Siscovick D S, Ekelund L G, Johnson J L, Truong Y, Adler A
Department of Medicine, Harborview Medical Center, Seattle, Wash.
Arch Intern Med. 1991 Feb;151(2):325-30.
We determined whether the exercise electrocardiogram predicted acute cardiac events during moderate or strenuous physical activity among 3617 asymptomatic, hypercholesterolemic men (age range, 35 to 59 years) who were followed up in the Coronary Primary Prevention Trial. Submaximal exercise test results were obtained at entry and at annual follow-up visits in years 2 through 7. ST-segment depression or elevation (greater than or equal to 1 mm or 10 microV-sec) was considered to be a positive test result. The circumstances that surrounded each nonfatal myocardial infarction and coronary heart disease death were determined through a record review. The cumulative incidence of activity-related acute cardiac events was 2% during a mean follow-up period of 7.4 years. The risk was increased 2.6-fold in the presence of clinically silent, exercise-induced, ST-segment changes at entry (95% confidence interval [Cl], 1.3 to 5.2) after adjustment for 11 other potential risk factors. Of 62 men who experienced an activity-related event, 11 had a positive test result at entry (sensitivity, 18%; 95% Cl, 8 to 27). The specificity of the entry exercise test was 92% (95% Cl, 91 to 93). The sensitivity and specificity were similar when the length of follow-up was restricted to 1 year after testing. For a newly positive test result on a follow-up visit, the sensitivity was 24% (95% Cl, 12 to 36), and the specificity was 85% (95% Cl, 84 to 86); for any positive test result during the study (mean number of tests per subject, 6.2), the sensitivity was 37% (95% Cl, 25 to 49), and the specificity was 79% (95% Cl, 77 to 80). Our findings suggested that the presence of clinically silent, exercise-induced, ischemic ST-segment changes on a submaximal test was associated with an increased risk of activity-related acute cardiac events. However, this test was not sensitive when used to predict the occurrence of activity-related events among asymptomatic, hypercholesterolemic men. For this reason, the utility of the submaximal exercise test to assess the safety of physical activity among asymptomatic men at risk of coronary heart disease is likely to be limited.
我们在冠心病一级预防试验中，对3617名无症状的高胆固醇血症男性（年龄范围35至59岁）进行了随访，以确定运动心电图能否预测中度或剧烈体力活动期间的急性心脏事件。在研究开始时以及第2至7年的年度随访中进行次极量运动试验。ST段压低或抬高（大于或等于1毫米或10微伏-秒）被视为阳性试验结果。通过病历审查确定每次非致命性心肌梗死和冠心病死亡的相关情况。在平均7.4年的随访期内，与活动相关的急性心脏事件的累积发生率为2%。在对其他11个潜在风险因素进行调整后，研究开始时存在临床无症状、运动诱发的ST段改变者，风险增加2.6倍（95%置信区间[Cl]，1.3至5.2）。在62名发生与活动相关事件的男性中，11人在研究开始时试验结果为阳性（敏感性，18%；95%Cl，8至27）。研究开始时运动试验的特异性为92%（95%Cl，91至93）。当随访时间限制在试验后1年时，敏感性和特异性相似。对于随访时新出现的阳性试验结果，敏感性为24%（95%Cl，12至36），特异性为85%（95%Cl，84至86）；对于研究期间任何阳性试验结果（每位受试者平均试验次数为6.2次），敏感性为37%（95%Cl，25至49），特异性为79%（95%Cl，77至80）。我们的研究结果表明，次极量试验中存在临床无症状、运动诱发的缺血性ST段改变与活动相关急性心脏事件风险增加有关。然而，该试验用于预测无症状高胆固醇血症男性中与活动相关事件的发生时并不敏感。因此，次极量运动试验用于评估有冠心病风险的无症状男性体力活动安全性的效用可能有限。
