The diagnostic value of measuring the momentary blood flow reserve versus non-invasive methods to detect myocardial ischemia in assessing the functional significance of borderline coronary artery stenoses

Abstract

Aim. To estimate the diagnostic value of measuring the momentary blood flow reserve (MBFR) versus the surrogate non-invasive standard (SNS) for myocardial ischemia verification (MIV) (a combination of stress echocardiography and single-photon emission computed tomography). Subjects and methods. The investigation enrolled 50 patients with stable angina in the presence of chronic coronary heart disease (CHD) or suspected CHD, in whom coronary angiography (CA) revealed borderline coronary stenoses (50—70% lumen diameters). The examination algorithm had two options. In one option, when included in the study, patients had already CA results not older than 1 month, and MBFR was measured 4—7 days after non-invasive stress tests. In the other option, MBFR in the area of borderline coronary artery stenosis was measured simultaneously with CA; and the noninvasive stress tests were carried out in the following week. A total of 74 coronary stenoses were examined. Results. SNS for MIV was positive in 14 (28%) patients. When comparing with the non-invasive methods of myocardial ischemia verification, the area under the ROC curve for MBFR was 0.961±0.019 (95% confidence interval, 0.888—0.992). The optimal cut-point was 0.92, which is corresponded by a sensitivity of 100% and a specificity of 84%. Conclusion. When compared with SNS for MIV, the method for measuring MBFR has a high diagnostic accuracy.

Keywords

• borderline coronary stenoses
• momentary blood flow reserve
• stress echocardiography
• single-photon emission computed tomography of the myocardium