Impaired coronary flow reserve in patients with metabolic syndrome.
BACKGROUND
Metabolic syndrome (MetS) is a strong predictor of cardiovascular events. Coronary flow reserve (CFR), as determined by transthoracic echocardiography, is an indicator of microvascular function. In this study, we sought to determine whether CFR is impaired in patients with MetS without clinical coronary heart disease.


METHODS
Thirty-three patients with MetS (mean age, 67+/-8 years) and 35 age- and sex-matched controls were studied prospectively. Transthoracic two-dimensional and Doppler echocardiography was performed on all patients. Baseline and hyperemic (after dipyridamole infusion) coronary flow rates were measured using pulsed Doppler echocardiography. CFR was calculated as the ratio of hyperemic to baseline diastolic peak velocities.


RESULTS
There was no difference with regard to baseline systolic and diastolic coronary flow rates in patients with MetS compared with control subjects (19.9+/-3.1cm/s vs. 19.7+/-2.9cm/s, P>.05; and 27.7+/-4.2cm/s vs. 27.1+/-3.6cm/s, P>.05, respectively). Hyperemic diastolic flow and CFR were significantly lower in patients with MetS than in controls (61.7+/-9.4cm/s vs. 70.2+/-9.2cm/s, P<.0001; and 2.2+/-0.5 vs. 2.6+/-0.4, P=.001, respectively). In a logistic regression analysis that included age, sex, body mass index, hypertension, and dyslipidemia and MetS, MetS was the only predictor of a CFR<2.5 (P=.007, OR=6.1, 95% CI: 1.6-23.3).


CONCLUSIONS
In conclusion, CFR is impaired in patients with MetS suggesting that coronary microvascular dysfunction, an early finding of atherosclerosis, is present in this patient population. Metabolic syndrome is associated with a CFR<2.5.
Pirat
Bahar
B
Baskent University Faculty of Medicine, Department of Cardiology, Ankara, Turkey. baharp@baskent-ank.edu.tr
Bozbas
Huseyin
H
Simsek
Vahide
V
Yildirir
Aylin
A
Sade
L Elif
LE
Gursoy
Yusuf
Y
Altin
Cihan
C
Atar
Ilyas
I
Muderrisoglu
Haldun
H
D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D016022:Case-Control Studies; D015331:Cohort Studies; D003326:Coronary Circulation / Q000502:physiology*; D003327:Coronary Disease / Q000209:etiology; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D012307:Risk Factors