Effect of exercise training on myocardial blood flow in patients with stable coronary artery disease.
BACKGROUND
The mechanisms by which exercise training benefits patients with coronary artery disease (CAD) are unclear but may include improved myocardial circulation. The aim of this study was to investigate the effect of exercise training on myocardial blood flow (MBF) and coronary flow reserve (CFR) in patients with stable CAD.


METHODS
Twelve patients with documented CAD and ischemic ST-segment depression during exercise testing were randomized to exercise training (n = 7) or sedentary life style (control; n = 5) and underwent rubidium-82 positron emission tomography pre- and postintervention. Global left ventricle MBF and regional MBF in 17 left ventricular segments were calculated. Segments with <75% uptake (2 SD below normal) on stress uptake images were defined as abnormal.


RESULTS
Exercise training increased global CFR by 20.8% +/- 27.9% versus control (10.5 +/- 24.1%, P = .0001). In normal segments (exercise training: n = 91; control: n = 46), exercise training did not change resting MBF (-14.1% +/- 16.3% vs -8.8% +/- 15.6%) and hyperemic MBF (-1.93% +/- 19.1% vs 2.86% +/- 20.5%, P = NS) and increased in CFR compared to control (17.0% +/- 25.5% vs 11.3% +/- 23.5%, P = .01). In abnormal segments, the change in resting MBF was not significantly different (-12.6% +/- 18.5% exercise [28 segments] vs -2.9% +/- 18.0% control [39 segments], P = NS). A significant increase was seen in hyperemic MBF with exercise (12.5% +/- 22.1% vs 2.6% +/- 16.3%, P = .02) and CFR (32.8% +/- 32.3% vs 9.5% +/- 24.8%, P = .001).


CONCLUSIONS
Exercise training increased CFR in normal and diseased segments, and increased hyperemic flow in diseased segments. These data provide preliminary evidence in support of a favorable effect of exercise training on blood flow to ischemic myocardium.
Yoshinaga
Keiichiro
K
Division of Cardiology, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
Beanlands
Rob S B
RS
Dekemp
Robert A
RA
Lortie
Mireille
M
Morin
Jason
J
Aung
May
M
McKelvie
Robert
R
Davies
Richard F
RF
D003324:Coronary Artery Disease / Q000503:physiopathology*; D003326:Coronary Circulation; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged