title: High-sensitivity troponin T as a biomarker for the development of atrial fibrillation after cardiac surgery.
abstract: OBJECTIVE
  Atrial fibrillation (AF) occurs in ∼ 30% of patients undergoing coronary artery bypass grafting (CABG) and in 40% of patients after valve surgery. High-sensitivity cardiac troponin T (hsTnT) is a specific and high-sensitivity marker of myocardial injury, while N-terminal proB-type natriuretic peptide (NT-proBNP) is an established biomarker for wall remodelling. We investigated whether hsTnT and NT-proBNP levels could be used as valuable biomarkers for AF occurrence after cardiac surgery.
  
  
  METHODS
  We included consecutive haemodynamically stable patients undergoing programmed cardiac surgery with cardiopulmonary bypass pump. We determined hsTnT and NT-proBNP levels before and after cardiac surgery and recorded AF development by prolonged electrocardiogram monitoring.
  
  
  RESULTS
  We included 100 patients with predominantly aortic valve (n = 42) or ischaemic heart (n = 58) diseases. Twenty-nine patients (29%) developed post-surgical AF. Patients developing AF had a longer hospital stay (P = 0.005). hsTnT levels increased after surgery [P < 0.001], indicating perioperative myocardial injury, with higher presurgery levels in patients who developed AF [P = 0.015]. Body mass index and EuroSCORE risk scale were independently associated with higher hsTnT levels presurgery. On univariate analysis, age (P = 0.048), male sex (P = 0.031), indexed left atrial volume (P = 0.042), β-blockers treatment (P = 0.024), type of surgery (valve surgery vs CABG; P = 0.034), EuroSCORE risk scale (P = 0.025) and higher preoperative hsTnT levels (P = 0.009) were predictors of AF development, but NT-proBNP did not reach statistical significance (P = 0.060). hsTnT levels in blood samples obtained the day after surgery were not associated with post-surgical AF development (P = 0.165). In a multivariate model, only higher hsTnT levels before cardiac surgery (>11.87 ng/l) [Odds Ratio, OR; (95% Confidence interval, CI) 4.27 (1.43-12.77), P = 0.009] and male sex [OR 5.10 (1.72-15.13), P = 0.003)] were independently associated with the occurrence of post-surgical AF.
  
  
  CONCLUSIONS
  High presurgical hsTnT levels were independently predictive of patients developing AF after cardiac surgery. hsTnT levels determined post-surgery suggest that cardiac perioperative myocardial injury is not associated with postoperative AF development. NT-proBNP did not reach statistical significance as a biomarker for AF prediction.
authors.affiliation: Hospital Universitario Virgen de la Arrixaca, Universidad de Murcia, Murcia, Spain.
authors.forename: Diana
authors.initials: D
authors.lastname: Hernández-Romero
authors.forename: Juan Antonio
authors.initials: JA
authors.lastname: Vílchez
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Lahoz
authors.forename: Ana I
authors.initials: AI
authors.lastname: Romero-Aniorte
authors.forename: Esteban
authors.initials: E
authors.lastname: Orenes-Piñero
authors.forename: Luis
authors.initials: L
authors.lastname: Caballero
authors.forename: Rubén
authors.initials: R
authors.lastname: Jara-Rubio
authors.forename: José María
authors.initials: JM
authors.lastname: Arribas
authors.forename: Arcadio
authors.initials: A
authors.lastname: García-Alberola
authors.forename: Mariano
authors.initials: M
authors.lastname: Valdés
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
authors.forename: Francisco
authors.initials: F
authors.lastname: Marín
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood* / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood / Q000209:etiology; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors; D020107:Troponin T / Q000097:blood*
chemical_list: D015415:Biomarkers; D020107:Troponin T
keywords: Atrial fibrillation; Atrial remodelling; Cardiac surgery; hsTnT