ISC.15: Stent thrombectomy pulls ahead of alteplase alone in ischemic stroke

Providing more proof that time is brain, a randomized trial found that promptly performing thrombectomy with a stent retriever in carefully selected ischemic stroke patients led to better outcomes than did alteplase treatment alone.

Representing the EXTEND-IA (Extending the Time for Thrombolysis in Emergency Neurological Deficits — Intra-Arterial) trial group, Bruce Campbell, MBBS, PhD, a neurologist at the Royal Melbourne Hospital in Parkville, Australia, presented the findings Feb. 11 at the American Stroke Association’s 2015 International Stroke Conference (ISC) in Nashville, Tenn. They published their results simultaneously online in the New England Journal of Medicine.

EXTEND-IA is an investigator-initiated study designed to evaluate the use of a strategy that combined advanced imaging, current technology and early treatment in patients with ischemic stroke. To be eligible, patients needed to meet a number of criteria: receive intravenous alteplase within 4.5 hours of stroke onset; have anterior circulation ischemic stroke; have a major artery occlusion (internal carotid artery or the first or second segment of the middle cerebral artery) detected by CT angiography; and salvageable brain tissue as seen on CT perfusion imaging.

All patients received alteplase initially and then were randomized to endovascular therapy with the Solitaire Flow Restoration retrievable stent (Covidien) or continued alteplase therapy. The researchers intended to enroll 100 patients but terminated the trial early on Oct. 31, 2014, at 70 patients because of efficacy.  

Mean reperfusion at 24 hours totaled 100 percent with endovascular therapy vs. 37 percent with alteplase alone. Early neurological improvement at three days occurred in 80 percent of the endovascular therapy group vs. 37 percent of the alteplase group. The endovascular therapy group also had improved functional outcomes and were more likely to be independent at 90 days compared with the alteplase group.

“The results of this trial were unequivocal, despite the small sample size,” they wrote.

Two patients in the alteplase group experienced fatal intracerebral bleeding, which didn't occur in the endovascular group. But two patients in the endovascular group developed parenchymal hematoma. Campbell et al reported no significant difference in death between the groups.

One quarter of clinically eligible patients were excluded based on perfusion-imaging results. They proposed that the use of CT perfusion imaging helped to rule out patients who were less likely to benefit from the endovascular approach.

Unlike the MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands) trial—whose positive results prompted the examination of their data and decision to end enrollment early—they did not pause to assess the response to alteplase. That allowed for faster initiation of endovascular therapy, “which also may have contributed to the substantially higher proportion of patients with independent functional outcomes observed in our study,” they wrote.