Association of Serum FT3 with Severity of Heart Failure and it’s Correlation with NT-proBNP

Background: Heart failure is a global health emergency affecting millions of people worldwide and is increasing in prevalence. NT-proBNP is a hormone that is a marker of severity and prognosis of heart failure. Thyroid hormone has an important regulatory impact on the heart. Altered thyroid function specially triiodothyronine and increase NT-proBNP are highly prevalent in heart failure patients without apparent thyroid diseases. Objectives: To evaluate the association of serum FT3 with heart failure severity and its correlation with NT-proBNP as a potential marker. Methods: A cross-sectional analytical study was conducted at the Department of Biochemistry, Sir Salimullah Medical College (SSMC), over a 12-month period following ethical approval. A total of 110 clinically diagnosed heart failure subjects were enrolled based on inclusion and exclusion criteria. Written informed consent was obtained from patients and detailed histories, clinical examinations and Serum FT3, serum TSH and serum NT-proBNP were performed. Data was collected using a semi-structured questionnaire and Statistical analysis was done by using SPSS version 22.0. Results: Serum FT3 level was significantly lower among heart failure patients with high NT-proBNP but the mean value of serum TSH was normal. Low FT3 level is associated with more severe heart failure patients having high NT-proBNP levels. Conclusion: Serum FT3 has an inverse relation with NT-proBNP in patients with heart failure. As low FT3 associated with severe heart failure patients with high NT-proBNP, low FT3 could be a potential marker for heart failure severity. Bangladesh Med Res Counc Bull 2024; 50: 104-110