title: Predictors of significant coronary artery disease in atrial fibrillation: Are cardiac troponins a useful measure.
abstract: BACKGROUND
  Cardiac Troponin I (cTnI) is frequently measured in patients presenting with symptomatic atrial fibrillation (AF). The significance of elevated cTnI levels in this patient cohort is unclear. We investigated the value of cTnI elevation in this setting and whether it is predictive for significant coronary artery disease (sCAD).
  
  
  METHODS
  We conducted a retrospective, single-center, case-control study of 231 patients who presented with symptomatic AF to The Prince Charles Hospital emergency department, Brisbane, Australia between 2006 and 2014. Patients who underwent serial cTnI testing and assessment for CAD were included. Clinical variables that are known to predict CAD and could potentially predict cTnI elevation were collected. Binary logistic regression was performed to identify predictors of sCAD and cTnI elevation.
  
  
  RESULTS
  Cardiac Troponin I elevation above standard cut off was not predictive for sCAD after adjustment for other predictors (OR 1.62, 95% CI 0.79-3.32. p=0.19). However, the highest cTnI concentration value (cTnI peak) was predictive for sCAD (OR 2.02, 95% CI 1.02-3.97, p=0.04). Dyspnea on presentation (OR 4.52, 95% CI 1.87-10.91, p=0.001), known coronary artery disease (OR 3.44, 95% CI 1.42-8.32, p=0.006), and ST depression on the initial electrocardiogram (OR 2.57, 95% CI 1.11-5.97, p=0.028) predicted sCAD in our cohort, while heart rate on initial presentation was inversely correlated with sCAD (OR 0.99, 95% CI 0.971-1.00, p=0.034).
  
  
  CONCLUSIONS
  Troponin elevation is common in patients presenting to hospital with acute symptomatic AF and it is not a reliable indicator for underlying sCAD in this patient cohort. However, cTnI peak was a predictor of significant coronary artery disease.
authors: University of Queensland, Australia; Department of Medicine, Redcliffe Hospital, Redcliffe, Australia. Electronic address: alaa.alghamry@health.qld.gov.au.
authors: Alaa
authors: A
authors: Alghamry
authors: University of Queensland, Australia; Department of Cardiology, The Prince Charles Hospital, Brisbane, Australia.
authors: Joseph
authors: J
authors: Hanna
authors: QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors: Anita
authors: A
authors: Pelecanos
authors: Department of Cardiology, The Prince Charles Hospital, Brisbane, Australia.
authors: Stephen
authors: S
authors: Kyranis
authors: Department of Medicine, Redcliffe Hospital, Redcliffe, Australia.
authors: Vinod
authors: V
authors: Khelgi
authors: QIMR Berghofer Medical Research Institute, Brisbane, Australia.
authors: Peter
authors: P
authors: O'Rourke
authors: Department of Medicine, Redcliffe Hospital, Redcliffe, Australia.
authors: Oran
authors: O
authors: Carroll
authors: Department of Medicine, Redcliffe Hospital, Redcliffe, Australia.
authors: Cassie
authors: C
authors: Oxenford
authors: Department of Medicine, Redcliffe Hospital, Redcliffe, Australia.
authors: Swetha
authors: S
authors: Rangaswamaiah
authors: University of Queensland, Australia; Department of Medicine, Redcliffe Hospital, Redcliffe, Australia.
authors: Christopher
authors: C
authors: Tan
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood / Q000150:complications*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D019210:Troponin I / Q000097:blood*
chemical_list: D015415:Biomarkers; D019210:Troponin I
keywords: Acute coronary syndrome; Atrial fibrillation; Coronary artery disease; Troponin