P5513Relation of thyroid hormones level to the extent of myocardial injury in patients with acute coronary syndrome

Abstract

Abstract Objective Previous studies have identified that abnormal thyroid hormonal status is associated with worse prognosis especially in coronary artery disease (CAD). The present study further explores whether thyroid hormones associated with size of myocardial injury and extent of CAD in patients with acute coronary syndrome (ACS). Methods In this study, we enrolled 120 consecutive patients (52% male, mean age 54.2±6.4 years) who were admitted to ICU with ACS and having coronary angiography. All patients underwent testing for thyroid function status [thyroid stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4)], cardiac troponin I (cTnI), cardiac enzymes, C-reactive protein (CRP). Risk profile, clinical characteristics and angiographic results (Gensini score) were also analyzed. Results 43.3% of patients presented with STEMI, 33.3% with NSTEMI and 23.3% unstable angina. CK-MB, troponin and CRP were significantly higher in STEMI compared with NSTEMI group (P<0.0001). Abnormal thyroid status was prevalent in 13.4% of total population; Low FT3 syndrome in 6.7%, subclinical hypothyroidism in 5% and clinical hypothyroidism in 1.7%. Lower thyroid hormone levels showed significantly lower HDL (P<0.02), higher triglyceride level& CRP and cTnI (P<0.007), higher rate of in hospital complications including recurrent angina, CHF and cardiogenic shock (P<0.001) and more severe CAD using Gensini score (P<0.0001). However, there was no significant difference in abnormal thyroid status between STEMI and NSTEMI. After adjusting for conventional risk factors, FT3 showed direct correlation to LV EF% (r=0.62, P<0.000) and inverse correlation to LV internal dimension (r=−0.57, P<0.0001), troponin (r=−0.27, P<0.03), CRP (r=−0.39, P<0.003), Gensini score (r=−0.48, P<0.0001) and number of in hospital complications (r=−0.62, P<0.0001). From a linear stepwise regression analysis low EF% (β: 0.032, 95% CI: 0.009–0.055, P<0.007) and presence of complications (β: 0.625, 95% CI: 1.194–0.056, P<0.03) are independent predictors of low FT3. Conclusions In ACS, the lower thyroid hormones levels are associated with larger myocardial injury, more severe CAD and higher rate of complications especially during their hospital course.