Metabolic Syndrome is the Main Predictor of Myocardial Ischemia in SPECT

Background: Data show that metabolic syndrome (MS) increases the risk of cardiovascular disease. Objectives: To describe and compare the scintigraphic abnormalities and the predictive value of myocardial ischemia in individuals with and without MS referred for single photon emission computed tomography (SPECT) in a University Hospital using three diagnostic criteria. Methods: Prospective observational study of patients referred for SPECT from June to December 2010. Height, weight and waist circumference were measured. Risk factors were assessed and medical records were reviewed to look for parameters for laboratory diagnosis of MS and complete SPECT reports. Results: The study included 203 patients; 138 women (68.0%); mean age 63.6±11.5 years. Metabolic syndrome was found in 135 patients (66.5%). Of the 99 abnormal tests, 91.9% (n=91) occurred in patients with MS and 8.1% (n=8) in patients without MS. There was a significant association between MS and abnormal scintigraphy (67.0% vs. 11.8%; p<0.001) and patients with MS had abnormalities of greater extent and severity (summed stress score (SSS)=7.3±6.5 vs. 3.0±0.9; p<0.001 and summed difference score (SDS)=3.4±4.3 vs. 0.9±2.5; p<0.001). MS was an independent predictor of myocardial ischemia in the three definitions studied (OR=10.07, 6.25 and 4.26 for modified NCEP-ATP III, NCEP-ATP III and IDF, respectively). Conclusions: Patients with MS had more perfusion defects on SPECT (both fixed and reversible); and MS defined by the modified NCEP-ATP III was the best independent predictor of myocardial ischemia on scintigraphy.