Efficacy of intravenous thrombolysis according to stroke subtypes: the M adrid S troke N etwork d ata

OBJECTIVES: To identify possible differences in the early response to intravenous thrombolysis (IVT) or in stroke outcome at 3 months, based on stroke subtype in patients with acute ischaemic stroke (IS). METHODS: Multicentre stroke registry data were used, with prospective inclusion of consecutive patients with acute IVT-treated IS in five acute stroke units. We compared clinical improvement (National Institutes of Health Stroke Scale, NIHSS) at 24 h and at day 7 as well as functional outcome at 3 months (Modified Rankin Scale, mRS) amongst the different stroke subtypes (ICD-10). RESULTS: In total, 1479 patients were included; 178 (12%) had large vessel disease (LVD) with carotid stenosis ≥ 50%, 175 (11.8%) had other LVD, 638 (43%) had cardioembolism, 60 (4.1%) had lacunar infarction, 72 (4.9%) were patients with IS of other/unusual cause and 356 (24.1%) had unknown/multiple causes. Patients with lacunar infarction had lower stroke severity (median NIHSS 6) whilst cardioembolic IS was the most severe (median NIHSS 14) (P < 0.001). No differences in NIHSS improvement were found at 24 h. LVD patients with carotid stenosis (odds ratio 0.544; 95% CI 0.383-0.772; P = 0.001) were less likely to improve at day 7 after adjustment for age, gender, vascular risk factors and stroke severity. However, adjusted multivariate analysis showed no influence of stroke subtype on stroke outcome (mRS) at 3 months. Age, systolic blood pressure on admission and stroke severity were independently associated with mRS > 2 at 3 months. CONCLUSION: Although LVD patients with arterial stenosis ≥ 50% improve less than the other aetiologies at day 7, stroke aetiological subtype does not determine differences in IS outcome at 3 months after IVT.