Intravenous thrombolysis versus early antiplatelet therapy in acute ischaemic stroke with small artery occlusion.

Background: The efficacy of intravenous thrombolysis (IVT) versus early antiplatelet therapy (APT) in small artery occlusion (SAO) stroke remains debated.

Methods: Ischaemic stroke (IS) patients with SAO who received IVT or early APT without IVT≤4.5 hours from stroke onset were screened from a prospective multicentre IS registry study from 1 January to 1 June 2021. The primary outcome was unfavourable functional outcome (FO) at 3 months. The secondary outcome was early neurological deterioration (END). The safety outcome was symptomatic intracerebral haemorrhage (sICH).

Results: There were 1125 SAO patients with 394 receiving IVT. 411 patients (36.5%) exhibited unfavourable FO, and sICH occurred in 3 cases (0.27%), all in IVT group, at the follow-up. END was observed in 213 patients (18.9%). After propensity score matching and multivariable adjustment, IVT significantly reduced the likelihood of unfavourable FO at 3 months (aOR 0.447, 95% CI 0.305 to 0.656), but no significant difference was found in END (aOR 0.867, 95% CI 0.569 to 1.321). Clustering analysis identified two distinct phenotypes: phenotype 0 (characterised by traditional cardiovascular risk factors) and phenotype 1 (marked by prominent inflammatory markers). A significant treatment-by-phenotype interaction was observed (p=0.002), with a comparable magnitude of benefit in phenotype 0 (aOR 0.405, 95% CI 0.244 to 0.673) compared with phenotype 1 (aOR 0.414, 95% CI 0.218 to 0.783).

Conclusion: IVT significantly reduced the likelihood of unfavourable FO at 3 months in SAO patients but did not significantly reduce END. Patients with traditional risk factors may benefit more from IVT than those with elevated inflammatory markers.

Trial registration number: ChiCTR2100045258.