BACKGROUND The introduction of more sensitive cardiac troponin assays has led to increased recognition of myocardial injury in acute illnesses other than acute coronary syndrome. The Universal Definition of Myocardial Infarction recommends high-sensitivity cardiac troponin testing and classification of patients with myocardial injury based on pathogenesis, but the clinical implications of implementing this guideline are not well understood. METHODS In a stepped-wedge cluster randomized, controlled trial, we implemented a high-sensitivity cardiac troponin assay and the recommendations of the Universal Definition in 48 282 consecutive patients with suspected acute coronary syndrome. In a prespecified secondary analysis, we compared the primary outcome of myocardial infarction or cardiovascular death and secondary outcome of noncardiovascular death at 1 year across diagnostic categories. RESULTS Implementation increased the diagnosis of type 1 myocardial infarction by 11% (510/4471), type 2 myocardial infarction by 22% (205/916), and acute and chronic myocardial injury by 36% (443/1233) and 43% (389/898), respectively. Compared with those without myocardial injury, the rate of the primary outcome was highest in those with type 1 myocardial infarction (cause-specific hazard ratio [HR] 5.64 [95% CI, 5.12-6.22]), but was similar across diagnostic categories, whereas noncardiovascular deaths were highest in those with acute myocardial injury (cause specific HR 2.65 [95% CI, 2.33-3.01]). Despite modest increases in antiplatelet therapy and coronary revascularization after implementation in patients with type 1 myocardial infarction, the primary outcome was unchanged (cause specific HR 1.00 [95% CI, 0.82-1.21]). Increased recognition of type 2 myocardial infarction and myocardial injury did not lead to changes in investigation, treatment or outcomes. CONCLUSIONS Implementation of high-sensitivity cardiac troponin assays and the recommendations of the Universal Definition of Myocardial Infarction identified patients at high-risk of cardiovascular and noncardiovascular events but was not associated with consistent increases in treatment or improved outcomes. Trials of secondary prevention are urgently required to determine whether this risk is modifiable in patients without type 1 myocardial infarction. CLINICAL TRIAL REGISTRATION https://www.clinicaltrials.gov. Unique identifier: NCT01852123.

中文翻译：

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高灵敏度心肌肌钙蛋白和心肌梗塞的通用定义。

背景 引入更灵敏的心肌肌钙蛋白测定已导致对急性冠状动脉综合征以外的急性疾病中心肌损伤的认识增加。心肌梗塞的通用定义建议根据发病机制对心肌损伤患者进行高敏心肌肌钙蛋白检测和分类，但实施该指南的临床意义尚不清楚。方法 在一个阶梯楔形整群随机对照试验中，我们对 48 282 名疑似急性冠状动脉综合征的连续患者实施了高灵敏度心肌肌钙蛋白测定和通用定义的建议。在预先指定的二次分析中，我们比较了不同诊断类别的 1 年心肌梗死或心血管死亡的主要结局和非心血管死亡的次要结局。结果 实施使 1 型心肌梗死的诊断率提高了 11%（510/4471），2 型心肌梗死的诊断率提高了 22%（205/916），急性和慢性心肌损伤的诊断率提高了 36%（443/1233）和 43%（ 389/898），分别。与没有心肌损伤的患者相比，1 型心肌梗死患者的主要结局发生率最高（原因特异性风险比 [HR] 5.64 [95% CI，5.12-6.22]），但在诊断类别中相似，而非心血管死亡在急性心肌损伤患者中最高（原因特异性 HR 2.65 [95% CI, 2.33-3.01]）。尽管 1 型心肌梗死患者实施后抗血小板治疗和冠状动脉血运重建略有增加，但主要结果没有变化（原因特异性 HR 1.00 [95% CI，0.82-1.21]）。增加对 2 型心肌梗死和心肌损伤的认识并未导致调查、治疗或结果的变化。结论 高灵敏度心肌肌钙蛋白检测的实施和心肌梗死通用定义的建议确定了心血管和非心血管事件的高风险患者，但与治疗的持续增加或结局的改善无关。迫切需要进行二级预防试验以确定这种风险在没有 1 型心肌梗死的患者中是否可以改变。临床试验注册 https://www.clinicaltrials.gov。唯一标识符：NCT01852123。