Abah Udo, Garfjeld Roberts Patrick, Ishaq Muhammad, De Silva Ravi
Department of Cardiothoracic Surgery, John Radcliffe Hospital, Oxford, UK.
Interact Cardiovasc Thorac Surg. 2012 Jun;14(6):848-55. doi: 10.1093/icvts/ivs069. Epub 2012 Mar 8.
A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the use of warm or cold blood cardioplegia has superior myocardial protection. More than 192 papers were found using the reported search, of which 20 represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. A good breadth of high-level evidence addressing this clinical dilemma is available, including a recent meta-analysis and multiple large randomized clinical trials. Yet despite this level of evidence, no clear significant clinical benefit has been demonstrated by warm or cold blood cardioplegia. This suggests that neither method is significantly superior and that both provide similar efficacy of myocardial protection. The meta-analysis, including 41 randomized control trials (5879 patients in total), concluded that although a lower cardiac enzyme release and improved postoperative cardiac index was demonstrated in the warm cardioplegia group, this benefit was not reflected in clinical outcomes, which were similar in both groups. This theme of benefit in biochemical markers, physiological metrics and non-fatal postoperative events in the warm cardioplegia group ran throughout the literature, in particular the 'Warm Heart investigators' who conducted a randomized trial of 1732 patients, demonstrated a reduction in postoperative low output syndrome (6.1 versus 9.3%, P = 0.01) in the warm cardioplegia group, but no significant drop in 30-day all-cause mortality (1.4 versus 2.5%, P = 0.12). However, their later follow-up indicates non-fatal postoperative events predict reduced late survival, independent of cardioplegia. A minority of studies suggested a benefit of cold cardioplegia over warm in particular patient subgroups: One group conducted a retrospective study of 520 patients who required prolonged aortic cross-clamp times, results demonstrated less myocardial damage and reduced postoperative cardiac mortality and morbidity in the cold group. The clinical bottom line is that warm and cold cardioplegia result in similar short-term mortality. However, large studies have shown that warm cardioplegia reduces adverse post-operative events; the significance of which is unclear.
一篇心脏外科的最佳证据主题文章是按照结构化方案撰写的。所探讨的问题是使用温血或冷血心脏停搏液是否具有更好的心肌保护作用。通过报告的检索方式找到了192多篇论文，其中20篇代表了回答该临床问题的最佳证据。这些论文的作者、期刊、日期、发表国家、研究的患者群体、研究类型、相关结局和结果被制成表格。有大量高质量证据涉及这一临床困境，包括最近的一项荟萃分析和多项大型随机临床试验。然而，尽管有这样的证据水平，温血或冷血心脏停搏液均未显示出明显的临床益处。这表明两种方法都没有显著优势，且两者提供的心肌保护效果相似。该荟萃分析包括41项随机对照试验（共5879例患者），得出的结论是，尽管温血心脏停搏液组的心肌酶释放较低且术后心脏指数有所改善，但这种益处并未体现在临床结局上，两组的临床结局相似。温血心脏停搏液组在生化指标、生理指标和非致命性术后事件方面有益处这一主题贯穿于整个文献中，特别是“暖心研究者”对1732例患者进行的一项随机试验表明，温血心脏停搏液组术后低心排综合征有所减少（6.1%对9.3%，P = 0.01），但30天全因死亡率无显著下降（1.4%对2.5%，P = 0.12）。然而，他们后来的随访表明，非致命性术后事件预示着晚期生存率降低，与心脏停搏液无关。少数研究表明，在特定患者亚组中冷血心脏停搏液比温血心脏停搏液更有益：一组对520例需要延长主动脉阻断时间的患者进行了回顾性研究，结果表明冷血组的心肌损伤较小，术后心脏死亡率和发病率降低。临床要点是，温血和冷血心脏停搏液导致的短期死亡率相似。然而，大型研究表明温血心脏停搏液可减少术后不良事件；但其意义尚不清楚。
