Circulation：荟萃分析显示PCI减少心梗死亡率与减少自发性心梗呈平行关系

已有很多研究证实自发性心肌梗死（与再血管化治疗无关的心肌梗死）始终与死亡相关。PCI手术会引发包括心梗在内的相关并发症，但早先的研究发现围PCI手术期间发生的心肌梗死死亡率很低。由于研究人群、生物标记物测定、围PCI心梗定义的不同，围PCI心梗的发生率有很大不同，最高达50%，对围PCI心梗的临床预测价值有很大争议。另外，PCI术后生物标记升高值的容许范围及其临床预测价值也存在很大争议。研究者试图通过荟萃分析，明确PCI术与自发性心肌梗死、手术相关性心肌梗死及全因心肌梗死之间的相关性。

纽约大学医学院的Sripal Bangalore博士等，从PUBMED，EMBASE和CENTRAL检索了截止至2012年10月的相关随机临床试验（RCTs），所涉试验均为比较稳定性缺血性心脏疾病患者接受最佳药物治疗和PCI治疗的试验，均以心肌梗死包括自发性、PCI相关性和全因心肌梗死作为终点之一。获取各个试验的不同随访期限后，进行混合效应泊松回归分析。入选的12项随机试验，共随访患者37548例。

在这些患者中，较单独使用最佳药物治疗（OMT），PCI治疗后发生自发性非手术相关性心肌梗死的事件比率（IRR）显著降低（IRR IRR=0.76, 95% CI 0.58-0.99），但手术相关性心肌梗死的事件比率升高（IRR=4.11, 95% CI 2.53-6.88），两组间全因心梗的事件比率无差异（IRR=0.96, 95% CI 0.74-1.21）。全因死亡率和心血管死亡率的点预计在PCI组和最佳药物治疗组分别为0.88（95% CI 0.75-1.03）和0.70（95% CI 0.44-1.09），组间趋势与自发性非手术相关性心梗平行，但未达统计学显著性差异。

这一荟萃分析显示，与最佳药物治疗相比PCI治疗能显著降低自发性非手术相关性心梗的发生，但同时到时手术相关性心梗风险加大。总体上，PCI并不能减少全因心梗的发生率。这一结论与之前的研究中得出的自发性心梗与死亡率相关的结论一致。本研究中PCI治疗与最佳药物治疗相比，减少死亡率的点预计与PCI预防的自发性心梗的效应平行。不过，这只是统计学荟萃分析的结论，还需要进一步涉及相应研究以证实PCI减少自发性心梗与PCI减少死亡率之间的平行关系。

Percutaneous coronary intervention versus optimal medical therapy for prevention of spontaneous myocardial infarction in subjects with stable ischemic heart disease.
BACKGROUND
Contemporary studies have shown that spontaneous but not procedural myocardial infarction (MI) is related to subsequent mortality. Whether percutaneous coronary intervention (PCI) reduces spontaneous (nonprocedural) MI is unknown.
METHODS AND RESULTS
PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) were searched for randomized clinical trials until October 2012 comparing PCI with optimal medical therapy (OMT) for stable ischemic heart disease and reporting MI outcomes: spontaneous nonprocedural MI, procedural MI, and all MI, including procedure-related MI. Given the varying length of follow-up between trials, a mixed-effect Poisson regression meta-analysis was used. From 12 randomized clinical trials with 37 548 patient-years of follow-up, PCI compared with OMT alone was associated with a significantly lower incident rate ratio (IRR) for spontaneous nonprocedural MI (IRR=0.76; 95% confidence interval [CI], 0.58-0.99) at the risk of a higher rate of procedural MI (IRR=4.11; 95% CI, 2.53-6.88) without any difference in the risk of all MI (IRR=0.96; 95% CI, 0.74-1.21). The point estimate for PCI versus OMT for all-cause mortality (IRR=0.88; 95% CI, 0.75-1.03) and cardiovascular mortality (IRR=0.70; 95% CI, 0.44-1.09) paralleled that for spontaneous nonprocedural MI (but not procedural or all nonfatal MI), although these were not statistically significant.
CONCLUSIONS
PCI compared with OMT reduced spontaneous MI at the risk of procedural MI without any difference in all MI. Consistent with prior studies showing that spontaneous MI but not procedural MI is related to subsequent mortality, in the present report the point estimate for reduced mortality with PCI compared with OMT paralleled the prevention of spontaneous MI with PCI. Further studies are needed to determine whether these associations are causal.