NEW YORK (Reuters Health) – Endovascular therapy (EVT) may be effective for acute ischemic stroke caused by occlusion of the middle cerebral artery M2 segment, suggests a multicenter retrospective study.

“Now that EVT is the standard of care for patients with large vessel occlusions, efforts should focus on expanding the treatment indications, as in the subgroup we studied, refining patients selection methods for endovascular therapy, which we are evaluating in the SELECT trial, and reorganizing systems of care so more patients have access to this highly effective treatment,” Dr. Amrou Sarraj from McGovern Medical School at The University of Texas Health Science Center at Houston told Reuters Health by email.

At least five published randomized clinical trials have found EVT to be superior to best medical management for patients with acute ischemic strokes with large vessel occlusion in the anterior circulation, but most of these involved the proximal (M1) segment of the middle cerebral artery (MCA).

Dr. Sarraj and colleagues used pooled data from 10 participating academic U.S. stroke centers to evaluate the safety and treatment effect of EVT compared with best medical management in 522 patients with acute ischemic stroke with large vessel occlusions in the M2 segment of the anterior circulation.

More patients treated with EVT (62.8%) than with best medical management (35.4%) had good 90-day clinical outcomes (odds ratio, 3.1; p<0.001), the researchers report in JAMA Neurology, online September 12.

Younger age, lower admission NIH Stroke Scale score, higher Alberta Stroke Program Early Computed Tomographic Score (ASPECTS), shorter time from last known normal state to reperfusion, and successful reperfusion were independently associated with good outcomes in the EVT group.

The EVT group had higher rates of symptomatic intracranial hemorrhage (5.6% vs. 2.1%) and lower rates of asymptomatic intracranial hemorrhage (5.2% vs. 7.3%), but neither of these differences achieved statistical significance.

“Our study results come in agreement with prior data showing that younger patients (younger than 80) with small core infarct (less early ischemic changes on CT) upon arrival with moderate to severe strokes who get treated within the 5 to 6 hours’ mark would benefit best from the intervention,” Dr. Sarraj said. “Those patients were shown over and over again to have the greatest benefit from endovascular therapy.”

“The main message we hope this study will send is that in patients with disabling strokes due to more distal occlusions, specifically M2 occlusions, endovascular therapy is effective, probably superior to best medical management including IV thrombolytics with a treatment effect similar to those with proximal occlusions in which EVT is the standard of care,” he said.