DWI-pc-ASPECT score in basilar artery occlusion: is 6 points or less always indicative of a bad outcome?

The prognosis of patients with acute basilar arterial occlusion after endovascular reperfusion therapy with diffusion-weighted imaging - posterior circulation-Alberta Stroke Program Early Computed Tomography Score (DWI-pc-ASPECTS) of 6 or less remains unclear. We aimed to assess the characteristics and prognosis of endovascular reperfusion therapy in patients with acute basilar arterial occlusion and DWI-pc-ASPECTS of 6 or less.

We analysed data collected from 1 January 2012 to 31 January 2018 in a prospective neuro-interventional registry of consecutive patients treated with endovascular reperfusion therapy. Clinical and imaging data on patients with DWI-pc-ASPECTS of 6 or less who underwent endovascular reperfusion therapy for acute basilar arterial occlusion were collected for this study. A good clinical outcome was defined as a modified Rankin scale of 2 or less at 90 days.

Forty-five acute basilar arterial occlusion patients with DWI-pc-ASPECTS of 6 or less were included. Among them, 11 (24.4%) patients had a good clinical outcome at 90 days. Patients with a good clinical outcome had less severe neurological symptoms at presentation (National Institutes of Health Stroke Scale (NIHSS) 19.0 (12.0-25.0) vs. 8.0 (6.0-11.5); P = 0.003) and were younger (72.5 years (57.0-80.0 years) vs. 63.0 years (55.5-69.0 years), P = 0.096) than those with a poor clinical outcome. The symptomatic intracranial haemorrhage rate was significantly higher in the poor clinical outcome group (13 (38.2%)) than in the good clinical outcome group (0 (0.0%)) (P = 0.045). In particular, in patients aged over 70 years, a favourable outcome was low (18 (52.9%) vs. 1 (9.1%); P = 0.027) even after successful recanalisation. In a multivariate model, a low initial NIHSS score (odds ratio 1.21; 95% confidence interval 1.07-1.44; P = 0.0093) and age over 70 years (odds ratio 15.27; 95% confidence interval 1.85-379.79; P = 0.0321) were independent predictors of poor clinical outcome.

Even with DWI-pc-ASPECTS of 6 or less, good clinical outcome can be achieved after endovascular reperfusion therapy. Relatively mild initial symptoms and younger age can predict a better outcome in acute basilar arterial occlusion patients with DWI-pc-ASPECTS of 6 or less.