A Demographic Profile of ACS Associated with Thyroid Dysfunction in North Indian Population

Abstract

Background: Thyroid disorders have an important bearing on the cardiovascular (CV) system leading to hypertension, dyslipidemia, heart rhythm disorders, obesity etc. Data regarding the influence of subclinical hypothyroidism and CV disease and outcomes have been conflicting. Since subclinical hypothyroidism is seen often in clinical syndromes of coronary artery disease, we undertook this study to evaluate the overall prevalence and demography of patients admitted with the diagnosis of ACS in a North Indian population. Methods: We studied consecutive 171 hospitalized patients between March 2018 to February 2020 with a diagnosis of acute coronary syndrome (ACS) to determine the features of thyroid dysfunction both clinical and sub-clinical and the associated biochemical parameters. All patients underwent complete medical history of cardiac risk factors for developing CAD. Thyroid function Tests - free T3, free T4 and TSH were collected from all the patients within 24 hours of admission to CCU. Results: Forty (23%) of these patients had thyroid dysfunction. Subclinical hypothyroidism was the commonest abnormality seen in 26 (23%), followed by overt hypothyroidism 12 (9%). Hyperthyroidism was uncommon (1.5%). Euthyroid sick syndrome was seen in 4% and these patients were excluded.  There was a predilection for the elderly population (females 52%).  STEMI (52%) followed by NSTEMI (25%) was the commonest diagnosis at presentation. A significant correlation was seen with serum lipid levels (decreased HDL C, Increased total cholesterol, triglycerides and VLDL C) and hypothyroidism. However, there was no correlation ship with LDL C. Reduced e glomerular filtration rate (e GFR) which was seen in 50% of patients had a linear relationship with hypothyroidism. Patients with hypothyroidism had no differences in the prevalence of concomitant diabetes and hypertension. The left ventricular ejection fraction (LVEF) in the group of patients had a trend to be lower. Conclusions: Hypothyroidism seems to be an important risk factor in patients with ACS, especially STEMI.  The impairment of renal function was also prominent in these patients. These patients also suffered from impaired renal function.