May 6, 2020
DIRECT-MT Studies Endovascular Thrombectomy With or Without Intravenous Alteplase in Acute Stroke
May 6, 2020—Investigators in the DIRECT-MT study of Chinese patients with acute ischemic stroke from large-vessel occlusion concluded that endovascular thrombectomy alone was noninferior with regard to functional outcome, within a 20% margin of confidence, compared with endovascular thrombectomy preceded by intravenous alteplase administered within 4.5 hours after symptom onset. Pengfei Yang, MD, et al published the study findings online ahead of print in The New England Journal of Medicine (NEJM).
The DIRECT-MT trial was conducted at 41 academic tertiary care centers in China to evaluate the benefit and risk of administering intravenous alteplase before endovascular thrombectomy in acute ischemic stroke.
As summarized in NEJM, patients with acute ischemic stroke from large-vessel occlusion in the anterior circulation were randomly assigned in a 1:1 ratio to undergo endovascular thrombectomy alone (thrombectomy-alone group) or endovascular thrombectomy preceded by intravenous alteplase, at a dose of 0.9 mg per kilogram of body weight, administered within 4.5 hours after symptom onset (combination-therapy group).
The primary analysis for noninferiority assessed the between-group difference in the distribution of the modified Rankin scale scores (range, 0 [no symptoms] to 6 [death]) at 90 days on the basis of a lower boundary of the 95% confidence interval (CI) of the adjusted common odds ratio ≥ 0.8. Additionally, the investigators assessed various secondary outcomes, including death and reperfusion of the ischemic area.
The study screened 1,586 patients and enrolled 656 patients, assigning them to the thrombectomy-alone group (n = 327) or the combination-therapy group (n = 329).
The investigators found that endovascular thrombectomy alone was noninferior to combined intravenous alteplase and endovascular thrombectomy with regard to the primary outcome (adjusted common odds ratio, 1.07; 95% CI, 0.81–1.40; P = .04 for noninferiority) but was associated with lower percentages of patients with successful reperfusion before thrombectomy (2.4% vs 7%) and overall successful reperfusion (79.4% vs 84.5%). Mortality at 90 days was 17.7% in the thrombectomy-alone group and 18.8% in the combination-therapy group, reported the DIRECT-MT investigators in NEJM.