Benefit of Endovascular Thrombectomy in Patients With Large Ischemic Cores

Endovascular thrombectomy (EVT) may have therapeutic benefits for patients with large infarcts, especially if they are treated early and have a large core volume, according to a prespecified secondary analysis of the Optimizing Patient’s Selection for Endovascular Treatment in Acute Ischemic Stroke (SELECT) trial published in JAMA Neurology.

Previous studies have shown that in select patients, EVT is safe and efficacious up to 24 hours after ischemic stroke onset secondary to large-vessel occlusion in the anterior circulation. These studies, however, focused on patients with small ischemic cores or minimal ischemic changes on imaging. The goal of this study was to assess the added value of EVT to medical management in patients with large ischemic cores.

The SELECT trial (ClinicalTrials.gov Identifier: NCT02446587) enrolled patients with ischemic stroke caused by large-vessel occlusion treated with either EVT plus medical management or medical management alone. The study, conducted in 9 US comprehensive stroke centers, enrolled patients between January 2016 and February 2018 with a follow-up period of 90 days. This prespecified analysis included 105 patients with substantial ischemic changes on computed tomography (CT) (Alberta Stroke Program Early CT Score [ASPECTS], 0-5) or computed tomographic perfusion (CTP) imaging (ischemic volume ≥50 cm³) at the time of presentation.

Primary outcome was the 90-day functional outcome per modified Rankin Scale (mRS) score. Safety outcomes included symptomatic intracerebral hemorrhage, neurologic worsening,  and mortality at 90 days.

Of the 105 patients (median age 66 years, 43% female) included in this analysis, 62 patients received EVT plus medical management and 43 patients had medical management only. Large cores on both CT and CTP were evident in 40 patients, including 14 patients in the EVT plus medical management group and 26 patients in the medical management alone group.

Functional independence (mRS score of 0 to 2) was achieved in 31% (19 of 62) of patients who received EVT vs 14% (6 of 43) who received medical management only (odds ratio [OR] 3.27; 95% CI, 1.11-9.62; P =.03). Furthermore, there was a shift toward better outcomes across the mRS categories with EVT (OR 2.12; 95% CI, 1.05-4.31; P =.04), smaller final infarct volume (median 97 mL vs 190 mL; P <.001), and less infarct growth (44 mL vs 98 mL; P =.006).

Deaths, neurologic worsening, and symptomatic intracerebral hemorrhage were observed in similar proportions across both groups.

Patients with ischemic core volumes of 50 to 100 cm³ had good outcome rates (28% [8 of 29]), whereas no patient (0 of 10) with a core volume >100 cm³ had functional independence at 90 days. The likelihood of functional independence declined by 42% with each 10-cm³ increase in stroke volume on CTP (adjusted OR 0.58; 95% CI, 0.39-0.87; P =.007).  In a similar fashion, the odds of a good outcome declined by 40% with each hour delay and there was a very low (<10%) probability of achieving functional independence when EVT occurred more than 12 hours after stroke onset.

The study had several limitations, according to the researchers. These included the retrospective nature of the analyses, lack of randomization, differences between groups in core lesion size, and small sample of patients with an ischemic core size >100 cm³.

“In patients with large cores on CT or CTP images, EVT resulted in reasonable rates of functional independence with acceptable safety,” concluded the researchers. They went on to note, “The potential benefit of EVT is likely less and the risks of hemorrhage greater in patients who present late or have very large core sizes (>100 mL).”

Disclosure: This clinical trial was supported by Stryker Neurovascular. Please see the original reference for a full list of authors’ disclosures.

Reference

Sarraj A, Hassan AE, Savitz S, et al. Outcomes of endovascular thrombectomy vs medical management alone in patients with large ischemic cores: a secondary analysis of the optimizing patient’s selection for endovascular treatment in acute ischemic stroke (SELECT) study [published online July 29, 2019]. JAMA Neurol.  doi:10.1001/jamaneurol.2019.2109