Comparative safety and efficacy of 0.6 mg/kg versus 0.9 mg/kg alteplase in acute ischemic stroke: a systematic review and meta-analysis.

BACKGROUND: Alteplase is the standard thrombolytic therapy for acute ischemic stroke, with 0.9 mg/kg as the widely recommended dose. However, a lower dose of 0.6 mg/kg has been used, particularly in some populations, to reduce bleeding risk. We conducted a meta-analysis to compare the efficacy and safety of 0.6 mg/kg versus 0.9 mg/kg alteplase. METHODS: A systematic search identified 11 observational studies and randomized controlled trials totaling 6,148 patients who received either low-dose or standard-dose alteplase within 4.5 h of symptom onset. Outcomes evaluated included symptomatic intracranial hemorrhage (sICH), any intracranial hemorrhage (ICH), 90-day mortality, in-hospital mortality, and functional outcomes measured by the modified Rankin Scale (mRS). Random-effects meta-analyses generated pooled odds ratios (OR) with 95% confidence intervals (CI). RESULTS: Low-dose alteplase was associated with a significantly lower risk of sICH compared to standard-dose (OR 0.51, 95% CI 0.35-0.76, p = 0.0008). No significant differences were observed in any ICH (OR 1.00, 95% CI 0.84-1.19, p = 0.99), 90-day mortality (OR 0.86, 95% CI 0.71-1.04, p = 0.12), or functional independence defined by mRS 0-1 at 90 days (OR 0.90, 95% CI 0.80-1.01, p = 0.09). Heterogeneity was low to moderate across outcomes. CONCLUSION: Low-dose alteplase may reduce the risk of symptomatic hemorrhage without compromising mortality or functional recovery. These findings support consideration of dose individualization in clinical practice, warranting further prospective validation.