Epidemiology Of Silent Myocardial Ischemia In Apparently

无症状性心肌缺血的流行病学

• 批准号: 6674172
• 负责人: Samer Najjar
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6674172
• 关键词: aging; cardiovascular disorder diagnosis; cardiovascular disorder epidemiology; cardiovascular disorder prevention; clinical research; coronary disorder; diagnosis design /evaluation; exercise; heart rate; human subject; myocardial ischemia /hypoxia

SUMMARY OF WORK: Our laboratory uses multiple approaches to investigate potential predictors of coronary heart disease in apparently healthy subjects. A. The rate at which heart rate (HR) declines after cessation of maximal treadmill exercise has been proposed as an independent predictor of future coronary events (CE) both in symptomatic and asymptomatic populations. To examine this hypothesis in apparently healthy subjects, we determined the relationship between the decline in HR between peak exercise and 2 minutes post-exercise (HR recovery-2') in over 1000 Baltimore Longitudinal Study of Aging (BLSA) volunteers and subsequent development of CE (angina pectoris, myocardial infarction or coronary death). In a model containing standard coronary risk factors, treadmill aerobic capacity and ST segment response to exercise, age, gender, serum cholesterol level, aerobic capacity and ST-segment response, but not HR recovery-2' were independent predictors of CE. These findings cast doubt on the value of HR recovery as a coronary risk factor in subjects without apparent heart disease. B. To determine whether the apoliprotein E4 allele (apo E4) is associated with an increased risk of coronary events (CE) i.e. angina pectoris, myocardial infarction or sudden death, we determined apoE genotype in 731 asymptomatic Baltimore Longitudinal Study of Aging (BLSA) volunteers followed for a mean period of 17 years. Although the 200 subjects with at least one apo E4 allele and the 531 without apo E4 had similar levels of conventional coronary risk factors, CE developed in 21% of apo E4 subjects vs. 13% in the other group. On multivariate Cox analysis, the apo E4 allele was a strong independent predictor of events in men(RR=2.9,p<0.0001), but not in women (RR=0.9,p=ns). C. We examined the relative contributions of leisure time physical activity (LTPA) and aerobic fitness (peak VO2) during treadmill exercise to development of CE in 689 clinically healthy men 18-93 years old. Over a mean follow-up of 13.4 yrs, a CE occurred in 63 (9%). In multivariate Cox model, higher peak VO2 was protective against CE, both in men <65 years [RR=0.53/SD] and those >65 years [RR=0.61/SD]. In contrast, high intensity LTPA (greater than or equal to 6METs)had an independent protective effect in older but not younger men. Thus, strategies to increase LTPA may be more effective in reducing the CE incidence in older than younger men.

工作摘要：我们的实验室使用多种方法来研究表面健康受试者中冠心病的潜在预测因子。答：在有症状和无症状人群中，停止最大跑步机运动后心率 (HR) 下降的速率已被提议作为未来冠状动脉事件 (CE) 的独立预测因子。为了在表面上健康的受试者中检验这一假设，我们确定了超过 1000 名巴尔的摩老龄化纵向研究 (BLSA) 志愿者的峰值运动与运动后 2 分钟之间的心率下降 (HR 恢复-2') 之间的关系以及后续发展CE（心绞痛、心肌梗塞或冠心病死亡）。在包含标准冠状动脉危险因素的模型中，跑步机有氧能力和 ST 段对运动的反应、年龄、性别、血清胆固醇水平、有氧能力和 ST 段反应（但不是 HR recovery-2'）是 CE 的独立预测因子。这些发现对心率恢复作为无明显心脏病受试者的冠状动脉危险因素的价值提出了质疑。 B. 为了确定载脂蛋白 E4 等位基因 (apo E4) 是否与冠状动脉事件 (CE)（即心绞痛、心肌梗塞或猝死）风险增加相关，我们在 731 名无症状巴尔的摩纵向衰老研究 (BLSA) 中确定了 apoE 基因型志愿者的平均随访时间为 17 年。尽管 200 名至少具有一个 apo E4 等位基因的受试者和 531 名不具有 apo E4 等位基因的受试者具有相似的传统冠状动脉危险因素水平，但在 apo E4 受试者中，有 21% 的受试者出现 CE，而另一组受试者中则为 13%。在多变量 Cox 分析中，apo E4 等位基因是男性事件的强大独立预测因子（RR=2.9，p<0.0001），但在女性中则不然（RR=0.9，p=ns）。 C. 我们对 689 名 18-93 岁临床健康男性进行了跑步机锻炼期间休闲时间体力活动 (LTPA) 和有氧健身（峰值摄氧量）对 CE 发展的相对贡献。在平均 13.4 年的随访中，63 例 (9%) 发生了 CE。在多变量 Cox 模型中，无论是 <65 岁的男性 [RR=0.53/SD] 还是 >65 岁的男性 [RR=0.61/SD]，较高的峰值 VO2 对 CE 有保护作用。相比之下，高强度 LTPA（大于或等于 6METs）对老年男性具有独立的保护作用，但对年轻男性则没有。因此，增加 LTPA 的策略可能比年轻男性更有效地降低老年男性的 CE 发生率。