Zaid Gh, Tanchilevitch A, Rivlin E, Gropper R, Rosenschein U, Lanir A, Goldhammer E
Department of Cardiology and Cardiac Rehabilitation, Bnai-Zion Medical Center and the Faculty of Medicine, Technion Institute of Technology, Haifa, Israel.
Int J Cardiol. 2007 Apr 25;117(2):157-64. doi: 10.1016/j.ijcard.2006.06.013. Epub 2006 Sep 25.
To determine whether serum B-type natriuretic peptide measured at rest and peak exercise and DeltaBNP contribute to the predictive value and diagnostic accuracy of exercise test in the diagnosis of myocardial ischemia.
Ventricular myocytes release BNP in response to increased wall stress that occurs in acute ischemia. During exercise testing, transient myocardial ischemia could also cause acute myocardial stress and changes in circulating BNP.
BNP was measured before and immediately after exercise testing with radionuclide imaging in 203 consecutive subjects referred for chest pain evaluation. Tested subjects were classified as ischemic and non-ischemic based on exercise results, and no ischemia, mild-moderate, and severe ischemia according to perfusion scan results. A logistic regression model, constructed of an ROC and an AUC (area under the curve), was used.
Ischemic ECG changes (> or =1 mm, horizontal S-T shift) were detected in the treadmill exercise test in 127 subjects (62.6%), and 76 (37.4%) had neither ST segment shift nor chest pain. Baseline BNP was higher in the ischemic group compared to the non-ischemic group (p=0.044); peak BNP was also higher in the ischemic group (p=0.025), as was DeltaBNP (p=0.0126). Of these 127 subjects, 106 (52% of all) had abnormal perfusion scan results. In the ischemic group, the median baseline, peak exercise BNP, and DeltaBNP values from baseline to peak were higher than in the non-ischemic group. In the severe ischemic group these variables were approximately three-fold higher than in the mild-moderate ischemic group (p<0.0001 for baseline; p<0.0001 for peak; and p<0.0001 for DeltaBNP). Rest, peak exercise, and DeltaBNP values were significantly higher in patients with previous myocardial infarction (p<0.001) and in patients treated with beta blockers; peak exercise BNP was higher in hypertensives and diabetics (p<0.05). The ROC convergence model showed that the AUC for peak-exercise BNP was best able to discriminate and predict severe ischemia and no ischemia, while DeltaBNP from rest to peak exercise discriminated best between mild-moderate and severe ischemia.
Peak exercise BNP and DeltaBNP improved the sensitivity, specificity, positive likelihood ratio, predictive value, and diagnostic accuracy of severe ischemia detection during an exercise test. The contribution of BNP determination during exercise was, however, less impressive than previously reported by others.
确定静息和运动峰值时测定的血清B型利钠肽（BNP）以及BNP差值（DeltaBNP）是否有助于运动试验对心肌缺血诊断的预测价值和诊断准确性。
心室肌细胞在急性缺血时因壁应力增加而释放BNP。在运动试验期间，短暂性心肌缺血也可导致急性心肌应激和循环BNP的变化。
对203例因胸痛前来评估的连续受试者在运动试验前及运动试验后立即进行放射性核素成像检查时测定BNP。根据运动结果将受试对象分为缺血性和非缺血性，根据灌注扫描结果分为无缺血、轻 - 中度缺血和重度缺血。使用由ROC（曲线下面积）和AUC构建的逻辑回归模型。
在跑步机运动试验中，127例受试者（62.6%）检测到缺血性心电图改变（≥1mm，水平S-T段移位），76例（37.4%）既无ST段移位也无胸痛。缺血组的基线BNP高于非缺血组（p = 0.044）；缺血组的运动峰值BNP也较高（p = 0.025），DeltaBNP也是如此（p = 0.0126）。在这127例受试者中，106例（占全部的52%）灌注扫描结果异常。在缺血组中，基线、运动峰值BNP以及从基线到峰值的DeltaBNP中位数高于非缺血组。在重度缺血组中，这些变量比轻 - 中度缺血组高约三倍（基线p<0.0001；峰值p<0.0001；DeltaBNP p<0.0001）。既往有心肌梗死的患者（p<0.001）以及接受β受体阻滞剂治疗的患者静息、运动峰值和DeltaBNP值显著更高；高血压患者和糖尿病患者的运动峰值BNP更高（p<0.05）。ROC收敛模型显示，运动峰值BNP的AUC最能区分和预测重度缺血和无缺血，而静息到运动峰值的DeltaBNP在区分轻 - 中度和重度缺血方面表现最佳。
运动峰值BNP和DeltaBNP提高了运动试验期间重度缺血检测的敏感性、特异性、阳性似然比、预测价值和诊断准确性。然而，运动期间BNP测定的作用不如其他人先前报道的那么显著。
