BACKGROUND Type 2 myocardial infarction (T2MI) occurs because of an acute imbalance in myocardial oxygen supply and demand in the absence of atherothrombosis. Despite being frequently encountered in clinical practice, the population-based incidence and trends remain unknown, and the long-term outcomes are incompletely characterized. METHODS We prospectively recruited residents of Olmsted County, Minnesota, who experienced an event associated with a cardiac troponin T >99th percentile of a normal reference population (≥0.01 ng/mL) between January 1, 2003, and December 31, 2012. Events were retrospectively classified into type 1 myocardial infarction (T1MI, atherothombotic event), T2MI, or myocardial injury (troponin rise not meeting criteria for myocardial infarction [MI]) using the universal definition. Outcomes were long-term all-cause and cardiovascular mortality and recurrent MI. T2MI was further subclassified by the inciting event for supply/demand mismatch. RESULTS A total of 5460 patients had at least one cardiac troponin T ≥0.01 ng/mL; 1365 of these patients were classified as index T1MI (age, 68.5±14.8 years; 63% male) and 1054 were classified as T2MI (age, 73.7±15.8 years; 46% male). The annual incidence of T1MI decreased markedly from 202 to 84 per 100 000 persons between 2003 and 2012 (P<0.001), whereas the incidence of T2MI declined from 130 to 78 per 100 000 persons (P=0.02). In comparison with patients with T1MI, patients with T2MI had higher long-term all-cause mortality after adjustment for age and sex, driven by early and noncardiovascular death. Rates of cardiovascular death were similar after either type of MI (hazard ratio, 0.8 [95% CI, 0.7-1.0], P=0.11). Subclassification of T2MI by cause demonstrated a more favorable prognosis when the principal provoking mechanism was arrhythmia, in comparison with postoperative status, hypotension, anemia, and hypoxia. After index T2MI, the most common MI during follow-up was a recurrent T2MI, whereas the occurrence of a new T1MI was relatively rare (estimated rates at 5 years, 9.7% and 1.7%). CONCLUSIONS There has been an evolution in the type of MI occurring in the community over a decade, with the incidence of T2MI now being similar to T1MI. Mortality after T2MI is higher and driven by early and noncardiovascular death. The provoking mechanism of supply/demand mismatch affects long-term survival. These findings underscore the healthcare burden of T2MI and provide benchmarks for clinical trial design.

中文翻译：

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社区队列中 2 型心肌梗死的发生率、趋势和结果。

背景技术 2 型心肌梗塞 (T2MI) 的发生是因为在没有动脉粥样硬化血栓形成的情况下心肌氧供需严重失衡。尽管在临床实践中经常遇到，但基于人群的发病率和趋势仍然未知，并且长期结果的特征不完整。方法 我们前瞻性地招募了明尼苏达州奥姆斯特德县的居民，他们在 2003 年 1 月 1 日至 2012 年 12 月 31 日期间经历了与心肌肌钙蛋白 T > 正常参考人群 (≥0.01 ng/mL) 的第 99 个百分位相关的事件。使用通用定义回顾性分类为 1 型心肌梗死（T1MI，动脉粥样硬化事件）、T2MI 或心肌损伤（肌钙蛋白升高不符合心肌梗死 [MI] 的标准）。结果是长期全因和心血管死亡率以及复发性心肌梗死。T2MI 进一步细分为供需不匹配的诱因事件。结果 共有 5460 名患者至少有一个心肌肌钙蛋白 T ≥ 0.01 ng/mL；其中 1365 名患者被归类为指数 T1MI（年龄，68.5±14.8 岁；63% 男性），1054 名患者被归类为 T2MI（年龄，73.7±15.8 岁；46% 男性）。2003 年至 2012 年间，T1MI 的年发病率从每 100 000 人 202 例显着下降至 84 例（P<0.001），而 T2MI 的发生率从每 100 000 人 130 例降至 78 例（P=0.02）。与 T1MI 患者相比，T2MI 患者在调整年龄和性别后具有更高的长期全因死亡率，这是由早期和非心血管死亡驱动的。两种类型的 MI 后心血管死亡率相似（风险比，0.8 [95% CI，0.7-1.0]，P=0.11）。与术后状态、低血压、贫血和缺氧相比，当主要诱发机制为心律失常时，按原因对 T2MI 进行亚分类显示出更有利的预后。在指数 T2MI 之后，随访期间最常见的 MI 是复发性 T2MI，而新 T1MI 的发生相对罕见（估计 5 年发生率分别为 9.7% 和 1.7%）。结论 十多年来，社区中发生的 MI 类型发生了变化，现在 T2MI 的发病率与 T1MI 相似。T2MI 后的死亡率更高，并且由早期和非心血管死亡驱动。供需不匹配的诱发机制影响长期生存。