Abstract 12519: Age Impacts the Interpretation of Myocardial Blood Flow Values in Cardiac PET/CT
Introduction: Quantitative myocardial blood flow (MBF) obtained via Rb82 PET/CT using regadenoson provides the ability to assess ischemia through analysis of stress MBF and coronary flow reserve (CFR), the augmentation of flow expressed as a stress/rest ratio. It is unknown to what extent, if any, age-related changes in arteries (i.e. arterial stiffening, atherosclerosis) impact MBF and, thus, the interpretation of ischemia.
Hypothesis: MBF values change as a function of age and impact PET interpretation.
Methods: Patients who underwent PET/CT from May 2013 to April 2015 with normal perfusion images and no history of PCI or CABG were included (n=3329, 1720 women, 1498 men). Rest MBF, stress MBF, and CFR) (mL/min/g) were recorded in all vessels separated by gender and by age <60 or ≥60. Analysis was conducted on individual vessels and global estimates were calculated averaging all vessels. Estimated average median differences between age <60 and ≥60 were adjusted for traditional cardiovascular risk factors (BMI, smoking, diabetes, hypertension, hyperlipidemia, family history).
Results: Effects of Age on Global MBF Adjusted for Traditional Risk Factors
Conclusions: In patients ≥60 years of age with normal perfusion imaging, rest MBF increases, stress MBF decreases, and the resultant CFR is decreased, all statistically significant. This may reflect a higher fixed level of vasodilation in older vessels at rest and a more limited ability to vasodilate with stress independent of other CV risk factors. Given the increasing use of PET/CT for ischemia assessment, it is important to recognize expected MBF changes with age to decrease false positive studies and unwarranted invasive testing.
Author Disclosures: H.E. Raasch: None. R.O. McCubrey: None. J. Ethington: None. S. Mason: None. V.T. Le: None. R. Dhar: None. K.G. Meredith: None. J.L. Anderson: None.
- © 2015 by American Heart Association, Inc.