Endovascular therapy reduced disability and death in patients with DWI-ASPECTS values of 6 or less, indicative of large lesion volumes.
Achieving successful reperfusion with mechanical thrombectomy seems to improve outcomes in patients with acute ischemic stroke and large infarct volumes, who were not well represented in recent clinical trials.
Among patients with a diffusion-weighted imaging (DWI)-ASPECTS value of 6 or less, successful reperfusion (TICI score 2b/3) was associated with a higher rate of early neurological improvement and reduced rates of disability and death at 90 days, Jean-Philippe Desilles, MD (Fondation Rothschild, Paris, France), and colleagues report in a study recently published online in Stroke.
“Our findings suggest that large DWI lesion volumes should not preclude patients from reperfusion therapies, including IV tPA and [mechanical thrombectomy],” they write. “Further randomized data are needed to confirm this conclusion.”
No Difference in Hemorrhagic Complications
Worse values on ASPECTS, which provides information about early ischemic signs seen on an acute head CT, have been associated with poorer outcomes in patients treated with IV thrombolytics for acute stroke. Combining magnetic resonance DWI with that assessment, DWI-ASPECTS has been shown to be useful for characterizing brain infarction volume, with a threshold of 6 or less identified as the best predictor of a DWI lesion volume of 100 mL or more.
For the current study, Desilles et al looked at the impact of mechanical thrombectomy with either a stent retriever or the direct aspiration first pass technique in 218 patients treated between January 2012 and August 2015 at two centers. All had documented internal carotid artery or middle cerebral artery occlusion and a pretreatment DWI-ASPECTS of 6 or less (median 5).
The intervention resulted in successful reperfusion in 66.5% of patients. Those patients had higher rates of early neurological improvement (45.7% vs 18.1%; P < 0.001) and favorable functional outcome, defined by an mRS score of 2 or less at 90 days (38.7% vs 17.4%; P = 0.002), as well as a lower rate of mortality at 90 days (22.6% vs 39.1%; P = 0.013). Those differences held up after multivariate adjustment.
Hemorrhagic complications, including symptomatic intracranial hemorrhage, did not differ based on the whether reperfusion was achieved.
The authors note that most of the recent trials of endovascular therapy for acute stroke did not show a survival benefit. “The mortality reduction observed in our study may be explained by the fact that the target population (ie, with the largest acute ischemic stroke volumes) has certainly the highest mortality rate with conventional treatment,” they write. “These findings suggest that successful reperfusion may prevent DWI lesion growth, avoiding malignant infarction evolution responsible for mortality.”
Questionable Effects in Subgroup With Lowest DWI-ASPECTS
The researchers further divided patients into three groups based on DWI-ASPECTS: 0-4, 5, and 6. Successful reperfusion remained associated with benefits in patients with scores of 5 or 6, although not all relationships reached statistical significance.
In patients with DWI-ASPECTS 0 to 4, however, rates of early neurological improvement and favorable outcome were low and did not indicate a significant benefit of mechanical thrombectomy. Mortality was high and did not differ based on reperfusion status at the end of the procedure.
“Still, there was a trend toward better early neurological outcome (23.1% vs 9.5%), lower mortality rate at 3 months (45.7% vs 57.1%), and lower [parenchymal hematoma] rate (23.9% versus 45.5%) in the reperfused DWI-ASPECTS 0 to 4 subgroup patients compared with nonreperfused patients,” the authors note. “Further data from randomized studies are needed to clarify the potential benefit of [mechanical thrombectomy] in this subgroup of patients.”
Sources:
Desilles J-P, Consoli A, Redjem H, et al. Successful reperfusion with mechanical thrombectomy is associated with reduced disability and mortality in patients with pretreatment diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score ≤ 6. Stroke. 2017;Epub ahead of print.
Disclosures:
Desilles reports no relevant conflicts of interest.
