Likelihood of obstructive coronary disease in metabolic syndrome patients with abnormal stress echocardiography.

Background: Metabolic syndrome (MetSx) encompasses several risk factors for macrovascular coronary artery disease. An association between MetSx and coronary syndrome X has also been reported, suggesting that patients with MetSx are more likely to have endothelial dysfunction in the setting of angiographically normal coronary arteries. It remains unknown whether MetSx patients with abnormal stress echocardiography (SE) are more likely to have obstructive coronary disease (CAD) compared to patients without MetSx.

Methods: We identified symptomatic patients without known CAD and abnormal SE who underwent coronary angiography within 4 weeks after the SE. Patients were grouped according to their MetSx and impaired fasting glucose (IFG) status. We compared the proportion of patients with obstructive CAD in each subgroup using the x(2) test. Multivariate regression analysis was used to adjust for the pre-test probability of underlying coronary artery disease.

Results: Among 583 consecutive symptomatic patients who had an abnormal SE and were referred for angiography, 158 (36%) met the NCEP definition of MetSx. MetSx patients had a trend towards having more obstructive CAD than those without MetSx (OR 1.44, p = 0.07). After adjusting for pre-test probability of coronary disease, smoking and LDL-C, MetSx/IFG combination was an independent predictor of obstructive CAD (OR 2.06 [1.24-3.44], p < 0.001) but MetSx with normal fasting blood glucose was not (OR 0.91 [0.47-1.70], p 0.09).

Conclusion: Symptomatic patients with MetSx and IFG are more likely to have angiographically significant CAD after abnormal SE than patients without MetSx or those with normal fasting blood glucose.