A Randomized Trial of Intraarterial Treatment for Acute Ischemic Stroke (MR CLEAN Trial)

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BOTTOM LINE

• In patients with acute ischemic stroke from proximal intracranial occlusion of arterial circulation,intraarterial treatment (IAT) within 6 hours of stroke onset was safe and effective, leading to anincrease in functional recovery without greater mortality. .

MAJOR POINTS

• As a contrast to recent trials which showed no benefit to IAT, this study showed a clear, patient-centered outcome of improved functional status as a result of if IAT.

• NIH Stroke Scale after 5-7 days 2.9 points lower in the intervention group than the control group.

• No significant between group difference in mortality or other severe adverse events during the 90day follow up.

CRITICISM

• Unbalanced randomization, with more patients in the control group than the intervention group.

Addressed by stratification.

• Lower reperfusion rate than recent case series. May have resulted from heterogeneity of outcome

measures.

• 9% of patients in the intervention group experienced embolization to new vascular territories.

• Patients aware of their treatment group assignments.

Quick Summary

RANDOMIZED CONTROL TRIAL

• 500 patients at 16 medical centers in the Netherlands with proximal arterial occlusion in the anterior cerebral circulation that was confirmed on vessel imaging and that could be treated intraarterially within 6 hours after symptom onset, from December 2010 to May 2014.

INCLUSION CRITERIA

• Patients 18 years of age or older.

• Occlusion of the distal intracranial carotid artery, middle cerebral artery (M1 or M2), or anterior cerebral artery (A1 or A2).

• Verified by CT, CTA, MRA, or DSA.

EXCLUSION CRITERIA

• Cerebral infarction in distribution of the relevant occluded artery in the previous 6 weeks.

• Arterial blood pressure >185/110.

• Blood glucose <2.7 or >22.2 mmol/L.

Study design

• In patients with acute ischemic stroke from proximal intracranial arterial occlusion, intraarterial treatment will effectively revascularize these territories. Prior to this study, however, there has not been a demonstration of a functional benefit to the patient from this revascularization.

Purpose

• Actual intraarterial therapy (with or without mechanical thrombectomy) was performed in 196 of 233 patients in the intervention group (84.1%). Mechanical treatment was performed in 195 of the 233 patients (83.7).

Intervention

Outcome

• Shift in the distribution of primary outcome scores in favor of the intervention, consistent across all categories of the modified Rankin scale, except for death.

Credits

SUMMARY BY:

Jeffrey Barrett Donaldson, M.S., MS4College of MedicineSUNY Upstate Medical University

FULL CITATION:

Berkhemer, Olvert A., et al. "A randomized trial of intraarterial treatment for acute ischemic stroke." New England Journal of Medicine 372.1 (2015): 11-20.

Fransen, Puck SS, et al. "MR CLEAN, a multicenter randomized clinical trial of endovascular treatment for acute ischemic stroke in the Netherlands: study protocol for a randomized controlled trial." Trials 15.1 (2014): 343.

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