This article is more than 5 years old. Information may no longer be current.
Thrombectomy safe, effective up to 24 hours after stroke
Compared with standard care, endovascular thrombectomy reduced disability in patients who had a stroke between 6 and 24 hours earlier and had a mismatch between clinical deficit and infarct, according to data from the randomized, multicenter, international DAWN trial.
Although previous data indicate that the clinical benefit of thrombectomy may be weakened if performed more than 6 hours after acute stroke, other study results suggest that patients with a clinical deficit that is disproportionately severe relative to the infarct volume may benefit from late thrombectomy, according to the researchers.
From 2014 to 2017, researchers randomly assigned 107 patients to thrombectomy with a retrievable self-expanding stent (Trevo, Stryker Neurovascular) plus standard medical care and 99 patients to standard medical care alone. Disability was evaluated using the utility-weighted modified Rankin scale, with a higher score indicating less symptoms or disability; rate of functional independence was evaluated using the modified Rankin scale, with higher scores indicating more severe disability, at 90 days.
All patients had occlusion of the intracranial internal carotid artery or proximal middle cerebral artery, were last known to be well between 6 and 24 hours earlier and had a mismatch between severity of the clinical deficit and the infarct volume. Mismatch criteria were defined according to age — younger or older than 80 years — and NIH Stroke Scale scores.
At 90 days, disability outcomes were significantly better with thrombectomy. The mean utility-weighted modified Rankin scale score was 5.5 in the thrombectomy group compared with 3.4 in the control group. Additionally, when compared with results from the control group, for every two people treated with thrombectomy, one additional patient had a better modified Rankin scale score for disability at 90 days.
Similarly, more patients in the thrombectomy group, as compared with the control group, achieved functional independence, as indicated by a modified Rankin scale score of 0 to 2 (49% vs. 13%). For every 2.8 patients treated with thrombectomy, one additional patient had functional independence at 90 days, according to the data.
Between the thrombectomy and control groups, the rates of symptomatic intracranial hemorrhage (6% vs. 3%; P = .5) and 90-day mortality (19% vs. 18%; P = 1) were not significantly different. The rate of neurologic deterioration, however, was lower with thrombectomy vs. standard care (14% vs. 26%; P = .04).
Trial enrollment was halted at 31 months due to the results of an interim analysis showing that the predictive probability of superiority of thrombectomy was at least 95% for the first primary endpoint of mean score for disability.
The researchers concluded that thrombectomy may be beneficial up to 24 hours after acute stroke in this patient population.
These data were previously reported by Cardiology Today before publication in The New England Journal of Medicine. – by Melissa Foster
Disclosures: This study was supported by Stryker Neurovascular. Please see the study for a full list of the authors’ relevant financial disclosures.