Thyroid dysfunction and ischemic heart disease--clinical correlations, progressive implications and impact on the...

Thyroid dysfunctions are associated with systolic and diastolic heart dysfunction, hypertension, rhythm disorders, etc. Clinically significant hyperthyroidism and hypothyroidism may have an impact on the patients with ischemic heart disease.

Investigation of the risk of developing ischemic heart disease, of the evolution and prognosis in relation to the entire spectrum of thyroid dysfunctions.

All participants included in the study were selected from among subjects with heart disorders who were controlled with concern to the thyroid hormonal condition and who hadn't been treated previously for thyroid functional disorders. Based on these criteria we defined a study group made out of 791 subjects, divided into five lots based on the level of thyroid hormones. Once the group was formed, we conducted evaluations of the cardiovascular and thyroid status at 6 and 12 months, respectively.

In the witness lot, during monitoring 49% of the patients showed an ischemic heart disease. The main risk factors were: heart frequency of over 80 beats/min (RR = 1.83), age over 60 (RR = 1.47), female sex (RR = 1.21) and values of triglycerides over 160 mg/dl (RR = 1.23). In the group of patients with overt clinic hyperthyroidism, during monitoring 46.1% showed ischemic heart disease. The main risk factors were: heart frequency over 80 beats/min (RR = 2.41), age over 60 (RR = 1.67), high level of LDL-cholesterol (RR = 1.53) and female sex (RR = 1.31). Among the patients with overt clinical hyperthyroidism, during monitoring 53.3% showed ischemic heart disease. The main risk factors identified were: heart frequency over 80 beats/min (RR = 2.01), age over 60 (RR = 1.42), high levels of triglycerides (RR = 1.42) and LDL-cholesterol (RR = 1.32), as well as the presence of hypertension in the health records (RR = 1.31).

Thyroid dysfunction is a common clinical condition with a key role in the regulation of the cardiovascular system and may contribute to the evolution of the ischemic heart disease and which should be taken into consideration when patients with heart disease are treated. In this light, thyroid function needs to be evaluated for all patients with a risk for ischemic heart disease.