Dr. Seung-Jung Park 韩国亚洲心脏研究所主任
　　A study， which was recently published in Journal of American College of Cardiology， reported the outcomes of percutaneous coronary intervention (PCI) for unprotected left main coronary artery (ULMCA) stenosis from the National Cardiovascular Data Registry during 2004-2008 in the United States. PCI for ULMCA stenosis was carried out in less than 5% of 5，627 patients with ULMCA stenosis in 693 centers. The major finding of general outcomes was not encouraging. The composite incidence of death， myocardial infarction or repeat revascularization was 58% at 30 days. However， if we consider the baseline risk profiles of patients， the outcomes of this study are not surprising but predictable. The patients had the several comorbidities， with congestive heart failure in 81%， mean age of 72 years， renal failure in 13%， stroke in 21%， myocardial infarction in 38%， cardiogenic shock in 16%， chronic lung disease in 27%， and prior PCI in 30%. These are traditionally important risk factors of unfavorable outcomes of both PCI and bypass surgery. Presumably， many of the patients received PCI as a rescue alternative to bypass surgery due to the high surgical risks. In contrast， when patients were separated by urgency of procedure， the incidence of adverse outcomes was decreased by approximately 50% in the low-urgency group as compared with that of high-urgency procedure. Moreover， when patients were treated using drug-eluting stents， the risk of death was decreased compared with procedures using bare-metal stents. Although the mechanism is not clear， the mortality benefit may partly be related with the effect of drug-eluting stents in reducing recurrent stenosis in the left main. Currently， PCI for ULMCA stenosis is more standardized and operators are more experienced in low-risk patients. In addition， more exclusive use of drug-eluting stent， particularly safer new generation stents in current practices， plays a positive role in improving outcomes. Therefore， the practice patterns and outcomes of PCI for ULMCA stenosis should be repeatedly evaluated in the future.
　　一项NCDR注册研究提供了2004~2008年间经皮冠状动脉介入治疗无保护左主干（ULMCA）的临床结果。总体来说，结果不容乐观，30天时死亡、心肌梗死或再次血运重建的联合终点发生率为58%。但是如果考虑到患者的基线情况，这样的结果是不出意料的：81%的患者合并心力衰竭，平均年龄72岁，13%肾功能不全，21%卒中，38%心肌梗死，16%心源性休克，27%慢性肺病，30%有PCI史。这些均为PCI和搭桥手术的不良预后因素，这里我们假定这些患者因搭桥手术风险过高而采用PCI作为挽救手段。紧急度低的手术与紧急度高的手术相比，不良预后发生率减少了50%。药物洗脱支架（DES）与裸金属支架相比，死亡率下降，这可能与DES减少左主干内的再狭窄发生率有关。目前，ULMCA的PCI对低风险患者而言，更为标准化，术者更有经验；DES，尤其是更安全的新一代DES的使用，也有助于改善结果。因此，ULMCA 的PCI的临床使用情况和结果在将来需再次评估。