of both and this is why this randomized study was designed.
All patients received t-PA within 3 hrs after symptoms onset and presented a moderate to severe neurological deficit defined as a NIHSS score of ≥ 10 (National Institutes of Health Stroke Scale). The primary outcome measure modified Rankin score (it measures disability after stroke) of 2 or less at 90 days. This cut was chosen because it indicates the functional independence of patients. At total of 656 patients were randomized (434 to t-PA in addition to endovascular therapy and 222 to t-PA only) between 2006 and 2012.
The study was completed prematurely due to the absence of significant difference in primary end point between endovascular therapy combined with t-PA or t-PA alone (40.8% vs. 38.7%). As regards safety, there were no differences between the groups both in mortality, symptomatic intracerebral hemorrhage or intraparenquimatous hematoma. Automatic intracerebral hemorrhage was more frequent with endovascular therapy (p=0.01).
Conclusion
Endovascular treatment after t-PA compared with t-PA alone in patients undergoing acute stroke, showed similar safety and added no benefits.
Editorial Comment:
Initially, materials for endovascular treatment were scarce, but as new devices were approved, the study incorporated them with the pertinent amendments to protocol. The latter produced a mix of devises with different results in the group of endovascular therapy that difficults interpretation. It may have been ambitious to set clinical primary end points when, for instance, the TICI flow (similar to the TIMI flow for the coronary arteries) could have been proved superior with endovascular treatment.
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