Lower FT3 levels are associated with a poor prognosis in patients with acute type A aortic dissection: a...

Thyroid hormones are closely associated with cardiovascular disease and the use of thyroid hormones as prognostic indicators in cardiovascular disease patients has recently renewed interest. The purpose of this study was to investigate the prognostic value of free triiodothyronine (FT3) levels in patients with acute type A aortic dissection (AAAD).

A retrospective cohort study was conducted on patients who underwent AAAD surgery in Fujian Medical University Union Hospital between January 2020 and June 2024. The patients were divided into three groups (Tertile 1, Tertile 2, and Tertile 3) based on the tertiles of preoperative FT3 levels. The primary outcomes were in-hospital mortality and prolonged mechanical ventilation (PMV). Logistic regression model was used to explore the effect of FT3 concentration on in-hospital mortality and PMV. Further subgroup analyses were conducted to evaluate the consistency of risk associations across different patient subgroups.

This study included a total of 511 patients, categorized into three FT3 tertiles. Compared to Tertile 3, patients in Tertile 1 and Tertile 2 were older, had a higher incidence of hypertension, elevated troponin levels, body mass index (BMI), a higher proportion of smokers, and lower levels of albumin, platelets, and hemoglobin (all P < 0.05). Compared to non-death and non-PMV patients, death and PMV patients had significantly lower FT3 levels. After multivariable adjustment, FT3 remained an independent predictor of both in-hospital mortality and PMV. For every 1 pmol/L increase in FT3, the in-hospital mortality rate decreased by 33.0% (OR = 0.670, P = 0.039), and the risk of PMV decreased by 33.3% (OR = 0.667, P = 0.008). Compared to Tertile 1, the adjusted OR for in-hospital mortality were 0.652 for Tertile 2 (P = 0.220) and 0.413 for Tertile 3 (P = 0.030). For PMV, the adjusted OR were 0.563 for Tertile 2 (P = 0.024) and 0.4502 for Tertile 3 (P = 0.011). Stratified analysis demonstrated that lower FT3 levels were consistently associated with higher in-hospital mortality across all subgroups.

Lower FT3 levels are independently associated with in-hospital mortality and PMV in AAAD patients. These findings suggest that FT3 may serve as a valuable prognostic biomarker in AAAD patients, warranting further prospective validation studies.