CFR measurement is a key clinical application and diagnostic tool that assists in: 5
- functional assessment of intermediate stenosis
- detection of critical stenosis and specific coronary artery stenosis
- localization monitoring of coronary flow after revascularization procedures
- quantifying post infarct blood flow
- assessing coronary graft patency
Including noninvasive quantitative assessment of coronary vasodilator function with positron emission tomography is a powerful, independent predictor of cardiac mortality in patients with known or suspected coronary artery disease and provides meaningful incremental risk stratification over clinical and gated myocardial perfusion imaging variables. 6 The accompanying table demonstrates the risk reclassification after coronary flow imaging is added to the qualitative assessment.
The calculation of myocardial blood flow has some variability across scanner manufacturers, radiopharmaceuticals and software programs. The calculation of coronary flow reserve is considerably more consistent, with similar relationships between coronary flow reserve and cardiac mortality, regardless of technique used. The accompanying image demonstrates the increased risk in cardiac mortality with a decreasing flow reserve. 7
3. Gould KL. Assessing progression or regression of CAD: the role of perfusion imaging. Journal of Nuclear Cardiology. 2005 Nov 1;12(6):625-38.
5. Johnson NP, Gould KL. Physiological basis for angina and ST-segment change: PET-verified thresholds of quantitative stress myocardial perfusion and coronary flow reserve. JACC: Cardiovascular Imaging. 2011 Sep 30;4(9):990-8.
6. Murthy VL, Naya M, Foster CR, Hainer J, Gaber M, Di Carli G, et al. Improved Cardiac Risk Assessment With Noninvasive Measures of Coronary Flow ReserveClinical Perspective. Circulation. 2011 Nov 15;124(20):2215-24.
7. Murthy VL, Lee BC, Sitek A, Naya M, Moody J, Polavarapu V, et al. Comparison and prognostic validation of multiple methods of quantification of myocardial blood flow with 82Rb PET. J Nucl Med 2014;55:1952-8.