Predictors for Mortality after Mechanical Thrombectomy of Acute Basilar Artery Occlusion

Modern endovascular thrombectomy (MET), using stent retrievers or large-bore distal aspiration catheters in stroke patients with acute basilar artery occlusion (BAO), is routinely performed to date. However, more than 35% of BAO patients treated with MET die within 90 days despite high recanalization rates. The purpose of this study is to investigate the parameters associated with 90-day mortality in patients with BAO after MET.

We analyzed 117 consecutive BAO patients included in the Endovascular Treatment in Ischemic Stroke prospective clinical registry of consecutive acute ischemic stroke patients treated with MET (60 patients [51.3%] treated with a stent retriever as first-line technique) between March 2010 and April 2017. Successful recanalization was defined as modified thrombolysis In cerebral infarction scores 2b-3 at the end of MET, and mortality was defined as modified Rankin Scale 6 at 90 days. Associations of baseline characteristics (patient and treatment characteristics) and intermediate outcomes (recanalization, complications) with 90-day mortality were investigated in univariate and multivariate analyses.

Overall successful recanalization rate was 79.5, and 41.9% (95% CI 32.8-51.0%) of patients died within 90 days after MET. Patients with successful recanalization had a lower mortality rate (32.9 vs. 74.4%; p < 0.001). Failure of successful recanalization was an independent predictor of mortality (OR 5.1; 95% CI 1.34-19.33). In multivariate analysis, age ≥60 years (OR 6.37; 95% CI 1.74-23.31), admission National Institute of Health Stroke Scale (NIHSS) ≥13 (OR 4.62; 95% CI 1.42-15.03), lower posterior circulation-Alberta Stroke Program Early CT Score (pc-ASPECTS; OR 1.71; 95% CI 1.19-2.44), use of antithrombotic medication prior to stroke onset (OR 3.38; 95% CI 1.03-11.08), absence of intravenous thrombolysis (OR 3.36; 95% CI 1.12-10.03), and angioplasty/stenting of the basilar artery (OR 4.71; 95% CI 1.34-16.54) were independent predictors for mortality after MET.

Failure of successful recanalization was a strong predictor for mortality. In the setting of recanalization, age, admission NIHSS, pc-ASPECTS, absence of intravenous thrombolysis, and angioplasty/stenting of the basilar artery were also independent predictors for mortality after MET of BAO patients.