DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo - DAWN
Contribution To Literature:
The DAWN trial showed that, among patients with acute ischemic stroke presenting 6-24 hours after symptom onset due to proximal large arterial occlusion, and with evidence of a mismatch between infarct volume on imaging and severity of clinical deficits, endovascular thrombectomy along with standard of care was superior to routine standard of care for outcomes of disability and functional independence at 90 days.
The goal of the trial was to compare the role of endovascular thrombectomy plus standard medical care compared with standard medical care alone for the treatment of patients with acute stroke 6-24 hours earlier, and who had a mismatch between clinical deficit and infarct volume.
Patients with acute ischemic stroke presenting 6-24 hours after symptom onset and evidence of mismatch were randomized to endovascular thrombectomy with standard care (n = 107) or standard care alone (control; n = 99). Thrombectomy was performed with the use of the Trevo device (Stryker Neurovascular), a retrievable self-expanding stent that is used to remove occlusive thrombi and restore blood flow. Rescue reperfusion therapy with other devices or pharmacologic agents was not permitted.
- Total number of enrollees: 206
- Duration of follow-up: 90 days
- Mean patient age: 70 years; age ≥80 years = 26%
- Percentage female: 45%
- Percentage with diabetes: 28%
- Age ≥18 years
- Interval between the time that the patient was last known to be well and randomization of 6-24 hours
- Pre-stroke score of 0 or 1 on the modified Rankin scale
- No evidence of intracranial hemorrhage on computed tomography (CT) or magnetic resonance imaging (MRI)
- No evidence of an infarct involving more than one third of the territory of the middle cerebral artery on CT or MRI at baseline
- Occlusion of the intracranial internal carotid artery, the first segment of the middle cerebral artery, or both on CT angiography or MR angiography
- Mismatch between the severity of the clinical deficit and the infarct volume, which was defined according to the following criteria:
- Group A: ≥80 years of age, had a National Institutes of Health Stroke Scale (NIHSS) score of ≥10, and had an infarct volume of <21 ml
- Group B: <80 years of age, had a NIHSS score of ≥10, and had an infarct volume of <31 ml
- Group C: <80 years of age, had a NIHSS score of ≥20, and had an infarct volume of 31 to <51 ml.
Other salient features/characteristics:
- Median NIHSS score: 17
- Treatment with intravenous tissue plasminogen activator: 8%
- Median stroke volume: 8.2 ml
- Stroke onset type: on awakening: 55%, unwitnessed stroke: 32%
- Occlusion site: M1: 78%
The study stopped early due to efficacy. The primary outcome, score on utility-weighted modified Rankin scale at 90 days between the thrombectomy group vs. control, was 5.5 vs. 3.4, posterior probability of superiority > 0.999. Functional independence at 90 days was 49% vs. 13%, post probability > 0.999.
Secondary outcomes for thrombectomy vs. control:
- Recanalization at 24 hours: 77% vs. 39%, p < 0.001
- Change from baseline in infarct volume at 24 hours: 1 vs. 13 ml, p = 0.003
- Median infarct volume at 24 hours: 8 vs. 22 ml, p < 0.001
- Stroke-related death at 90 days: 16% vs. 18%
- Symptomatic intracranial hemorrhage at 24 hours: 6% vs. 3%
Among patients with acute ischemic stroke (with a small to medium stroke volume) presenting 6-24 hours after symptom onset due to proximal large arterial occlusion, and with evidence of a mismatch between infarct volume on imaging and severity of clinical deficits, endovascular thrombectomy along with standard of care was superior to routine standard of care for outcomes of disability and functional independence at 90 days.
This is a very important trial and suggests that endovascular treatment may be beneficial if salvageable/ischemic brain tissue (i.e., noninfarcted) can be demonstrated even outside the typical 6-hour window. Further studies are needed to establish the prevalence of patients who would be eligible for thrombectomy among the entire population of patients with ischemic stroke. The need for a qualifying perfusion CT or MRI, as required in this trial, may limit this approach to specialized/select stroke sites.
Nogueira RG, Jadhav AP, Haussen DC, et al., on behalf of the DAWN Trial Investigators. Thrombectomy 6 to 24 Hours After Stroke With a Mismatch Between Deficit and Infarct. N Engl J Med 2018;378:11-21.
Perspective: Alberts MJ, Ollenschleger MD, Nouh A. DAWN of a New Era for Stroke Treatment: Implications of the DAWN Study for Acute Stroke Care and Stroke Systems of Care. Circulation 2018;Jan 18:[Epub ahead of print].
Clinical Topics: Cardiac Surgery, Geriatric Cardiology, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Aortic Surgery, Interventions and Imaging, Angiography, Magnetic Resonance Imaging, Nuclear Imaging
Keywords: Angiography, Diagnostic Imaging, Endovascular Procedures, Geriatrics, Intracranial Hemorrhages, Magnetic Resonance Imaging, Reperfusion, Standard of Care, Stents, Stroke, Stroke Volume, Thrombectomy, Vascular Diseases, Tomography
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