Although the incidence of symptomatic intracranial hemorrhage was low, 18% of the patients in the endovascular thrombectomy group had complications associated with the procedure.
Recently published in The New England Journal of Medicine, new findings from the SELECT2 trial (NCT03876457), a phase 3 international, randomized, open-label clinical trial, showed endovascular thrombectomy (EVT) resulted in better functional outcomes than medical care among patients with large ischemic strokes 24 hours after onset.1 These results provide evidence of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes, which has been carried out in limited populations to date.
In favor of EVT, the generalized odds ratio for a shift in the distribution of modified Rankin scale (mRS) scores toward better outcomes was 1.51 (95% CI, 1.20-1.89; P <.001). Notably, a total of 20% of the patients in the EVT group and 7% in the medical-care group had functional independence (RR, 2.97; 95% CI, 1.60-5.51).
These findings were also presented as an oral presentation in the clinical trials plenary session at the 2023 American Academy of Neurology (AAN) Annual Meeting, April 22-27, in Boston, Massachusetts, by lead author Amrou Sarraj, MD, director of the Cerebrovascular Center and Comprehensive Stroke Center at University Hospitals Cleveland Medical Center. The session covered the latest clinical trial results that impact the landscape of patient care in all the neurology subspecialities.2
Between September 2019 and September 2022, at the time the trial was stopped, 958 patients had been screened, and among those, 352 were eligible and enrolled. The trial included patients with stroke because of occlusion of the internal carotid artery or the first segment of the middle cerebral artery, and assessed EVT in the time span of 24 hours after onset. The patients enrolled had a large ischemic-core volume, defined by the Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0- 10, with lower scores indicating larger infarction) or at least 50 mL of a core volume on computed tomography perfusion or diffusion-weighted MRI.
Patients were assigned on a 1:1 ratio to either the EVT plus medical care group (n = 178) or the medical care alone group (n = 174). The mRS score at 90 days (range, 0-6, with higher scores indicating greater disability) was the primary outcome, and functional independence was the secondary outcome.
Among both groups, mortality was similar. Arterial access-site complications occurred in 5 patients, dissection in 10 patients, cerebral-vessel perforation in 7 patients, and transient vasospasm in 11 patients, all of whom were in the EVT group. One patient in the EVT group and 2 patients in the medical-care group experienced symptomatic intracranial hemorrhage.
Limitations of the trial include its early termination and the smaller than anticipated sample size. Although treatment was open label, the outcome assessment was conducted by assessors who were unaware of trial-group assignments. In addition, some patients enrolled had lower ischemic-core volumes than intended for enrollment and only approximately 20% of patients received intravenous thrombolytic agents before randomization.
Previous coverage of SELECT2 identified no safety concerns during a review of 90-day outcomes for the first 200 included participants.3 Findings from that analysis were presented at the 2022 International Stroke Conference (ISC) February 9-11, in New Orleans, Louisiana, by Sarraj. In the analysis, 200 patients were enrolled in the phase 3 study, 100 patients randomized received EVT and 100 were randomized to medical management (MM).
In the data presented at ISC 2023, participants in the EVT group had a median age of 66.5 years (IQR, 58.5-75) and those in the MM group had a median age of 67.5 (IQR, 59-76). Presentation National Institutes of Health Stroke Scale (NIHSS) scores were similar, averaging 19 (IQR, 15-23) for the EVT group and 19 (IQR, 15-23) in the MM group, as was time from stroke onset to randomization, averaging 9.3 hours (IQR, 5.0-15.25) for the EVT group and 9.9 hours (IQR, 5.95-15.9) for the MM group, and physician read CV Alberta Stroke Program Early CT Scores (ASPECTS), at 4 (IQR, 4-5) for the EVT group and 4 (IQR, 4-5) for the MM group. Overall, 176 patients had NCCT ASPECTS between 3-5, with a median ischemic core of 72 mL (IQR, 38.5-108.5). A total of 145 patients had an ischemic core of 50 mL, with a median ischemic core of 94 (IQR, 72-138).
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