Direct Intra-arterial thrombectomy in order to Revascularize AIS patients with large vessel occlusion Efficiently in Chinese Tertiary hospitals: A Multicenter randomized clinical Trial (DIRECT-MT)-Protocol.

RATIONALE

Intravenous thrombolysis combined with mechanical thrombectomy (MT) has been proven safe and clinical effective in patients with acute ischemic stroke of anterior circulation large vessel occlusion. However, despite reperfusion, a considerable proportion of patients do not recover. Incidence of symptomatic intracerebral hemorrhage was similar between patients treated with the combination of intravenous thrombolysis and MT, as compared to intravenous thrombolysis alone, suggesting that this complication should be attributed to pre-treatment with intravenous thrombolysis. Conversely, intravenous thrombolysis may be beneficial in patients with small clots occluding intracranial arteries with underlying intracranial atherosclerotic disease, not accessible for MT.

AIM

To assess whether direct MT is non-inferior compared to combined intravenous thrombolysis plus MT in patients with AIS due to an anterior circulation large vessel occlusion, and to assess treatment effect modification by presence of intracranial atherosclerotic disease.

SAMPLE SIZE

Aim to randomize 636 patients 1:1 to receive direct MT (intervention) or combined intravenous thrombolysis plus MT (control).

DESIGN

This is a multicenter, prospective, open label parallel group trial with blinded outcome assessment (PROBE design) assessing non-inferiority of direct MT compared to combined intravenous thrombolysis plus MT.

OUTCOMES

The primary outcome is the score on the modified Rankin Scale assessed blindly at 90 (±14) days. An common odds ratio, adjusted for the prognostic factors (age, NIHSS, collateral score), representing the shift on the 6-category mRS scale measured at three months, estimated with ordinal logistic regression, will be the primary effect parameter. Non-inferiority is established if the lower boundary of the 95% confidence interval does not cross 0.8.

DISCUSSION

DIRECT-MT could result in improved therapeutic efficiency and cost reduction in treatment of anterior circulation large vessel occlusion stroke.