Morise A P
Section of Cardiology, Department of Medicine, West Virginia University School of Medicine, Morgantown 26506, USA.
Chest. 2000 Aug;118(2):535-41. doi: 10.1378/chest.118.2.535.
Recently published American College of Cardiology (ACC)/American Heart Association (AHA) guidelines state that patients with suspected coronary disease and an intermediate pretest probability are appropriate candidates for exercise ECG, while those with low or high pretest probability are not.
From 5,103 consecutive patients with symptoms of suspected coronary disease, we evaluated 872 patients who underwent coronary angiography following exercise ECG. Differences in test performance were determined using receiver operating characteristic curve area analysis. A score using age, gender, symptoms, and risk factors was used to classify patients into low, intermediate, and high pretest probability groups.
When patients with inadequate exercise tests were excluded, overall sensitivity and specificity were 70% and 66%, respectively. Only the intermediate pretest probability group demonstrated significant incremental value: pretest vs posttest intermediate, 70 +/- 3 vs 79 +/- 3 (p < 0.0001); low, 71 +/- 6 vs 76 +/- 7 (p = 0.39); and high, 69 +/- 8 vs 75 +/- 7 (p = 0.12). From the low- to the high-probability groups, there was a progressive increase in positive predictive value (21%, 62%, and 92%) and decrease in negative predictive value (94%, 72%, and 28%), respectively. The frequencies of abnormal exercise ECGs were lower in the unselected groups compared with the angiography groups (low, 13% vs 36%; intermediate, 22% vs 53%; high, 36% vs 63%).
Based on the information added by exercise testing to clinical data, these results confirm the ACC/AHA guideline assignments for test selection. However, despite these guidelines, patients with a low pretest probability can be selected for exercise testing with the knowledge that a positive result is infrequent and a negative result carries a very high negative predictive value. Intermediate-probability patients on average carry a significant false-negative rate, suggesting that exercise ECG alone may not be a sufficient screening test in all intermediate-probability patients. Because of poor negative predictive value and a large percentage of negative tests, high-probability patients should undergo coronary angiography as the initial strategy, unless the goal of exercise testing is to assess prognosis.
美国心脏病学会（ACC）/美国心脏协会（AHA）最近发布的指南指出，疑似冠心病且预检概率为中等的患者适合进行运动心电图检查，而预检概率低或高的患者则不适合。
从5103例连续出现疑似冠心病症状的患者中，我们评估了872例在运动心电图检查后接受冠状动脉造影的患者。使用受试者工作特征曲线面积分析来确定检查性能的差异。使用年龄、性别、症状和危险因素的评分将患者分为低、中、高预检概率组。
排除运动试验不充分的患者后，总体敏感性和特异性分别为70%和66%。只有预检概率为中等的组显示出显著的增加值：预检与检查后中等概率组，70±3对79±3（p<0.0001）；低概率组，71±6对76±7（p=0.39）；高概率组，69±8对75±7（p=0.12）。从低概率组到高概率组，阳性预测值逐渐增加（21%、62%和92%），阴性预测值逐渐降低（94%、72%和28%）。与冠状动脉造影组相比，未选择组中运动心电图异常的频率较低（低概率组，13%对36%；中等概率组，22%对53%；高概率组，36%对63%）。
基于运动试验添加到临床数据中的信息，这些结果证实了ACC/AHA指南中关于检查选择的规定。然而，尽管有这些指南，预检概率低的患者可以选择进行运动试验，因为要知道阳性结果很少见，阴性结果具有很高的阴性预测值。中等概率的患者平均有显著的假阴性率，这表明仅运动心电图可能不是所有中等概率患者的充分筛查试验。由于阴性预测值差且阴性试验比例大，高概率患者应将冠状动脉造影作为初始策略，除非运动试验的目的是评估预后。
