DETERMINANTS OF THE ONSET OF MYOCARDIAL INFARCTION

这项研究的目的是增加对以下方面的了解 急性心肌梗死的发作，进而将导致 更有效的预防性治疗。这项研究的动力 申请人最近提交的文件是否已开始生效 从早上6点开始，脑梗塞更加频繁。到中午比在其他时间 一天中的几次。这一事实引发了人们对普遍认为的- -但支持不佳--印象中心肌梗死 脑梗塞是一种随机事件。 马萨诸塞州的22个冠心病护理病房进行了一项研究 小组调查心肌梗死时间的决定因素 采用病例对照设计的脑梗塞发病。超过3.5年 期间，关于紧接在此之前的事件的详细信息 心肌梗塞的发病情况将从以下地点收集 大约7000名患者。与以下各项相关的相对风险 发病的假设风险因素将通过比较 在紧接心肌梗死前观察到的暴露频率 根据暴露频率得出期望值的脑梗塞 同一患者在一天中的其他时间和在其他时间 患者在一天中的同一时间。 将检验以下假设：1)沉淀剂 心肌梗死(在一天中的任何时间)，如假设 他直立的姿势，剧烈的体力活动，丰盛的饮食，以及 严重的情绪压力，将被识别出来。2)早高峰 发病时间越长，脑梗塞发病率越高，范围越小 根据人群的可变唤醒时间进行调整。3) β-受体阻滞剂可降低晨间发作的相对风险 和/或阿司匹林的使用。4)晨间脑梗塞的相对风险 不会因性别、年龄或吸烟而改变。 当脑梗塞发作与觉醒时间的关系为 澄清，并评估可能的沉淀物，增加 有关触发过程的信息将可用。是这样的 信息将有助于预防性治疗的设计， 然后可以在随机试验中进行评估。

The objective of this study is to gain increased knowledge about the onset of acute myocardial infarction which, in turn, will lead to more effective preventive therapy. The impetus for the study is the recent documentation by the applicants that the onset of infarction is more frequent from 6 a.m. to noon than during other times of the day. This fact calls into questions the widely held- -but poorly supported--impression that the onset of myocardial infarction is a random event. Twenty-two coronary care units in Massachusetts have formed a study group to investigate the determinants of the timing of myocardial infarction onset using a case-control design. Over a 3.5 year period, detailed information about the events immediately prior to the onset of myocardial infarction will be collected from approximately 7,000 patients. Relative risks associated with hypothesized risk factors for onset will be estimated by comparing observed exposure frequencies immediately prior to myocardial infarction with expected values derived from exposure frequencies in the same patients at other times of the day and in other patients at the same time of the day. The following hypotheses will be tested: 1) Precipitants of myocardial infarction (at any time of day) such as assumption of he upright posture, intense physical activity, a large meal, and acute emotional stress, will be identified. 2) The morning peak in infarct incidence will be higher and narrower when onset-time is adjusted for the variable wake-times of the population. 3) The relative risk of morning onset will e reduced by beta-blockade and/or aspirin usage. 4) The relative risk of morning infarction will not be altered by gender, age or cigarette smoking. When the relationship of infarction onset to time of awakening is clarified, and possible precipitants evaluated, increased information about triggering processes will be available. Such information will assist in the design of preventive therapy which can then be evaluated in randomized trials.