Early Recanalization After Tenecteplase or Alteplase in Distal and Medium Vessel Occlusion Strokes: An Observational Cohort Study.

BACKGROUND: Intravenous thrombolysis remains the standard treatment for distal and medium vessel occlusion (DMVO) strokes. However, unlike large vessel occlusions, whether tenecteplase achieves higher early successful recanalization rates than alteplase in DMVO strokes remains uncertain. METHODS: This single-center observational cohort study included consecutive patients with magnetic resonance imaging (MRI)-confirmed DMVO stroke treated at Centre Hospitalier Sud-Francilien, France, according to an institutional thrombolysis protocol specifying alteplase (0.9 mg/kg, 2016-2018) or tenecteplase (0.25 mg/kg, 2018-2023), with follow-up MRI 1 to 2 hours after intravenous thrombolysis. Patients intended for endovascular thrombectomy or without diagnostic-quality follow-up MRI were excluded. Recanalization was blindly assessed using a modified Arterial Occlusion Lesion scale designed for MRI and DMVO. Early successful recanalization was defined as ≥50% recanalization on early follow-up MRI (grade ≥2b), and substantial early infarct growth, assessed using a semiautomatic segmentation technique, was defined as a ≥0.5 mL and ≥20% increase in lesion volume. Propensity-score weighting accounted for baseline imbalances, including age, sex, vascular risk factors, baseline National Institutes of Health Stroke Scale score, occlusion site, and time period (2020-2023 versus 2016-2019). RESULTS: Of the 319 included patients, 159 were treated with tenecteplase and 160 with alteplase. Median baseline National Institutes of Health Stroke Scale was 3 (1-7) in the tenecteplase group versus 4 (1-7.5) in the alteplase group, while M2 occlusions accounted for 54.1% versus 43.8% of cases. Early successful recanalization, assessed at a median postintravenous thrombolysis time of 80 (70-94) minutes, occurred in 72 (45.3%) and 53 (33.1%) patients treated with tenecteplase and alteplase, respectively (propensity-score weighting-odds ratio, 1.59 [95% CI, 1.15-2.20]; P=0.005). Substantial early infarct growth was observed in 42 (26.8%) and 64 (40.5%) patients, respectively (propensity-score weighting-odds ratio, 0.49 [95% CI, 0.35-0.69]; P<0.0001). CONCLUSIONS: Compared with alteplase, tenecteplase-treated patients with DMVO had higher early successful recanalization and a lower risk of substantial early infarct growth, supporting its preferential use in this setting. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05635786.