Climate change is increasing global average temperatures, as well as the frequency of extreme weather events. Both low and high ambient temperatures have been associated with elevated mortality; however, little is known about the cardiovascular impacts of hourly temperature. We assessed the association between hourly ambient temperature and risk of myocardial infarction (MI) across adult residents of New York State (NYS). We identified cases across NYS hospitals from 2000 to 2015 in the New York Department of Health Statewide Planning and Research Cooperative System dataset, using ICD codes. Hourly ambient temperature was assessed at each patient's residential ZIP code, up to 48 hours prior to MI. We employed a time-stratified case-crossover study design matching case to control periods on hour of day, day of week, month and year. Of the 791,695 primary MI hospital admissions, 45% were female, the mean (standard deviation; SD) age was 70 (15) years, and 49% of cases occurred among New York City residents. The observed temperature range was −29 °C to 39 °C, with a mean of 10.8 °C (10.5 °C). Temperature in the 6 h preceding the MI was positively associated with risk of MI, across the range of observed temperatures, with null or nearly null associations for earlier hours. We estimated a cumulative percent increase in hourly myocardial infarction rate of 7.9% (95% confidence interval [CI]: 5.2%, 10.6%) for an 11 °C (median) to 27 °C (95th percentile) temperature increase for lag hours 0–5. Men, Medicare-ineligible individuals (age < 65), and those experiencing their first MI were most sensitive. Our study provides evidence that increases in hourly ambient temperature can trigger myocardial infarction. Health-based definitions of extreme heat events may better capture the deleterious effects of heat by accounting for hourly temperature. Our findings can inform the design of more effective preparedness strategies for the increasingly frequent extreme heat events.

中文翻译：

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环境温度超短期变化会引发心肌梗塞吗？

气候变化正在增加全球平均气温以及极端天气事件的频率。环境温度低和高都与死亡率升高有关；然而，人们对每小时温度对心血管的影响知之甚少。我们评估了纽约州 (NYS) 成年居民每小时环境温度与心肌梗死 (MI) 风险之间的关联。我们使用 ICD 代码在纽约卫生部全州规划和研究合作系统数据集中识别了 2000 年至 2015 年纽约州各医院的病例。在心肌梗死发生前 48 小时内，每小时对每位患者居住的邮政编码处的环境温度进行评估。我们采用时间分层案例交叉研究设计来匹配案例来控制一天中的某一小时、一周中的某一天、一个月和一年的时间段。在 791,695 例原发性心肌梗死住院患者中，45% 为女性，平均（标准差；SD）年龄为 70 (15) 岁，49% 的病例发生在纽约市居民中。观察到的温度范围为 -29 °C 至 39 °C，平均值为 10.8 °C (10.5 °C)。在观察到的温度范围内，心肌梗死前 6 小时的温度与心肌梗死的风险呈正相关，而前几个小时的相关性为零或几乎为零。我们估计，滞后小时内温度升高 11 °C（中位数）至 27 °C（第 95 个百分位数）时，每小时心肌梗死率的累积百分比增加为 7.9%（95% 置信区间 [CI]：5.2%、10.6%） 0–5。男性、不符合医疗保险资格的个人（年龄 < 65 岁）和首次经历心肌梗死的人最为敏感。我们的研究提供的证据表明，每小时环境温度升高会引发心肌梗死。基于健康的极端高温事件定义可以通过考虑每小时的温度来更好地捕捉高温的有害影响。我们的研究结果可以为针对日益频繁的极端高温事件设计更有效的防备策略提供参考。