British Heart Foundation Center of Excellence and National Institute for Health Research Biomedical Research Center at the School of Cardiovascular Medicine and Sciences, King's College London, London, United Kingdom. Electronic address: https://twitter.com/AishSinha1.
British Heart Foundation Center of Excellence and National Institute for Health Research Biomedical Research Center at the School of Cardiovascular Medicine and Sciences, King's College London, London, United Kingdom.
J Am Coll Cardiol. 2024 Jan 16;83(2):291-299. doi: 10.1016/j.jacc.2023.10.034.
Exercise electrocardiographic stress testing (EST) has historically been validated against the demonstration of obstructive coronary artery disease. However, myocardial ischemia can occur because of coronary microvascular dysfunction (CMD) in the absence of obstructive coronary artery disease.
The aim of this study was to assess the specificity of EST to detect an ischemic substrate against the reference standard of coronary endothelium-independent and endothelium-dependent microvascular function in patients with angina with nonobstructive coronary arteries (ANOCA).
Patients with ANOCA underwent invasive coronary physiological assessment using adenosine and acetylcholine. CMD was defined as impaired endothelium-independent and/or endothelium-dependent function. EST was performed using a standard Bruce treadmill protocol, with ischemia defined as the appearance of ≥0.1-mV ST-segment depression 80 ms from the J-point on electrocardiography. The study was powered to detect specificity of ≥91%.
A total of 102 patients were enrolled (65% women, mean age 60 ± 8 years). Thirty-two patients developed ischemia (ischemic group) during EST, whereas 70 patients did not (nonischemic group); both groups were phenotypically similar. Ischemia during EST was 100% specific for CMD. Acetylcholine flow reserve was the strongest predictor of ischemia during exercise. Using endothelium-independent and endothelium-dependent microvascular dysfunction as the reference standard, the false positive rate of EST dropped to 0%.
In patients with ANOCA, ischemia on EST was highly specific of an underlying ischemic substrate. These findings challenge the traditional belief that EST has a high false positive rate.
运动心电图应激测试（EST）历来是通过显示阻塞性冠状动脉疾病来验证的。然而，在没有阻塞性冠状动脉疾病的情况下，也可能发生心肌缺血，因为存在冠状动脉微血管功能障碍（CMD）。
本研究旨在评估 EST 在检测心绞痛伴非阻塞性冠状动脉（ANOCA）患者缺血性底物方面的特异性，该特异性以冠状动脉内皮非依赖性和内皮依赖性微血管功能的参考标准为基础。
ANOCA 患者接受腺苷和乙酰胆碱的有创冠状动脉生理评估。CMD 定义为内皮非依赖性和/或内皮依赖性功能受损。EST 使用标准的 Bruce 跑步机方案进行，当心电图上 J 点后 80ms 出现≥0.1mV 的 ST 段压低时，定义为缺血。该研究的目的是检测特异性≥91%。
共纳入 102 例患者（65%为女性，平均年龄 60±8 岁）。32 例患者在 EST 期间出现缺血（缺血组），而 70 例患者未出现缺血（非缺血组）；两组在表型上相似。EST 期间出现缺血对 CMD 具有 100%的特异性。乙酰胆碱流量储备是运动时出现缺血的最强预测因子。当将内皮非依赖性和内皮依赖性微血管功能障碍作为参考标准时，EST 的假阳性率降至 0%。
在 ANOCA 患者中，EST 上的缺血与潜在的缺血性底物高度相关。这些发现挑战了 EST 具有高假阳性率的传统观念。
