Influence of age and hemodynamics on myocardial blood flow and flow reserve.

Abstract

Aging does not alter significantly dipyridamole-induced hyperemic flows; although coronary vascular resistance after dipyridamole was somewhat increased in older subjects. The gradual decline of the myocardial blood flow reserve correlates with an age-related increase of baseline myocardial work and blood flow. These findings suggest that the reduced flow reserve with age is primarily due to increased cardiac work and blood flow at rest rather than to an abnormal vasodilator capacity.

Clinical Quantification of Myocardial Blood Flow Using PET: Joint Position Paper of the SNMMI Cardiovascular Council and the ASNC

“…[65][66][67][68][69][70][71] Apart from methodologic differences in radiotracer characteristics, tracer kinetic models, and image analysis that may introduce some variations between different studies, the variability of the reported resting MBF values may be attributed in part to differences in myocardial workload and thus the myocardial oxygen demand of the left ventricle. 66,67,[72][73][74] Sex and genetic variations, including mitochondrial function, are also important determinants contributing to the variability in resting MBF values. 75 MBF at rest and during some forms of stress is physiologically coupled with myocardial oxygen demand and thus correlates with indices of myocardial workload (e.g., rate-pressure product, defined as the product of systolic blood pressure and heart rate).…”

“…[76][77][78] Consequently, resting MBF is commonly higher in patients with higher arterial blood pressure or heart rate. 67,70,79,80 Age-related increases in resting MBF can be explained by rate-pressure product correction of increased systolic blood pressures. 67,81 Most of the reported PET-determined resting MBF values have been higher in women than in men.…”

“…67,70,79,80 Age-related increases in resting MBF can be explained by rate-pressure product correction of increased systolic blood pressures. 67,81 Most of the reported PET-determined resting MBF values have been higher in women than in men. 66,68,82,83 Although the causes of this sex difference are not completely defined, hormonal effects on coronary circulatory function in women with CAD, and sex-dependent lipid profile changes, may be important contributors.…”

“…4 However, patients with heart failure are also at increased risk of complications from invasive coronary angiography. Consequently, the excellent negative predictive value of preserved MFR may be of particular value in excluding severe multivessel CAD in patients with 67 18 31 ± 9 Dipyridamole 0.76 ± 0.25 3.00 ± 0.80 4.1 ± 0.90 Czernin et al 38 11 27 ± 7 Dipyridamole NR 2.13 ± 0.28 NR Nagamachi et al 21 30 33 ± 15 Dipyridamole/ adenosine 0.62 ± 0.14 2.01 ± 0.39 NR Yokoyama et al 163 Furthermore, whereas CAD is highly prevalent, the increased risks of invasive investigation and revascularization may shift the balance in some cases toward medical therapy rather than invasive approaches. One unpublished study has demonstrated that MFR assessment with PET may be able to identify patients aged 75 and older with excellent prognosis for survival free of cardiac death.…”

Myocardial Perfusion Is Impaired and Relates to Cardiac Dysfunction in Patients With Atrial Fibrillation Both Before and After Successful Catheter Ablation

“…Baseline MBF is closely related to baseline RPP15; thus, baseline MBF was corrected for baseline RPP using the formula baseline MBF corrected =baseline MBF/(baseline RPP/10 000), to account for differences in cardiac work, as previously described 6. In accordance with previous studies, adenosine‐stress–induced MBF was not corrected because this parameter is grossly independent of RPP 16.…”