Preclinical Alterations in Myocardial Microstructure in People with Metabolic Syndrome

OBJECTIVE: Metabolic syndrome (MetS) can lead to myocardial fibrosis, diastolic dysfunction and eventual heart failure. We evaluated alterations in myocardial microstructure in people with MetS using a novel algorithm to characterize ultrasonic signal intensity variation. METHODS: Among 254 participants without existing cardiovascular disease (mean age 42 ± 11 years, 75% women), there were 162 with MetS, 47 with obesity without MetS, and 45 non-obese controls. Standard echocardiography was performed, and a novel validated computational algorithm was used to investigate myocardial microstructure based on sonographic signal intensity and distribution. We examined the signal intensity coefficient (SIC, left ventricular microstructure). RESULTS: The SIC was significantly higher in people with MetS compared with people with (P<0.001) and without obesity (P=0.04), even after adjustment for age, sex, body mass index, hypertension, diabetes mellitus and triglyceride to HDL cholesterol (TG/HDL) ratio (P<0.05 for all). Clinical correlates of SIC included TG concentrations (r=0.21, P=0.0007) and the TG/HDL ratio (r=0.2, P=0.001). CONCLUSIONS: Our findings suggest that preclinical MetS and dyslipidemia in particular, are associated with altered myocardial signal intensity variation. Future studies are needed to determine whether the SIC may help detect subclinical disease in people with metabolic disease, with the ultimate goal of targeting preventive efforts.