Correlation of hypothyroidism with evidence of coronary artery disease in the myocardial perfusion scan

Abstract

Abstract Purpose Hypothyroidism is one of the most common endocrine diseases. There is evidence that hypothyroidism is related to a higher rate of coronary artery disease (CAD). This study aimed to assess the correlation of hypothyroidism with abnormal perfusion findings in MPI-SPECT images in patients with suspected CAD. Methods In this cross-sectional study, 188 patients with suspected CAD who underwent MPI were included and a thyroid function test (TFT) (TSH, total T4, and total T3) was performed. All patients were categorized in two groups of hypothyroidism and euthyroidism on the basis of the previous history of hypothyroidism and TFT. The frequency and prevalence of abnormal scans in both groups of this study were assessed. The correlation between TFT findings and MPI quantitative and semi-quantitative parameters was also evaluated. Results Of 188 cases, 48 patients (25.5%) were hypothyroid. In the hypothyroid group, on the basis of SSS and TPDs, 20 patients (41.7%) and 22 patients (45.8%) had abnormal perfusion scans, respectively, which was significantly higher than the euthyroid group. There were no significant differences between normal and hypothyroid groups according to frequency of patients’ cardiovascular risk factors, however, there were significant between the two groups with respect to variables of SSS (P < 0.05), SDS (P < 0.05), and TPDr (P < 0.05). Conclusion Hypothyroidism is associated with evidence of CAD in SPECT MPI and should be considered as an independent high-risk factor during interpretation of SPECT MPI.