- Coronary angiography alone to assess CAD is fraught with subjectivity
- Fractional flow reserve (FFR) has become the standard to assess/quantify obstructive CAD; it determines the myocardial flow in the presence of stenosis identifying the lesion responsible for ischemia
- FFR assesses focal stenosis, but does not consider diffuse atherosclerotic narrowing or microcirculatory dysfunction as contributors of ischemic heart disease
- An index of microcirculatory resistance (IMR) can be concomitantly measured with FFR during cardiac catheterization to specifically evaluate the microvasculature
- Coronary flow reserve (CFR) was the 1st proposed method for assessment of intermediate coronary lesion, but proved suboptimal because of its variability especially in patients with microvascular dysfunction (diabetes, prior MI, etc.)
- Utilization of FFR, IMR, and CFR together support the existence of differentiated patterns of ischemic heart disease & may help to determine future ischemic events
References
Echavarria-Pinto M, Escaned J, Macias E, et al. Disturbed Coronary Hemodynamics in Vessels With Intermediate Stenosis Evaluated With Fractional Flow Reserve: A Combined Analysis of Epicardial and Microcirculatory Involvement in Ischemic Heart Disease. Circulation Volume 128(24), 17 December 2013, p 2557–2566
