Troponin-T as predictor of mortality in patients attending the emergency department with atrial fibrillation.

Background: High-sensitive Troponin-T (hsTnT) is often increased in acute illness and may be of prognostic importance in patients with atrial fibrillation (AF). The aim of this study was to analyse the characteristics and data of patients attending the emergency department (ED) with AF to determine whether age-adjusted hsTnT levels can predict mortality.

Methods: This retrospective, single centre, register-based cohort study included all patients ≥ 18 years attending the emergency department during 2018 and 2020 with a primary diagnosis at the ED of AF and sampled for hsTnT. Symptoms, comorbidities, lab results, and characteristics were registered. Patients were divided into groups based on hsTnT level (< 15, 15-50, and > 50 ng/L).

Primary outcomes: 30-day and 1-year mortality.

Results: A total of 625 patients were included (median age 72, and 45% female). All-cause mortality was 2% at 30 days and 8% at 1-year. The hazard ratio (HR) for 30-day mortality was 4.17 (95% confidence interval (CI) 0.49-35.79, p = 0.192) for hsTnT 15-50 ng/L and 9.64 (95% CI 0.98-95.30, p = 0.053) for hsTnT > 50 ng/L compared to hsTnT < 15 ng/L when adjusted for age. The HR for 1-year mortality was 4.82 (95% CI 1.81-12.82, p = 0.002) for hsTnT 15-50 ng/L and 9.70 (95% CI 3.27-28.74, p < 0.001) for hsTnT > 50 ng/L compared to hsTnT < 15 ng/L when adjusted for age.

Conclusions: Elevated hsTnT levels increase the risk for 30-day and 1-year mortality independently of age. Both mild and major elevation of hsTnT levels is associated with increased risk for 1-year mortality regardless of age.