Spontaneous recanalization in acute large core ischemic stroke due to large vessel occlusion: a post-hoc analysis of the ANGEL-ASPECT trial.

Background: Previous studies have indicated that a subset of patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) experience spontaneous recanalization (SR), but the prognosis and factors associated with SR in these individuals are not well characterized.

Methods: We conducted a post hoc secondary analysis of the Study of Endovascular Therapy in Acute Anterior Circulation Large Vessel Occlusive Patients with a Large Infarct Core (ANGEL-ASPECT) trial. SR in the medical management group was defined as a modified arterial occlusive lesion (AOL) grade of 2 or 3 on computed tomography angiography (CTA) or magnetic resonance angiography (MRA) at 36 hours (±12 hours).

Results: SR was detected in 67 out of 184 patients (36.4%) in the medical management (MM) group. The median age of patients was 67 years (interquartile range (IQR) 58-72), and 48 (71.6%) were male. The adjusted odds ratio (aOR) for 90-day modified Rankin Scale (mRS) score shift toward better outcomes of the MM with SR group vs the MM without SR group was 1.83, with marginally significant difference (95% confidence interval (CI) 0.992 to 3.36; P=0.053). No significant difference was found between the MM with SR group and EVT recanalization group (aOR 1.45; 95% CI 0.86 to 2.43; P=0.16) with similar findings in the inverse probability treatment weighting analysis (OR 0.85; 95% CI 0.49 to 1.48; P=0.57). Multivariable regression analysis showed that hypertension, atherothrombotic stroke and higher clot burden score were factors associated with SR.

Conclusions: SR in medically managed patients with acute large ischemic stroke caused by LVO was associated with good functional outcome. An improved understanding of SR patients may be helpful to develop therapeutic strategy in patients with large infarct due to LVO in anterior circulation.

Trial registration number: NCT04551664.