讨 论
试验结果表明,按照常规临床方法使用阿替普酶对急性缺血性卒中患者进行治疗,3~4.5 h治疗组与3 h内治疗组间的症状性脑出血发生率、病死率及3个月时生活自理能力相似。试验结果为一项荟萃分析研究提议(将缺血性卒中静脉溶栓治疗的时间窗延长至发病后4.5 h)的建议提供了支持[3]。虽然该项荟萃分析的研究结果尚需诸如ECASS-Ⅲ[18]的独立随机对照试验加以证实,但本试验的主要价值在于提供了在延长的时间窗内按照常规临床方法使用阿替普酶治疗缺血性卒中的安全性的信息。
对急性缺血性卒中患者使用阿替普酶溶栓处理是治疗此类致残率高且花费高昂疾病的一个重要进展。阿替普酶过去只限于对在发病后3 h内到达医院的一小部分患者使用,并且仅限于在能够及时提供专业医疗护理的医院使用。关注与SITS-MOST队列研究相应的针对阿替普酶扩大使用的随机对照试验结果比关注阿替普酶常规临床应用的安全性和有效性更有益[1]。
静脉输注阿替普酶的3 h时间窗现已经成为所有卒中治疗的国际性指南的推荐标准,其推荐依据是NINDS研究[4](一项在卒中溶栓治疗方面取得重要成果的大型研究)结果证明在卒中发病后3 h内行阿替普酶溶栓处理有显著益处;而其他随机试验发现如果超过或明显超过3 h时限才开始行阿替普酶治疗则效果不明显[7-8]。SITS医疗中心的数据显示,在其治疗的所有患者中只有很小一部分病例(4%)是在发病后3~4.5 h接受阿替普酶溶栓治疗的;而大部分病例(74%)是在3 h内接受治疗的(其余22%的病例因不符合现行的阿替普酶使用标准而放弃使用)。SITS-ISTR研究未给出超过3 h时限后仍行阿替普酶溶栓治疗的原因。其中一个原因可能是患者已经做好准备且知情阿替普酶溶栓治疗的3 h时限,但由于在治疗开始前的评估期内出现无法预知的延搁而导致超出3 h时限,这种情况下临床医师不愿意放弃使用阿替普酶治疗;另外一个原因可能是,有些临床医师依据前述荟萃分析对所有可用数据进行研究后所做出的有效性结论,而决定将阿替普酶治疗时间延长至卒中发病后4.5 h[3]。但是,该项荟萃分析的研究结果也明确表明阿替普酶治疗效果具有时间依赖性。本试验3~4.5 h治疗组中有半数病例是在超出3 h时限后的15 min内接受阿替普酶治疗的,而两组间从卒中发病至开始治疗间隔时间的中位数相差55 min,这种现象值得注意。这一现象可被视为临床医师为尽可能使阿替普酶开始治疗时间接近3 h时限而努力的证明。
ECASS Ⅰ和ECASS Ⅱ试验提出阿替普酶起始治疗的时间窗为0~6 h[5–6]。荟萃分析综合研究了上述试验与ATLANTIS试验的结果后,提出了阿替普酶起始治疗时间延长至卒中发病后4.5 h仍具有显著疗效的结论[7-8]。ATLANTIS研究B试验的研究者分析了547例在卒中发病后3~5 h内行阿替普酶治疗的患者,其选择的时间间隔与本研究相似[7]。ATLANTIS研究中积极治疗组患者发病至治疗时间间隔的中位数为276 min,这一结果说明积极治疗组中仅有约半数病例的阿替普酶起始治疗时间窗为3~4.5 h,仅有20%的病例在发病后3~4 h内行阿替普酶治疗。ATLANTIS研究两个试验组中受试者的年龄中位数相同(66岁),男女比例为60∶40,此数据与SITS-ISTR研究相似。ATLANTIS研究中受试者基线NIHSS评分的中位数比SITS-ISTR研究低1分(10分 vs 11分)。ATLANTIS研究中积极治疗组改良Rankin量表评分达到0~1分的病例为42%,而SITS-ISTR研究中这一比例为41%。ATLANTIS研究中3~5 h治疗组的病死率为11.0%,本研究中为12.7%。SITS-ISTR研究中3~4.5 h治疗组两种定义的症状性脑出血发生率共计17%,ATLANTIS研究为18%。其中,符合NINDS定义的症状性脑出血发生率在SITS-ISTR研究和ATLANTIS研究中分别为8%和7%。SITS-ISTR研究中3~4.5 h治疗组与ATLANTIS研究B试验的积极治疗组之间的主要差异在于阿替普酶起始治疗时间不同(两组间发病至治疗间隔时间的中位数相差81 min);即便如此,两项研究的结果也非常相似。
