Background: Contemporary ST-segment–elevation myocardial infarction management involves primary percutaneous coronary intervention, with ongoing studies focusing on infarct size reduction using ancillary therapies. N-acetylcysteine (NAC) is an antioxidant with reactive oxygen species scavenging properties that also potentiates the effects of nitroglycerin and thus represents a potentially beneficial ancillary therapy in primary percutaneous coronary intervention. The NACIAM trial (N-acetylcysteine in Acute Myocardial Infarction) examined the effects of NAC on infarct size in patients with ST-segment–elevation myocardial infarction undergoing percutaneous coronary intervention.

Methods: This randomized, double-blind, placebo-controlled, multicenter study evaluated the effects of intravenous high-dose NAC (29 g over 2 days) with background low-dose nitroglycerin (7.2 mg over 2 days) on early cardiac magnetic resonance imaging–assessed infarct size. Secondary end points included cardiac magnetic resonance–determined myocardial salvage and creatine kinase kinetics.

Results: Of 112 randomized patients with ST-segment–elevation myocardial infarction, 75 (37 in NAC group, 38 in placebo group) underwent early cardiac magnetic resonance imaging. Median duration of ischemia pretreatment was 2.4 hours. With background nitroglycerin infusion administered to all patients, those randomized to NAC exhibited an absolute 5.5% reduction in cardiac magnetic resonance–assessed infarct size relative to placebo (median, 11.0%; [interquartile range 4.1, 16.3] versus 16.5%; [interquartile range 10.7, 24.2]; P=0.02). Myocardial salvage was approximately doubled in the NAC group (60%; interquartile range, 37–79) compared with placebo (27%; interquartile range, 14–42; P<0.01) and median creatine kinase areas under the curve were 22 000 and 38 000 IU·h in the NAC and placebo groups, respectively (P=0.08).

Conclusions: High-dose intravenous NAC administered with low-dose intravenous nitroglycerin is associated with reduced infarct size in patients with ST-segment–elevation myocardial infarction undergoing percutaneous coronary intervention. A larger study is required to assess the impact of this therapy on clinical cardiac outcomes.

Clinical Trial Registration: Australian New Zealand Clinical Trials Registry. URL: http://www.anzctr.org.au/. Unique identifier: 12610000280000.

中文翻译：

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在接受经皮冠状动脉介入治疗ST段抬高型心肌梗死的患者中，早期使用N-乙酰半胱氨酸和硝酸盐疗法可减少心肌梗死的大小（NACIAM试验[急性心肌梗死中的N-乙酰半胱氨酸]）

背景：当代ST段抬高型心肌梗死的治疗涉及主要的经皮冠状动脉介入治疗，目前正在进行的研究侧重于使用辅助疗法缩小梗死面积。N-乙酰半胱氨酸（NAC）是具有活性氧清除能力的抗氧化剂，还增强了硝酸甘油的作用，因此代表了潜在的有益的辅助性治疗，主要用于经皮冠状动脉介入治疗。NACIAM试验（N-乙酰半胱氨酸在急性心肌梗死中）研究了NAC对接受经皮冠状动脉介入治疗的ST段抬高型心肌梗死患者的梗死面积的影响。

方法：这项随机，双盲，安慰剂对照的多中心研究评估了静脉高剂量NAC（29 g，历时2天）和背景低剂量硝酸甘油（7.2 mg，历时2天）对早期心脏磁共振成像的影响–评估梗死面积。次要终点包括心脏磁共振测定的心肌挽救和肌酸激酶动力学。

结果：在112例ST段抬高的心肌梗死随机患者中，有75例（NAC组为37例，安慰剂组为38例）接受了早期心脏磁共振成像。缺血预处理的中位持续时间为2.4小时。所有患者均接受本底硝酸甘油输注，相对于安慰剂，随机分入NAC的患者经心脏磁共振评估的梗塞面积绝对减少了5.5％（中位值为11.0％； [四分位间距4.1、16.3]比16.5％； [四分位间距10.7，24.2]; P = 0.02）。与安慰剂（27％；四分位间距：14-42；P）相比，NAC组的心肌抢救率（60％；四分位间距为37-79）大约翻了一番。NAC组和安慰剂组的<0.01）和曲线下的中位肌酸激酶面积分别为22000和38 000 IU·h（P = 0.08）。

结论：经皮冠状动脉介入治疗的ST段抬高型心肌梗死患者，大剂量静脉内NAC联合小剂量静脉内硝酸甘油可减少梗死面积。需要进行一项更大的研究来评估这种疗法对临床心脏预后的影响。

临床试验注册：澳大利亚新西兰临床试验注册处。网址：http : //www.anzctr.org.au/。唯一标识符：12610000280000。