Fractional flow reserve and intravascular ultrasound in the assessment of moderate coronary lesions: a comparative study

Abstract

Objective The aim of this study was to assess intermediate coronary lesions as detected by visual estimation in coronary angiography using two invasive modalities: fractional flow reserve (FFR) and intravascular ultrasound. Background The significance of coronary artery stenosis of intermediate severity can be difficult to determine. The management of intermediate coronary lesions, defined by a diameter stenosis of more than 40% to less than 70%, continues to be a therapeutic dilemma for cardiologists. The two-dimensional representation of the arterial lesion provided by angiography is limited in distinguishing intermediate lesions that require stenting from those that simply need appropriate medical therapy. Patients and methods Thirty patients with intermediate coronary stenosis on coronary angiography were subjected to a noninvasive stress test, either exercise myocardial perfusion imaging or stress echocardiography, and the results were compared with those of intravascular ultrasound and FFR. Results In this study, 30 patients were subjected to FFR measurement. Twelve of 14 patients had an FFR of less than 0.80; reversible ischemia was detected on the stress test. In contrast, only two of 16 patients with an FFR of more than 0.80 had a negative stress test for reversible myocardial ischemia. FFR value has a sensitivity and a specificity of 85.7 and 87.5%, respectively, in predicting the results of a noninvasive stress test, with a positive predictive value and negative predictive value of 85.7 and 87.5%, respectively, with an accuracy of 86.7%. It is also showed that the best cutoff value for the minimal luminal area that is concordant with FFR values is less than 4.5 mm 2 , which has a sensitivity and a specificity of 57.1 and 56.3%, respectively, and positive predictive value of 53.3% and negative predictive value of 60%. Conclusion In patients with coronary stenosis of intermediate severity, FFR appears to be a useful index for assessment of the functional severity of coronary artery stenosis in comparison with a noninvasive stress test and can be used as a guide before coronary revascularization.