Eur Heart J：研究发现多个因素影响经皮冠状动脉介入术后缺血后处理诱导的心肌保护效应

及时恢复冠脉灌注是ST段升高急性心肌梗死病人的最有效的治疗策略，可以减少梗死面积，改善预后。然而，缺血心肌的再灌注本身会对心脏造成再灌注损伤。临床上需要寻找应对缺血再灌注损伤的有效方法。缺血后处理可以预防再灌注损伤诱导的内皮功能障碍。中国医学科学院一研究小组采用系统回顾和meta分析方法，结果显示影响ST段升高的心肌梗死病人在经皮冠状动脉介入术后缺血后处理的潜在因素有支架置入术、性别、年龄等因素。

本研究系统回顾了截止2012年2月，在pubmed、医学文摘和Cochrane图书馆内的10次随机对照试验，共560位ST段抬高急性心肌梗死病人，主要是关于缺血后适应影响心肌酶或左心室射血分数的报道。与对照组相比，缺血后处理明显降低心肌酶水平[标准差=-0.84；95%可信区间：-1.26至-0.43；P<0.00001;异质性测试，I（2）=81.0%]，改善了左心室射血分数[加权平均值=3.98%；95%可信区间：1.27-6.70%；P=0.004；异质性测试，I（2）=87.1%]。1年后对左心室射血分数的影响仍明显存在（加权平均值=5.04%；95%可信区间：4.20-5.88%；P<0.00001；异质性测试，I（2）=0.0%）。单因素的meta回归分析结果提示明显异质性（P<0.1）的主要来源是直接支架置入技术的应用率（系数=-0.886；P=0.069；调整R（2）=0.34）和男性比例（系数=-0.022；P=0.098；调整R（2）=0.28），二者影响心肌酶水平，而年龄（系数=-1.34；P=0.025；调整R（2）=0.55）影响左心室射血分数。多元回归和亚组分析也证实了这些结果。

研究结论，10次随机对照试验的系统回顾和meta分析结果提示缺血后处理可能具有心肌保护功能，依据是：经皮冠状动脉介入术期间，ST段升高的急性心肌梗死病人的心肌酶水平和左心室射血分数的改善。这些影响对年轻和男性患者以及应用直接支架置入术的病人更为明显。将来研究应该关注高质量大规模临床试验的长期随访病人的死亡率。

Stenting technique, gender, and age are associated with cardioprotection by ischaemic postconditioning in primary coronary intervention: a systematic review of 10 randomized trials
Aims
We sought to perform a systematic review and meta-analysis to evaluate the potential factors affecting ischaemic postconditioning (IPoC) for patients with ST-segment elevation acute myocardial infarction (STEMI) in primary percutaneous coronary intervention (PCI).
Methods and results
Ten randomized controlled trials (RCTs) on IPoC reporting myocardial enzyme levels or left ventricular ejection fraction (LVEF) in a total of 560 STEMI patients were identified in PubMed, EMBase, and Cochrane Library (up to February 2012). Compared with controls, IPoC significantly reduced elevated cardiac enzyme levels [standardized mean difference = −0.84; 95% confidential interval (CI): −1.26 to −0.43; P < 0.00001; heterogeneity test, I2 = 81.0%] and improved LVEF [weighted mean difference (WMD) = 3.98%; 95% CI: 1.27–6.70%; P = 0.004; heterogeneity test, I2 = 87.1%]. The effect on LVEF remained significant after 1 year (WMD = 5.04%; 95% CI: 4.20–5.88%; P < 0.00001; heterogeneity test, I2 = 0.0%). Univariate meta-regression analysis suggested that the major sources of significant heterogeneity (P < 0.1) were the use of direct-stenting technique (%) (coefficient = −0.886; P = 0.069; adjusted R2 = 0.34) and male proportion (%) (coefficient = −0.022; P = 0.098; adjusted R2 = 0.28) for myocardial enzyme levels, and age (coefficient = −1.34; P = 0.025; adjusted R2= 0.55) for LVEF (%). Subsequent multivariate regression and subgroup analysis confirmed these results.
Conclusion
Available evidence from this systematic review and meta-analysis of 10 RCTs suggests that IPoC may confer cardioprotection in terms of myocardial enzyme levels and LVEF for STEMI during primary PCI. These effects are more pronounced among young and male patients, and those in whom direct-stenting techniques were used. Future studies should focus on the mortality in high-quality, large-scale clinical trials with long-term follow-up.