P6155Significance of non-thyroidal illness syndrome in patients with dilated cardiomyopathy

Abstract

Introduction: Non-thyroidal illness syndrome (NTIS), represented by decreased concentration of plasma triiodothyronine (T3) levels and normal range of thyroidstimulating hormone (TSH), is commonly seen in patients with severe systemic disease. Systemic inflammation and nutritional disorder are considered as main components associated with the development of NTIS. Several recent reports are keenly interested in inflammation and malnutrition in heart failure pathophysiology; however, little is known about the significance of NTIS in cardiomyopathy. Purpose: The aim of this study was to clarify the clinical impact of NTIS in patients with dilated cardiomyopathy (DCM). Methods: A total of 482 patients who were diagnosed as DCM were reviewed. We excluded patients from this study for at least one of the following reasons: abnormal TSH value, past history of thyroid disease, no obtainable thyroid function tests, under antithyroid or thyroid hormone medication, or amiodarone therapy. Finally, 251 patients were included in this study. Baseline demographic data, laboratory data including thyroid function, physiological data including cardiopulmonary exercise test, and hemodynamic data were obtained. Controlling Nutritional Status (CONUT) score (range 0-12, higher=worse, consisting of serum albumin, cholesterol and lymphocytes) was calculated for the assessment of nutritional status. In addition, survival analysis was performed. Results: Forty-two patients (17%) were diagnosed as NTIS, having free T3 levels less than normal limit. Patients with NTIS showed significantly lower BMI levels (21.3±4.1 vs. 24.3±4.8 kg/m2, p=0.002), higher CRP levels (0.32±0.37 vs. 0.17±0.20 mg/dl, p=0.02), higher CONUT scores (2.3±2.0 vs. 1.2±1.2, P=0.001), higher prevalence of NYHA class >III (50 vs. 13%, p<0.001) and lower peak VO2 levels measured by cardiopulmonary exercise test (17.2±3.7 vs. 22.2±4.9 ml/min/kg, p=0.002) compared to those without NTIS. Hemodynamically, NTIS was associated with higher LVEDP (16±8 vs. 12±8 mmHg, p=0.009), higher mean PA pressure (22±10 vs. 17±8 mmHg, p=0.002). Survival analysis revealed that transplantation-free survival was significantly lower in NTIS (median follow-up period of 3.3 years, p=0.03). Conclusions: NTIS was associated with malnutrition, increased systemic inflammation, hemodynamic compromise, and poor outcome in DCM patients, indicating possible pathophysiological impact in the development and worsening of heart failure.