在获取观测数据的方法设计上存在局限性是本研究与3~4.5 h治疗组数据分析的缺陷之一。本研究是一项大规模、多国联合及多医疗中心参与的研究,目的为指导常规临床实践而收集数据。本研究中不同医疗中心在认识和技术上的差异可能会影响其对颅内出血的评估,通常颅内出血由当地研究者负责报告。此外,对超过3 h时限的患者是否行阿替普酶治疗可能有选择性偏倚是本研究的另一个缺陷。尽管3~4.5 h治疗组中分别在3~4.5 h时间段的前期和后期行阿替普酶治疗的疗效一致,但由于3 h时限过后不久即行阿替普酶治疗的患者占较大比重,所以对阿替普酶在3~4.5 h时间段内后期的疗效下结论仍需谨慎。虽然试验通过多变量分析校正了各指标的基线差异,但这种校正并不能消除所有差异。从患者年龄、性别或卒中严重程度等数据上看,尽管3 h时限后接受治疗的患者基线年龄偏小,神经功能障碍的基线严重程度偏轻(表1),但是试验并未发现明确的证据证明对3~4.5 h的患者行阿替普酶治疗存在选择性。此外,3~4.5 h治疗组中有高血压或高血脂病史的患者比例比3 h内治疗组均低。本研究中严重卒中患者普遍比轻度卒中患者较早到达卒中治疗中心,接受治疗也相应较早。在3~4.5 h的延长时间窗内治疗的病例中有新的脑梗死征象(通过CT扫描发现)的患者更多,且这些患者在有卒中溶栓治疗经验的医疗中心接受阿替普酶治疗的可能性更大,这一现象说明临床医师对溶栓疗法的熟悉程度会影响其决定是否对超过3 h时限的患者行阿替普酶治疗。
该项观察性队列研究调查了大量发病后3~4.5 h积极施行阿替普酶治疗的病例,而其他一些观察性研究调查病例的起始治疗时间甚至超出了本研究确定的时间段[19–20]。本研究中关于在各种不同的临床时间点常规使用阿替普酶的安全性数据有益于决策机构和临床指导小组做出延长阿替普酶溶栓治疗时间窗的决定。
本研究结果显示拟行静脉溶栓治疗的患者只要符合欧洲产品特征概要适用标准,在3 h时限过后的短期内使用阿替普酶仍然安全。当然,该试验结果并非鼓励放弃及早治疗的努力,因为对多项随机对照试验的数据进行汇总分析后,提示阿替普酶溶栓治疗的疗效具有时间依赖性,这就要求有最佳方案以尽早使用阿替普酶治疗急性缺血性卒中。
Lancet 2008; 372: 1303–09
(李青波 译)
Acknowledgments:
SITS-ISTR is funded by an unrestricted grant from Boehringer-Ingelheim, and by a grant from European Union Public Health Executive Authority (PHEA). Financial support was also provided through the regional agreement on medical training and research (ALF) between Stockholm County Council and the Karolinska Institute. Zoe A Preston received funding from Boehringer Ingelheim to provide editorial assistance in the coordination of the submission. The views expressed are those of the authors. Uppsala Clinical Research (UCR) centre (Sweden) develops, maintains, and upgrades the software for SITS register in close collaboration with SITS. UCR team members are Sören Gustavsson, Botond Pakucs, Olof Felton, and Niclas Eriksson. Alteplase (recombinant tissue plasminogen activator) is not approved in the USA or Europe for routine use in acute ischaemic stroke when initiated beyond 3 h from symptom onset. We thank all the SITS-ISTR investigators and their centres for their participation (webappendix), and all the patients who participated in SITS-ISTR.
