A meta-analysis of 6756 patients in nine randomised trials suggested that irrespective of age or stroke severity, and despite an increased risk of fatal intracranial haemorrhage during the first few days after treatment, intravenous alteplase significantly improves the overall odds of a good stroke outcome when delivered within 4•5 h of stroke onset, with earlier treatment associated with bigger proportional benefits. Despite an average absolute increased risk of early death from intracranial haemorrhage of about 2%, by 3—6 months this risk was offset by an average absolute increase in disability-free survival of about 10% for patients treated within 3•0 h and about 5% for patients treated after 3•0 h, up to 4•5 h. Proportional treatment benefits and the relative increase in fatal intracranial haemorrhage from alteplase was similar irrespective of age or stroke severity, but the absolute excess risk attributable to alteplase was bigger among patients who had more severe strokes. Source: http://www.thelancet.com/一项包括9个随机临床试验，共6756例患者的荟萃分析表明，尽管用药后前几天致命性颅内出血的风险增大，中风发病4.5小时内静脉应用阿替普酶显著改善中风的整体预后，越早治疗则疗效成比例增加越大， 无论年龄大小或中风的严重程度。尽管因颅内出血而早逝的绝对风险平均增加了大约2％左右，经3-6个月此风险被平均约10％（3.0小时内得到治疗），及约5％（3.0 小时后至4.5小时内得到治疗）的无残疾生存率绝对增长所抵消。成比例性溶栓治疗的效果， 以及阿替普酶所致致命性颅内出血的相对增加与年龄或中风的严重程度无关，但归因于阿替普酶的致命性颅内出血的绝对额外风险则是在更严重的中风患者中更大。来源：http://www.thelancet.com/
