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Updated: Jun 21, 2025
High-Resolution Cardiac Positron Emission Tomography/Computed Tomography for Small Animals
Published on: December 16, 2022
Age- and Sex-Specific Myocardial Blood Flow Values in Patients Without Coronary Atherosclerosis on Rb-82 PET
Brett W Sperry1,2, Mark P Metzinger1,2, Ali O Ibrahim2
1Saint Luke's Mid America Heart Institute, Kansas City, MO (B.W.S., M.P.M., R.C.T., A.I.M.G., T.M.B.).
Insights
Myocardial blood flow reserve (MBFR) is lower in older individuals and women. Age- and sex-specific MBFR ranges are crucial for cardiovascular risk assessment and guiding treatment decisions.
Area of Science:
- Cardiovascular Imaging
- Nuclear Cardiology
- Physiology
Background:
- Quantitative myocardial blood flow (MBF) assessed by positron-emission tomography (PET) is vital for evaluating coronary circulation health.
- Myocardial blood flow reserve (MBFR) augmentation is linked to reduced cardiovascular events and mortality.
- Established age-specific MBFR ranges in healthy individuals are lacking.
Purpose of the Study:
- To determine the influence of age and sex on MBF and MBFR.
- To establish age- and sex-specific reference ranges for MBFR in patients without coronary artery disease.
Main Methods:
- Retrospective analysis of PET myocardial perfusion imaging studies (2012-2022).
- Inclusion criteria: summed stress score 0, coronary calcium score 0, LVEF ≥50%. Exclusion criteria: known CAD, prior interventions, diabetes, transplants, cirrhosis, advanced CKD.
- MBF calculated using a net retention model; quantile regression used to predict MBF.
Main Results:
- 2789 patients included (59.9±13.0 years, 76.4% female).
- Median MBFR was 2.31 (1.96-2.74).
- Males had higher MBFR than females, especially younger individuals, with the gap narrowing with age. MBFR decreased with age in both sexes.
Conclusions:
- MBFR is higher in younger males than females and declines with age.
- Age- and sex-specific MBFR values are important for cardiovascular risk stratification.
- Further research is warranted to validate the clinical utility of age- and sex-specific MBFR.
Background:
Quantitative myocardial blood flow (MBF) on positron-emission tomography myocardial perfusion imaging is a measure of the overall health of the coronary circulation. The ability to adequately augment blood flow, measured by myocardial blood flow reserve (MBFR), is associated with lower major adverse cardiovascular events and all-cause mortality. The age-specific ranges of MBFR in patients without demonstrable coronary artery disease have not been well established. We aimed to determine the effect of age and sex on MBF in a cohort of patients without demonstrable coronary artery disease.
Methods:
Patients who underwent positron-emission tomography myocardial perfusion imaging studies from 2012 to 2022 on positron-emission tomography/computed tomography cameras were included if the summed stress score was 0, the coronary calcium score was 0, and the left ventricular ejection fraction was ≥50%. Those with known coronary artery disease, prior history of coronary intervention, diabetes, heart/kidney/liver transplant, cirrhosis, or chronic kidney disease stage IV+ were excluded. MBF was calculated using a net retention model (ImagenQ, Cardiovascular Imaging Technologies, Kansas City), and quantile regression models were developed to predict MBF.
Results:
Among 2789 patients (age 59.9±13.0 years, 76.4% females), median rest MBF was 0.73 (0.60-0.91) mL/min·g, stress MBF was 1.72 (1.41-2.10) mL/min·g, and MBFR was 2.31 (1.96-2.74). Across all ages, males augmented MBF in response to vasodilator stress to a greater degree than females but achieved lower absolute stress MBF. Younger males in particular achieved a higher MBFR than their female counterparts, and this gap narrowed with increasing age. Predicted MBFR for a 20-year-old male was 3.18 and female was 2.50, while predicted MBFR for an 80-year-old male was 2.17 and female was 2.02.
Conclusions:
In patients without demonstrable coronary artery disease, MBFR is higher in younger males than younger females and decreases with age in both sexes. Age- and sex-specific MBFR may be important in risk prediction and guidance for revascularization and warrant further study.
