EXTEND-IA: Early thrombectomy with stent retriever linked to better outcomes

NASHVILLE, Tenn. — In patients with ischemic stroke with a proximal cerebral arterial occlusion and salvageable tissue, early thrombectomy with a stent retriever was associated with improved outcomes compared with alteplase alone.

Previous trials of endovascular therapy for ischemic stroke have produced inconsistent results, so researchers for a new study examined whether advanced imaging selection, new devices and earlier intervention would improve outcomes.

Bruce C.V. Campbell, MD, and colleagues randomly assigned patients receiving alteplase 0.9 mg/kg of body weight less than 4.5 hours after ischemic stroke to endovascular thrombectomy with a stent retriever (Solitaire FR, Covidien) or continued alteplase alone. All patients had occlusion in the internal carotid or middle cerebral artery, as well as ischemic core less than 70 mL based on CT perfusion imaging.

Bruce C.V. Campbell

Campbell told Cardiology Today that the device “is a stent which is deployed via angiogram within the thrombus that is blocking the artery in the brain and then withdrawn under negative pressure suction with the aim of retrieving the thrombus.”

The co-primary outcomes were reperfusion at 24 hours and early neurologic improvement, defined as a reduction of eight points or more on the NIH stroke scale or a score of 0 or 1 at 3 days. A secondary outcome was functional score on the modified Rankin scale at 90 days.

The trial was stopped early because of efficacy after 70 patients — 35 in each group — of a planned 100 had undergone randomization.

According to results presented, a median of 100% of patients in the stent-retriever group had undergone reperfusion at 24 hours vs. a median of 37% in the alteplase-only group (P < .001). Campbell told Cardiology Today that the proportion of patients with reperfusion of 90% or greater at 24 hours were 89% in the stent-retriever group and 34% in the alteplase-only group. They also found that early neurologic improvement occurred in 80% of the stent-retriever group vs. 37% in the alteplase-only group (P = .002).

Functional independence at 90 days, defined as a score of 0 to 2 on the modified Rankin scale, occurred in 71% of the stent-retriever group vs. 40% in the alteplase-only group (P = .01).

The researchers found no significant differences between the groups in the rate of death or symptomatic intracerebral hemorrhage.

EXTEND-IA, as well as the ESCAPE and SWIFT PRIME trials, “will truly revolutionize the way we treat large vessel occlusion stroke and transform the outcomes for this most severely affected group of patients,” Campbell, from the department of neurology at Royal Melbourne Hospital, Parkville, Victoria, Australia, said in an interview.

“The Dutch MR CLEAN trial was the first to show positive benefit of endovascular therapy, but these three new trials provide the confirmatory evidence that the stroke community have been waiting for and show an even more powerful treatment effect. Stent thrombectomy is the new standard of care for these patients and we need to rearrange our systems of care to implement this.” – by Erik Swain

References:

Campbell BCV. Plenary Session I: LB2. Presented at: International Stroke Conference; Feb. 11-13, 2015; Nashville, Tenn.

Campbell BCV, et al. N Engl J. Med. 2015;doi:10.1056/NEJMoa1414792.

Disclosure: The study was supported by the Australian National Health and Medical Research Council and other noncommercial entities. Covidien supplied the devices for free and an unrestricted grant for trial infrastructure, but had no role in the design, conduct or analysis of the study. Campbell reports no relevant financial disclosures.