Aspects of the development of hypothyroid cardiomyopathy associated with chronic systemic inflammation

Abstract

Background. Cardiovascular manifestations are rated first among the symptoms of hypothyroidism. Since the highest prevalence of both coronary heart disease (CHD) and hypothyroidism is observed in the age group over 50 years old, the problem of combination of these nosologies in older people is increasing. Aim of the study is to investigate the structural and functional state of the left ventricular myocardium in hypothyroidism and CHD associated with chronic systemic inflammation. Materials and methods. To reach the objectives of the study, a randomized controlled clinical trial has been conducted in parallel groups of patients with hypothyroidism, CHD and combination of both. To form the main group, a screening analysis of 556 medical histories of patients with hypothyroidism and CHD during the period of 2006–2015 has been made, which were selected for further study. Results. It has been found that myocardial hypertrophy develops in all groups of patients, a decrease in thyroid function leads to remodeling of the left ventricular myocardium with the development of eccentric hypertrophy and the progression of systolic heart failure in comorbidity. A direct correlation between reduced ejection fraction and elevated interleukin-8 level has been detected. Evaluation of the state of chronic systemic inflammation revealed a significant increase in the level of interleukin-8 in patients with coronary heart disease associated with hypothyroidism (7.66 ± 2.18 pg/ml; p < 0.05). This indicate that the persistence of pro-inflammatory state in patients with combined pathology is a negative prognostic factor for the development of cardiovascular complications. Conclusion. During echocardioscopy of patients with hypothyroidism, the impaired central hemodynamics can be determined by the indicators of the diastolic and systolic heart function. In patients with isolated hypothyroidism and in combination with coronary heart disease, thickening of the left ventricular myocardial walls is noted, which proves the specificity of changes in the heart geometry that leads to the development of eccentric hypertrophy. This can be considered as the marker of a “hypothyroid” heart whose severity can determine the severity of hypothyroidism. Activation of chronic systemic inflammation is more pronounced in conditions of comorbidity, with a negative prognostic effect on the state of the cardiovascular system.