Intravenous thrombolysis with tissue-plasminogen activator in small vessel occlusion

Intravenous tissue-plasminogen activator (IV-TPA) treatment in acute ischemic stroke (AIS) patients due to small vessel occlusion (SVO) has been debated because of its small expected benefit and symptomatic intracranial hemorrhage (SICH) risk. Furthermore, data on subgroups of SVO patients are limited. From a prospective multicenter stroke registry database, AIS patients due to SVO within 24 h from onset were selected. Efficacy outcomes were 3-month modified Rankin Scale (mRS) score 0-1 proportion and mRS score distribution. Additionally, subgroup analyses were conducted by age, sex, initial National Institute Health Stroke Scale (NIHSS) score, and presenting limb paresis. This study included 2482 patients: 193 in the IV-TPA group and 2289 in the control group. After adjusting covariates, IV-TPA treatment was associated with an increased mRS 0-1 outcome (adjusted OR [95% CI], 1.56 [1.06-2.29]; P = 0.0249), but was not significantly associated with a favorable mRS shift (1.33 [0.98-1.81]; P = 0.0709). SICH and 3-month death occurred in three (1.6%) and none in the IV-TPA group versus one (0.04%) and 16 (0.7%) in the control group. In subgroup analyses, the IV-TPA effect appeared significantly greater in patients aged ≥80 versus <80 for mRS score distribution (P_interaction = 0.012). This study showed that, in SVO patients, IV-TPA within 4.5 h may improve functional outcome with a low SICH risk. The benefit appeared more substantial in patients aged ≥80.