Quyyumi A A, Panza J A, Diodati J G, Callahan T S, Bonow R O, Epstein S E
Cardiology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892.
J Am Coll Cardiol. 1993 Mar 1;21(3):700-8. doi: 10.1016/0735-1097(93)90103-8.
The purpose of this study was to determine the incidence and prognostic importance of myocardial ischemia detected by ambulatory monitoring in low risk, medically managed patients with coronary artery disease.
Previous studies have demonstrated that certain high risk subsets of patients with coronary artery disease have improved survival with revascularization. The remaining low risk medically managed patients may still have episodes of silent ischemia during daily living, but the frequency and prognostic implications of such episodes in this group are unknown.
We prospectively studied the incidence and prognostic significance of ST segment changes recorded during daily activities in 116 asymptomatic or mildly symptomatic low risk patients with native coronary artery disease who were followed up for 29 +/- 13 months. Low risk patients were selected after excluding patients with 1) left main disease; 2) three-vessel coronary artery disease and left ventricular dysfunction at rest; 3) three-vessel disease and inducible ischemia during exercise; and 4) two-vessel disease, left ventricular dysfunction and inducible ischemia.
Forty-five patients (39%) had transient episodes of ST segment depression during 48-h electrocardiographic (ECG) monitoring (total 217 episodes, lasting 7,223 min, 82% of episodes silent). There were eight acute cardiac events (seven myocardial infarctions, one episode of unstable angina) and nine patients underwent elective revascularization. Seven of the eight acute events occurred in patients without silent ischemia during monitoring. Kaplan-Meier survival analysis revealed no significant differences in event-free survival from either acute or total events in subgroups with or without silent ischemia during ambulatory ECG monitoring. None of the clinical, treadmill exercise, radionuclide ventriculographic or cardiac catheterization variables were predictive of outcome by Cox multivariate proportional hazard function analysis. Analysis of coronary arteriograms before and after acute cardiac events revealed that in five of the six patients studied, acute occlusion occurred in a coronary artery different from the artery with the severest stenosis on initial angiography.
In patients categorized as at low risk on the basis of the results of cardiac catheterization and stress testing, silent myocardial ischemia during daily life was not uncommon, and its presence failed to predict future coronary events.
本研究旨在确定动态监测在低风险、药物治疗的冠心病患者中检测到的心肌缺血的发生率及其预后重要性。
既往研究表明，某些高危亚组的冠心病患者接受血运重建后生存率有所提高。其余低风险、接受药物治疗的患者在日常生活中仍可能有静息性缺血发作，但该组此类发作的频率及其预后意义尚不清楚。
我们前瞻性地研究了116例无症状或症状轻微的低风险、原发性冠心病患者在日常活动中记录的ST段变化的发生率及其预后意义，这些患者随访了29±13个月。低风险患者是在排除以下患者后选择的：1）左主干病变；2）三支冠状动脉病变且静息时左心室功能不全；3）三支病变且运动时诱发缺血；4）两支病变、左心室功能不全且诱发缺血。
45例患者（39%）在48小时心电图（ECG）监测期间有ST段压低的短暂发作（共217次发作，持续7223分钟，82%的发作无症状）。有8例急性心脏事件（7例心肌梗死，1例不稳定型心绞痛发作），9例患者接受了择期血运重建。8例急性事件中有7例发生在监测期间无静息性缺血的患者中。Kaplan-Meier生存分析显示，动态心电图监测期间有无静息性缺血的亚组在无急性或总事件的生存方面无显著差异。通过Cox多变量比例风险函数分析，没有一个临床、平板运动、放射性核素心室造影或心脏导管检查变量能够预测预后。对急性心脏事件前后的冠状动脉造影分析显示，在研究的6例患者中的5例中，急性闭塞发生在与初始血管造影时狭窄最严重的动脉不同的冠状动脉中。
在根据心脏导管检查和负荷试验结果分类为低风险的患者中，日常生活中的静息性心肌缺血并不少见，但其存在并不能预测未来的冠状动脉事件。
