Auerbach Andrew D, Goldman Lee
Department of Medicine, Box 0120, University of California-San Francisco, San Francisco, CA 94143-0120, USA.
JAMA. 2002 Mar 20;287(11):1435-44. doi: 10.1001/jama.287.11.1435.
Recent studies suggest that perioperatively administered beta-blockers may reduce the risk of adverse cardiac events in patients undergoing major noncardiac surgery.
To review the efficacy of perioperative beta-blockade in reducing myocardial ischemia, myocardial infarction, and cardiac or all-cause mortality from randomized trials.
A MEDLINE and conventional search of English-language articles published since 1980 was performed to gather information related to perioperative cardiac complications and beta-blockade. Reference lists from all relevant articles and published recommendations for perioperative cardiac risk management were reviewed to identify additional studies.
Prospective randomized studies (6) were included in the analysis if they discussed the impact of beta-blockade on perioperative cardiac ischemia, myocardial infarction, and mortality for patients undergoing major noncardiac surgery. Articles were examined for elements of trial design, treatment protocols, important biases, and major findings. These elements were then qualitatively compared.
We identified 5 randomized controlled trials: 4 assessed myocardial ischemia and 3 reported myocardial infarction, cardiac, or all-cause mortality. All studies sought to achieve beta-blockade before the induction of anesthesia by titrating doses to a target heart rate. Of studies reporting myocardial ischemia, numbers needed to treat were modest (2.5-6.7). Similarly modest numbers needed to treat were observed in studies reporting a significant impact on cardiac or all-cause mortality (3.2-8.3). The most marked effects were seen in patients at high risk; the sole study reporting a nonsignificant result enrolled patients with low baseline risk. As a group, studies of perioperative beta-blockade have enrolled relatively few carefully selected patients. In addition, differences in treatment protocols leave questions unanswered regarding optimal duration of therapy.
Despite heterogeneity of trials, a growing literature suggests a benefit of beta-blockade in preventing perioperative cardiac morbidity. Evidence from these trials can be used to formulate an effective clinical approach while definitive trials are awaited.
近期研究表明，围手术期使用β受体阻滞剂可能降低接受非心脏大手术患者发生不良心脏事件的风险。
回顾围手术期使用β受体阻滞剂在减少心肌缺血、心肌梗死以及随机试验中的心源性或全因死亡率方面的疗效。
对1980年以来发表的英文文章进行了医学文献数据库（MEDLINE）检索及常规检索，以收集与围手术期心脏并发症和β受体阻滞剂相关的信息。查阅了所有相关文章的参考文献列表以及已发表的围手术期心脏风险管理建议，以确定其他研究。
如果前瞻性随机研究（6项）讨论了β受体阻滞剂对接受非心脏大手术患者围手术期心脏缺血、心肌梗死和死亡率的影响，则纳入分析。检查文章的试验设计、治疗方案、重要偏倚和主要发现等要素。然后对这些要素进行定性比较。
我们确定了5项随机对照试验：4项评估心肌缺血，3项报告心肌梗死、心源性或全因死亡率。所有研究都试图通过滴定剂量至目标心率在麻醉诱导前实现β受体阻滞剂的阻滞作用。在报告心肌缺血的研究中，所需治疗人数适中（2.5 - 6.7）。在报告对心源性或全因死亡率有显著影响的研究中也观察到类似适中的所需治疗人数（3.2 - 8.3）。在高危患者中观察到最显著的效果；唯一一项报告无显著结果的研究纳入了基线风险较低的患者。总体而言，围手术期使用β受体阻滞剂的研究纳入的经过精心挑选的患者相对较少。此外，治疗方案的差异使得关于最佳治疗持续时间的问题仍未得到解答。
尽管试验存在异质性，但越来越多的文献表明β受体阻滞剂在预防围手术期心脏发病方面有益。在等待确定性试验的同时，这些试验的证据可用于制定有效的临床方法。
