Recanalisation success is independent of ASPECTS in predicting outcomes after intra-arterial therapy for acute ischaemic stroke

Abstract

Intra-arterial (IA) therapy for stroke is an increasingly utilised management approach for acute ischaemic stroke. We aimed to correlate radiological characteristics and recanalisation success with radiological and functional outcomes at 90 days in patients treated with IA therapy. This was a single centre, retrospective study investigating the correlation between pre-procedural Computed Tomography-Angiogram Source Image (CTA-SI) Alberta Stroke Program Early Computed Tomography Score (ASPECTS), recanalisation success, and functional outcome at 90 days in patients with an acute ischaemic stroke from 2007-2012. Outcome measures were pre-procedural non-contrast computed tomography (NCCT), CTA-SI, and post-procedural NCCT ASPECTS that were obtained and analysed by three blinded reviewers, recanalisation success (Thrombolysis in Cerebral Infarction [TICI] 2b-3) and favourable clinical outcome (90 day modified Rankin scale [mRS] score ≤ 2). Forty-four patients satisfied the inclusion criteria. The mean age was 64.2 years (standard deviation: 14.9; median: 66.5; interquartile range [IQR]: 54.5-76.5). The median National Institutes of Health Stroke Scale score was 17 (IQR: 13.5-20). Twenty-one (47.7%) patients achieved a mRS score ≤ 2. The 90 day mortality rate was 25.0% (n=11). Of the patients who achieved TICI ≥ 2b-3, 65.5% (19/29) achieved mRS 2. There was a statistically significant association between recanalisation success (TICI 2b) and favourable neurological outcome at 90 days (odds ratio [OR] 25.22, 95% confidence interval [CI]: 2.86-222.37, p<0.005). Patients with high pre-procedural CTA-SI ASPECTS are significantly more likely to have high post-procedural NCCT score (OR 23.36, 95% CI: 3.26-166.92, p=0.002). Recanalisation success was strongly associated with good clinical outcome, unaffected by known predictive factors, which included age and stroke severity. This association was unattenuated by CTA-SI ASPECTS.

Keywords: Alberta Stroke Program Early Computed Tomography Score (ASPECTS); Computed Tomography Angiogram-Source Image (CTA-SI); Endovascular therapy; Intra-arterial therapy; Modified Rankin scale; Recanalisation success; Thrombolysis in Cerebral Infarction.