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Large-Vessel Stroke May Respond Best to Endovascular Therapy


 

AT THE ANNUAL MEETING OF THE SOCIETY OF NEUROINTERVENTIONAL SURGERY

SAN DIEGO – Patients who presented with acute ischemic stroke secondary to a large-vessel occlusion in the anterior circulation were nearly four times more likely to have a favorable outcome at 90 days if they underwent endovascular therapy than if they underwent intravenous rt-PA therapy in a single-center study.

"Large-vessel occlusions cause almost half of acute ischemic strokes and portend a poor prognosis if untreated," Dr. Ansaar T. Rai said at the annual meeting of the Society of Neurointerventional Surgery. "There are limited data comparing IV rt-PA [recombinant tissue-type plasminogen activator] and endovascular therapy outcomes for large-vessel occlusions. We need evidence to define the target population for endovascular therapy. We need to design meaningful trials around this target population and provide reasonable outcome expectations and information to patients presenting with acute ischemic stroke."

Dr. Ansaar T. Rai

Dr. Rai, an interventional neuroradiologist with West Virginia University, Morgantown, presented findings from a single-center, retrospective study of 223 patients with an intracranial vascular occlusion in the anterior circulation on baseline CT angiography (CTA). The patients had undergone either endovascular therapy (EVT) or IV rt-PA treatment (IVT), but not both. Large-vessel occlusion on admission CTA was defined as involvement of the internal carotid artery terminus (ICA-T), the middle cerebral artery main stem with or without bifurcation involvement (M1), or isolated involvement of the proximal M2 branches.

The primary outcome was 90-day favorable outcome, defined as a modified Rankin score of 0-2, while the safety outcomes were mortality and significant parenchymal hemorrhage.

Dr. Rai reported on results from 100 patients in the IVT group and 123 patients in the EVT group. The mean age of patients was 72 years, 56% were female, and their mean baseline National Institutes of Health Stroke Scale (NIHSS) score was 19.1. Nearly half of the occlusions (48%) involved M1, 32% involved M2, and 20% involved ICA-T.

Among all patients, a favorable outcome occurred in 81 (36.3%), and mortality occurred in 81 (36.3%).

A comparison of baseline characteristics revealed that patients in the EVT group were significantly younger than those in the IVT group (69 vs. 76 years; P = .0002), had significantly more M1 occlusions (56% vs. 38%; P = .007), and had significantly fewer M2 occlusions (20% vs. 46%; P = .0002).

A significantly greater proportion of patients in the EVT group had a favorable outcome compared with those in the IVT group (45% vs. 26%, P = .003; odds ratio, 2.3), yet there were no significant differences between the groups in terms of mortality (32% vs. 42%; P = .10) or in the rate of significant hemorrhage (14% vs. 10%; P = .38).

For all occlusion sites, patients in the EVT group had significantly better outcomes than did patients in the IVT group. For ICA-T occlusions, 27% of patients in the EVT group achieved a good outcome, compared with 0% in the IVT group (P = .004). Similar associations were observed for M1 lesions (41% vs. 11%, respectively; P = .0006) and for M2 lesions (76% vs. 48%; P = .01).

The researchers observed that at all sites of occlusion, a higher proportion of patients younger than 80 years had favorable outcomes, compared with patients aged 80 and older, especially those with proximal occlusions.

Multivariate analysis controlling for age and occlusion site composition demonstrated that patients in the EVT group were 3.9 times more likely to achieve a favorable outcome compared with their counterparts in the IVT group (P = .0004).

"In the last decade, we’ve seen significant technological advancement in our techniques and devices for stroke therapy," Dr. Rai commented. "The number of stroke treatments has not changed significantly. We need a paradigm shift in how we select patients for therapy, an appropriate intervention, and a comprehensive strategy."

Dr. Rai acknowledged certain limitations of the study, including its retrospective design and a bias in selecting EVT patients.

He said that he had no relevant financial disclosures.

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