State of the coronary arteries and assessment of the role of hormone replacement therapy in patients with coronary heart disease against the background of primary manifest hypothyroidism

Aim To study features of coronary damage and incidence of different types of acute coronary syndrome (ACS) in history associated with primary symptomatic hypothyroidism in patients with ischemic heart disease (IHD) and possible associations of replacement hormonal therapy with lipidogram indexes.Material and methods This retrospective study included 344 patients with IHD and functional class I-III stable angina (ССS, 1976). Of them 100 patients had primary symptomatic hypothyroidism and 244 had no hypothyroidism. Coronary angiography was performed for all patients included into this study. Routine laboratory, instrumental and clinical indexes were analyzed. Hypothyroidism was confirmed by levels of thyrotropic hormone, free triiodothyronine, and thyroxine. Comparative analysis was performed for the incidence of ACS types in history, types of coronary injury, and laboratory, instrumental and clinical indexes with assessment of potential interrelations. Statistically significant results were reported. Type of data distribution was evaluated with the Kolmogorov-Smirnov test. Quantitative data with normal (Gaussian) distribution were presented as mean (M) and standard deviation (SD). Data with attributes of non-normal distribution were presented as median (Me) with maximum and minimum values (min; max). Statistical significance of differences between means was assessed with the Mann-Whitney test. Logistic regression analysis was used in parallel for evaluating dependence of a quantitative variable on values of two or more quantitative or qualitative variables (factors). Significance level for testing of statistical hypotheses was р<0.05.Results Incidence of ST segment elevation ACS (STEACS) was significantly higher in IHD patients with hypothyroidism than in the group without hypothyroidism (61.6 and 35.6 %, р=0.03) and also with three-vessel coronary artery disease (60.6 and 30.6 %, р=0.001). In the IHD group with hypothyroidism, levels of total cholesterol, triglycerides, and low- and very low-density lipoproteins were significantly increased compared to the respective values in patients without hypothyroidism (р<0.0001). An inverse correlation was found between lipidogram indexes and L-thyroxine (р<0.0001).Conclusion The incidence of STEACS associated with primary symptomatic hypothyroidism in history was significantly higher in the patient group with IHD on the background of primary symptomatic hypothyroidism compared to the comparison group. Also, the incidence of three-vessel coronary disease was significantly greater than in the IHD patient group without hypothyroidism. A significant association was found between the replacement hormonal therapy and the best lipidogram indexes. The authors suggested that the key factor for prevention of adverse cardiovascular events in IHD with hypothyroidism is achieving control of clinical manifestations of hypothyroidism with replacement hormonal therapy.