JAMA study Confirms Sustained Benefits of Endovascular Thrombectomy for Basilar Artery Occlusion at 1 Year

Basilar artery occlusion is a severe form of ischemic stroke with high disability and mortality rates. Whereas earlier trials have shown that EVT improves functional outcomes at 90 days compared to medical therapy alone, information on long-term outcomes beyond this period is scant. The ATTENTION trial provided pivotal evidence for the use of EVT within 12 hours from symptom onset. This extended study assessed whether benefits derived from EVT at 90 days were maintained or increased at 1 year.

The ATTENTION extension study followed-up patients with acute basilar artery occlusion treated within 12 hours of symptom onset from 36 comprehensive stroke centers. In all, 342 patients were randomized, of whom 330 [96.5%] had complete 1-year follow-up. Patients were treated in two conditions: EVT [thrombectomy group receiving mechanical endovascular thrombectomy] and best medical treatment, that is, the control group. The primary outcome was a favorable functional outcome defined as a modified Rankin Scale of 0 to 3 at 1 year. The secondary outcomes assessed functional independence, excellent outcome, level of disability across the full range of mRS scores, mortality, and health-related quality of life.

Key Findings

Primary Outcome (mRS 0-3 at 1 Year):

• Thrombectomy group: 44.6% (99/222)

• Control group: 19.4% (21/108)

• The adjusted rate ratio was 2.23 (95% CI, 1.51-3.29), with statistical significance of the thrombectomy group.

Excellent Outcome (mRS 0-1 at 1 Year):

• Thrombectomy group: 27.9% [62/222] v 19.9% at 90 days; Control group: 8.3% [9/108] v 7.9% at 90 days

Mortality

• Thrombectomy group: 45.5% [101/222] at 1 year v 36.7% at 90 days; Control group: 63.9% [69/108] at 1 year v 55.3% at 90 days

Secondary Outcomes:

• All mRS scores showed lower levels of disability in the thrombectomy group at 1 year.

• The benefit of EVT was particularly magnified in those patients who achieved an excellent outcome-e.g., mRS 0-1-only, further underlining the sustained and enhanced treatment effect.

The extended analysis herein of the 1-year follow-up data reinforces long-term benefits of EVT for patients with basilar artery occlusion. In contrast with the rates at 90 days, mortality rates increased for both groups; however, EVT patients maintained better functional outcomes and further improved in achieving excellent recovery. The findings of this study point toward the importance of EVT in the management of acute basilar artery occlusion, where a considerable proportion of patients are able to achieve favorable outcomes even at 1 year post-stroke.

In conclusion, EVT establishes ongoing benefits in patients with acute basilar artery occlusion along with superior functional and improved survival at 1-year outcomes compared to best medical treatment. These results assure that timely EVT intervention is indeed associated with an improvement in the long-term prospects for the recovery of stroke patients.

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