Prognostic Value of Troponin in Patients with Atrial Fibrillation Admitted to an Emergency Department: Review and Meta-Analysis.

Introduction: Elevated levels of cardiac troponin (cTn) indicate underlying heart disease and is known to predict adverse events in multiple conditions. Its role in atrial fibrillation (AF) in the acute setting is still not conclusive. We aimed to assess the prognostic value of c-Tn in patients with AF admitted to an emergency department (ED).

Methods: Systematic searches were conducted using PubMed and the Cochrane Library and the International Clinical Trials Registry Platform to identify studies from year 2009 to October 2019 reporting on the prognostic value of cTn on all-cause mortality or major adverse cardiac events (MACE) in adult patients with AF in the ED. We pooled hazard ratio (HR) and 95% confidence interval (CI) using fixed and random effects models according the heterogeneity. We planned to conduct a sensitivity and subgroup analyses.

Results: Five studies involving 5750 patients were identified. The mean follow-up ranged from 12 to 35 months. An increase in mortality was observed in the elevated cTn group compared to the controls, HR=2.7 (95% CI 1.55-4.72), P for effect<0.001, I2=80%). For MACE, the pooled HR was 2.17 (95%CI 1.60-2.94), P for effect<0.001, I2=0%). In the subgroup analysis we found no significant difference in type of troponin used and study design.

Conclusions: The elevation of cardiac troponin was significantly associated with higher mortality and major adverse cardiac events in patients with AF admitted to an ED. In this setting the use of c-Tn could provide prognostic information.