title: Predictors of cardiac events in high-risk patients undergoing emergency surgery.
abstract: BACKGROUND
  The aim of this study was to determine the incidence of myocardial damage and left ventricular myocardial dysfunction and their influence on outcome in high-risk patients undergoing non-elective surgery.
  
  
  METHODS
  In this prospective observational study, 211 patients with American Society of Anesthesiologists classification III or IV undergoing emergent or urgent surgery were included. Troponin I (TnI) was measured pre-operatively, 12 and 48 h post-operatively. Pre-operative N-terminal fragment of B-type natriuretic peptide (NT-proBNP), as a marker for left ventricular systolic dysfunction, was analyzed. The diagnostic thresholds were set to TnI >0.06 microg/l and NT-proBNP >1800 pg/ml, respectively. Post-operative major adverse cardiac events (MACE), 30-day and 3-months mortality were recorded.
  
  
  RESULTS
  Elevated TnI levels were detected in 33% of the patients post-operatively. A TnI elevation increased the risk of MACE (35% vs. 3% in patients with normal TnI levels, P<0.001) and 30-day mortality (23% vs. 7%, P=0.003). Increased concentrations of NT-proBNP were seen in 59% of the patients. Elevated NT-proBNP was an independent predictor of myocardial damage post-operatively, odds ratio, 6.2 [95% confidence interval (CI) 2.1-18.0] and resulted in an increased risk of MACE (21% vs. 2.5% in patients with NT-proBNP < or = 1800 pg/ml, P<0.001).
  
  
  CONCLUSIONS
  Myocardial damage is common in a high-risk population undergoing unscheduled surgery. These results suggest a close correlation between myocardial damage in the post-operative period and increased concentration of NT-proBNP before surgery. The combinations of TnI and NT-proBNP are reliable markers for monitoring patients at risk in the peri-operative period as well as useful tools in our risk assessment pre-operatively in emergency surgery.
authors.affiliation: Department of Medical & Health Sciences, Division of Anaesthesia, Linkoping University, Linkoping, Sweden. anna.oscarsson.tibblin@lio.se
authors.forename: A
authors.initials: A
authors.lastname: Oscarsson
authors.forename: M
authors.initials: M
authors.lastname: Fredrikson
authors.forename: M
authors.initials: M
authors.lastname: Sörliden
authors.forename: S
authors.initials: S
authors.lastname: Anskär
authors.forename: A
authors.initials: A
authors.lastname: Gupta
authors.forename: E
authors.initials: E
authors.lastname: Swahn
authors.forename: C
authors.initials: C
authors.lastname: Eintrei
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D004632:Emergency Medical Services; D023381:Endpoint Determination; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology; D006334:Heart Function Tests; D006801:Humans; D008297:Male; D009206:Myocardium / Q000473:pathology; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D011237:Predictive Value of Tests; D012372:ROC Curve; D012306:Risk; D013514:Surgical Procedures, Operative / Q000401:mortality; D016019:Survival Analysis; D019210:Troponin I / Q000097:blood
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D019210:Troponin I; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain