Late-Window Thrombectomy Shows Benefit for Transferred Patients with Ischemic Stroke

Amrou Sarraj, MD, an associate professor, director of the Vascular Neurology Fellowship at the University of Texas McGovern Medical School, and chief of the General Neurology Service at Memorial Hermann Hospital

Amrou Sarraj, MD

A subanalysis of the DEFUSE 3 trial has suggested that transferring patients who have had an ischemic stroke for late-window endovascular thrombectomy (EVT) may be associated with substantial clinical benefits.¹

The 90-day modified Rankin Scale score shift did not differ between the group that presented and was treated directly (n = 61; odds ratio [OR], 2.9; 95% CI, 1.2 to 7.2; P = .01) and the group that was transferred (n = 121; OR, 2.6; 95% CI, 1.3 to 4.8; P = .009). As well, the overall functional independence rate, defined as a Rankin Scale score of 0-2, in those treated with thrombectomy (direct, n = 34; transfer, n = 58) did not differ, nor did the treatment effect (direct OR, 2.0; 95% CI, 0.9 to 4.4; P = .07; transfer OR, 3.1; 95% CI, 1.6 to 6.1; P <.001).

“In late-window patients selected by computed tomography perfusion and/or magnetic resonance diffuse-weighted imaging and perfusion images with penumbral mismatch criteria at arrival, EVT outcomes were similar between those presenting directly to EVT-capable hospitals and those who were transferred,” wrote the authors, led by Amrou Sarraj, MD, an associate professor, director of the Vascular Neurology Fellowship at the University of Texas McGovern Medical School, and chief of the General Neurology Service at Memorial Hermann Hospital.

They concluded that “the results have health care implications indicating that transferring patients for late-window thrombectomy is associated with substantial clinical benefits and should be strongly encouraged.”

The DEFUSE 3 trial (NCT02586415) was a prospective, randomized, multicenter, blinded-end point trial included 182 patients with stroke with a large-vessel anterior circulation occlusion and initial infarct volume of less than 70 mL, mismatch ratio of at least 1.8, and mismatch volume of at least 15 mL, who were treated within 6 to 16 hours from the last known well. Of the 121 patients transferred, 58 received EVT while 63 received standard medical therapy. Likewise, of the 61 who presented directly, 34 were administered EVT while 27 received medical management.

With regard to imaging outcomes, patients who received EVT experienced lower 24-hour median infarct volume and 24-hour lesion infarct growth compared to medical therapy, regardless of presentation status. Although, these differences were not statistically significant. A pair of imaging outcomes did reach significance, though: reperfusion of >90% of the lesion at 24 hours and complete recanalization on computed tomography angiography or magnetic resonance angiography.

For the direct group, 76% (n = 22) of those receiving EVT experienced reperfusion of >90% compared to 9% (n = 2) of those receiving medical management (P <.001). Likewise, complete recanalization was achieved by 74% (n = 23) compared to 10% (n = 2), respectively (P <.001).

In the transfer cohort, 80% (n = 37) of those administered EVT experienced reperfusion of >90% compared to 22% (n = 10) in the medical management group (P <.001). Complete recanalization was achieved by 81% (n = 42) compared to 21% (n = 12), respectively (P <.001).

As for safety outcomes, the rates of death within 90 days were lower for patients receiving EVT notwithstanding whether they were transferred or presented directly to the study site but did not achieve statistical significance. The incidence of neurologic deterioration, symptomatic intracranial hemorrhage, and parenchymal hematoma type 2 were similar between the groups for both patients receiving EVT and patients receiving standard medical treatment.

“In late-window patients selected by penumbral mismatch criteria, both the favorable outcome rate and treatment effect did not decline in transfer patients,” the investigators concluded.

REFERENCE

1. Sarraj A, Mlynash M, Savitz SI, et al. Outcomes of thrombectomy in transferred patients with ischemic stroke in the late window: a subanalysis from the DEFUSE 3 trial. JAMA Neurol. Published online February 7, 2019. doi:10.1001/jamaneurol.2019.0118.