# Free Triiodothyronine Serves as a Potential Predictor of Long-Term Heart Failure Following Acute Myocardial Infarction: A Single-Center Follow-Up Study in China

## TL;DR

This study finds that lower free triiodothyronine (FT3) levels predict long-term heart failure after heart attacks in a Chinese population.

## Contribution

The study identifies FT3 as a novel predictor of heart failure in acute myocardial infarction patients in China.

## Key findings

- Lower FT3 levels are independently associated with long-term heart failure after AMI.
- Kaplan-Meier analysis shows reduced HF-free survival with lower FT3 levels.
- FT3 has good predictive performance with an AUC of 0.736 for long-term HF.

## Abstract

This study explored the potential role of FT3 in predicting long-term heart failure (HF) in patients with acute myocardial infarction (AMI), so as to provide relevant information about the Chinese population.

This was an observational, retrospective, single-center study of consecutive patients with AMI enrolled at the Affiliated Hospital of Yangzhou University. The patients were divided into the HF group or the non-HF group according to the occurrence of HF after AMI. Cox proportional hazards regression models identified factors independently associated with long-term HF. The patients were segregated into two groups by the median level of FT3 (4.63 pmol/L): the Group 1 (< 4.63 pmol/L) and the Group 2 (> 4.63 pmol/L), and the Kaplan–Meier survival analysis was used to estimate the HF-free survival between the two groups. The receiver operating characteristic (ROC) curves were used to evaluate the predictive performance of FT3 on long-term HF among patients with AMI.

A total of 269 AMI patients were included. Multivariable Cox regression analysis indicated that age (p < 0.001), FT3 (p=0.030), and LVEF (p < 0.001) were independent prognostic factors for long-term HF after AMI. The Kaplan–Meier survival analysis revealed a significantly lower HF-free survival rate in patients with lower FT3 levels (p < 0.01). The ROC analysis revealed that FT3 exhibited good predictive performance for long-term HF after AMI, with an AUC of 0.736 (p < 0.01).

Lower levels of FT3, even within the normal range, not only serve as independent risk factors for long-term HF after AMI but also predict a higher incidence of it.