Myocardial perfusion and intima-media thickness in patients with subclinical hypothyroidism

Abstract

The data concerning the relation between subclinical hypothyroidism (SH) and the risk of cardiovascular disease are divergent. We aimed to assess myocardial perfusion in contrast-enhanced echocardiography and intima-media thickness (IMT) in patients with SH. Forty females with SH without symptoms of coronary artery disease and 15 healthy female volunteers were examined. Echocardiographic evaluation of the left ventricle function as well as carotid and femoral IMT complex measurements were performed at baseline. Thereafter, dobutamine stress echocardiography with myocardial perfusion assessment at rest and on the peak of stress test was performed. SonoVue® intravenous bolus as a contrast medium was used. The myocardial perfusion was assessed by quantitative method using Q-LAB Philips software (ROI modality). The perfusion index was calculated (a number of left ventricle segments with improved perfusion/a number of all segments). A mean IMT value in the SH group was significantly higher than in the controls (0.7 mm vs. 0.38 mm, p=0.001). Myocardial perfusion at rest and at the peak of stress test was significantly lower in the SH patients as compared to the controls (at rest 120 Db in SH vs. 181 Db in controls, p=0.039 and at the peak of stress 115 Db and 188 Db, p=0.01, respectively). The perfusion index was not significantly worse in the SH group (p=0.6). IMT values negatively correlated with the myocardial perfusion index at the peak of stress (r=-0.54, p=0.014). In patients with SH contrast-enhanced echocardiographic examination revealed myocardial hypoperfusion and increased IMT. Our results may suggest that the patients with SH are at risk of the development of cardiovascular disease.