Department of Clinical Neurosciences, Karolinska Institutet, Stockholm, Sweden (Prof N Wahlgren MD, N Ahmed MD); Department of Neurosciences, Hospital Universitari Germans Trias i Pujol, Barcelona, Spain (Prof A Dávalos MD, M Millán MD); Department of Neurology, University of Heidelberg, Germany (Prof W Hacke MD); Division of Clinical Neurosciences, Faculty of Medicine (K Muir MD) and Department of Medicine (Prof K R Lees FRCP), University of Glasgow, Glasgow, UK; Department of Neurology, Turku University Central Hospital, Turku, Finland (R Roine MD); Department of Neurology, Department of Neurological Sciences, University "La Sapienza", Rome, Italy (Prof D Toni MD)
Correspondence to: Prof Nils Wahlgren, SITS International Coordination Office, Department of Neurology, Karolinska University Hospital, SE-171 76 Stockholm, Sweden (e-mail: nils.wahlgren@karolinska.se)
参考文献
1. Wahlgren N, Ahmed N, Dávalos A, et al. Thrombolysis with alteplase for acute ischaemic stroke in the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST): an observational study. Lancet, 2007, 369: 275–82
2. Wahlgren N, Ahmed N, Eriksson N, et al. Safe Implementation of Thrombolysis in Stroke-MOnitoring STudy (SITS-MOST): multivariable analysis of outcome predictors and adjustment of main outcome results to baseline data profile in randomized controlled trials. Stroke 2008 (in press)
3. Hacke W, Donnan G, Fieschi C, et al. Association of outcome with early stroke treatment: pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials. Lancet, 2004, 363: 768–74
4. Tissue plasminogen activator for acute ischemic stroke. The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. N Engl J Med, 1995, 333: 1581–87
5. Hacke W, Kaste M, Fieschi C, et al. Intravenous thrombolysis with recombinant tissue plasminogen activator for acute hemispheric stroke. The European Cooperative Acute Stroke Study (ECASS). JAMA, 1995, 274: 1017–25
6. Hacke W, Kaste M, Fieschi C, et al. for the Second European-Australasian Acute Stroke Study Investigators. Randomised double-blind placebo-controlled trial of thrombolytic therapy with intravenous alteplase in acute ischaemic stroke (ECASS II). Lancet, 1998, 352: 1245–51
7. Clark WM, Wissman S, Albers GW, et al. Recombinant tissue-type plasminogen activator (Alteplase) for ischemic stroke 3 to 5 hours after symptom onset. The ATLANTIS Study: a randomized controlled trial. Alteplase Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke. JAMA, 1999, 282: 2019–26
8. Clark WM, Albers GW, Madden KP, et al. The rtPA (alteplase) 0- to 6-hour acute stroke trial, part A (A0276g): results of a double-blind, placebo-controlled, multicenter study. Thrombolytic therapy in acute ischemic stroke study investigators. Stroke, 2000, 31: 811–16.
9. SITS-ISTR (Safe Implementation of Treatments in Stroke-International Stroke Thrombolysis Register). http://www. acutestroke.org (accessed Aug 8, 2008)
10. European Stroke Organisation (ESO) Executive Committee: ESO Writing Committee: guidelines for management of ischaemic stroke and transient ischaemic attack 2008. Cerebrovasc Dis, 2008, 25: 457–507
11. Adams HP, del Zoppo G, Albert MJ, et al. Guidelines for the early management of adults with ischemic stroke. Stroke, 2007, 38: 1655–711
12. Brott T, Adams H, Olinger C. Measurements of acute cerebral infarction, a clinical examination scale. Stroke, 1989, 20: 864–70
13. Wardlaw JM, Sandercock PA, Berge E. Thrombolytic therapy with recombinant tissue plasminogen activator for acute ischemic stroke: where do we go from here? A cumulative meta-analysis. Stroke, 2003, 34: 1437–42
14. Larrue V, von Kummer RR, Muller A, et al. Risk factors for severe hemorrhagic transformation in ischemic stroke patients treated with recombinant tissue plasminogen activator: a secondary analysis of the European-Australasian Acute Stroke Study (ECASS II). Stroke, 2001, 32: 438–41
15. van Swieten JC, Koudstaal PJ, Visser MC, et al. Interobserver agreement for the assessment of handicap in stroke patients. Stroke, 1988, 19: 604–07
16. Newcombe RG. Two-sided confidence intervals for the single proportion: comparison of seven methods. Stat Med, 1998, 17: 857–72
17. Adams HP Jr, Bendixen BH, Kappelle LJ, et al. Classification of subtype of acute ischemic stroke. Definitions for use in a multicenter clinical trial. TOAST. Stroke, 1993, 24: 35–41
18. Hacke W, Kaste M, Bluhmki E, et al, for the European Cooperative Acute Stroke Study (ECASS) investigators. Alteplase compared with placebo within 3 to 4.5 hours for acute ischemic stroke. N Engl J Med (in press)
19. Uyttenboogaart M, Vroomen PC, Stewart RE, et al. Safety of routine IV thrombolysis between 3 and 4.5 h after ischemic stroke. J Neurol Sci, 2007, 254: 28–32
20. Schellinger PD, Thomalla G, Fiehler J, et al. MRI-based and CT-based thrombolytic therapy in acute stroke within and beyond established time windows: an analysis of 1210 patients. Stroke, 2007, 38: 2640–45