Metabolic syndrome and diabetes are associated with an increased likelihood of inducible myocardial ischemia among patients with subclinical atherosclerosis.
OBJECTIVE
Coronary artery calcification (CAC) is associated with cardiac events and the likelihood of inducible myocardial ischemia. Because metabolic syndrome contributes to atherosclerosis, we assessed whether it also influences the relationship between CAC levels and myocardial ischemia.


METHODS
We evaluated 1,043 patients without known coronary artery disease (CAD) who underwent stress myocardial perfusion scintigraphy (MPS) and computed tomography. Metabolic syndrome was defined by modified National Cholesterol Education Program criteria. Metabolic abnormalities were present in 313 patients (30%), including 140 with diabetes (with or without metabolic syndrome) and 173 who had metabolic syndrome without diabetes.


RESULTS
Although CAC scores <100 identified a low likelihood ( approximately 2%) of ischemia, the presence (versus absence) of metabolic abnormalities (metabolic syndrome or diabetes) was a predictor of more frequent ischemia among patients with CAC scores of 100-399 (13.0 vs. 3.6%, P < 0.02) and CAC scores >/=400 (23.4 vs. 13.6%, P = 0.03). Similar trends were observed when patients with metabolic syndrome and diabetes were considered separately. Multiple logistic regression revealed the odds of MPS ischemia to be 4.3-fold greater per SD of log CAC (P < 0.001) and 2.0-fold greater in the presence of metabolic abnormalities (P < 0.01).


CONCLUSIONS
Among patients with CAC scores >/=100, metabolic abnormalities, and even metabolic syndrome in the absence of diabetes predicted a higher likelihood of inducible ischemia. These findings suggest the need for assessment of metabolic status when interpreting the results of CAC imaging among patients undergoing such testing because of suspected CAD.
Wong
Nathan D
ND
Director of Cardiac Imaging, Cedars-Sinai Medical Center, 8700 Beverly Bldg., Room 1258, Los Angeles, CA 90048, USA.
Rozanski
Alan
A
Gransar
Heidi
H
Miranda-Peats
Romalisa
R
Kang
Xingping
X
Hayes
Sean
S
Shaw
Leslee
L
Friedman
John
J
Polk
Donna
D
Berman
Daniel S
DS
D000704:Analysis of Variance; D001161:Arteriosclerosis / Q000453:epidemiology*; D002118:Calcium / Q000032:analysis; D048909:Diabetes Complications / Q000453:epidemiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications*; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000453:epidemiology*; D011336:Probability; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D014481:United States / Q000453:epidemiology
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D002118:Calcium