title: High-grade atrioventricular block in acute coronary syndromes: insights from the Global Registry of Acute Coronary Events.
abstract: BACKGROUND
  While prior work has suggested that a high-grade atrioventricular block (HAVB) in the setting of an acute coronary syndrome (ACS) is associated with in-hospital death, limited information is available on the incidence of, and death associated with, HAVB in ACS patients receiving contemporary management.
  
  
  RESULTS
  The incidence of HAVB was determined within The Global Registry of Acute Coronary Events (GRACE). The clinical characteristics, in-hospital therapies, and outcomes were compared between patients with and without HAVB. Factors associated with death in patients with HAVB were determined. A total of 59 229 patients with ACS between 1999 and 2007 were identified; 2.9% of patients had HAVB at any point during the index hospitalization; 22.7% of whom died in hospital [adjusted odds ratio (OR) = 4.2, 95% confidence interval (CI), 3.6-4.9, P < 0.001]. The association between HAVB and in-hospital death varied with type of ACS [OR: ST-segment elevation myocardial infarction (STEMI) = 3.0; non-STEMI = 6.4; unstable angina = 8.2, P for interaction < 0.001]. High-grade atrioventricular block present at the time of presentation to hospital (vs. occurring in-hospital) and early (<12 h) percutaneous coronary intervention or fibrinolysis (vs.>12 h or no intervention) were associated with improved in-hospital survival, whereas temporary pacemaker insertion was not. Patients with HAVB surviving to discharge had similar adjusted survival at 6 months compared with those without HAVB. A reduction in the rate of, but not in-hospital mortality associated with, HAVB was noted over the study period.
  
  
  CONCLUSIONS
  Although the incidence of HAVB is low and decreasing, this complication continues to have a high risk of in-hospital death.
authors.affiliation: Division of Cardiology, Department of Medicine, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.
authors.forename: Sheldon M
authors.initials: SM
authors.lastname: Singh
authors.affiliation: Center for Outcomes Research, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Gordon
authors.initials: G
authors.lastname: FitzGerald
authors.affiliation: Terrence Donnelly Heart Centre, St Michael's Hospital, University of Toronto, Toronto, Canada.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Yan
authors.affiliation: Coronary Care Unit, Concord Hospital, Sydney, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Brieger
authors.affiliation: Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK.
authors.forename: Keith A A
authors.initials: KA
authors.lastname: Fox
authors.affiliation: Hospital Universitario La Paz, Madrid, Spain.
authors.forename: Jose
authors.initials: J
authors.lastname: López-Sendón
authors.affiliation: University of Toronto, Toronto, Canada.
authors.forename: Raymond T
authors.initials: RT
authors.lastname: Yan
authors.affiliation: University of Michigan Medical Center, Ann Arbor, MI, USA.
authors.forename: Kim A
authors.initials: KA
authors.lastname: Eagle
authors.affiliation: Hôpital Bichat, Assistance Publique, Hôpitaux de Paris, Paris, France.
authors.forename: Ph Gabriel
authors.initials: PG
authors.lastname: Steg
authors.affiliation: Grochowski Hospital, Warsaw, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Budaj
authors.affiliation: Terrence Donnelly Heart Centre, St Michael's Hospital, University of Toronto, Toronto, Canada Canadian Heart Research Centre, Toronto, Canada Division of Cardiology, St Michael's Hospital, 30 Bond Street, Room 6-034 Queen, Toronto, Ontario, Canada M5B 1W8 goodmans@smh.ca.
authors.forename: Shaun G
authors.initials: SG
authors.lastname: Goodman
mesh_terms: D054058:Acute Coronary Syndrome / Q000150:complications / Q000401:mortality*; D000368:Aged; D054537:Atrioventricular Block / Q000150:complications / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000401:mortality; D010138:Pacemaker, Artificial / Q000706:statistics & numerical data; D062645:Percutaneous Coronary Intervention / Q000401:mortality; D011379:Prognosis; D011446:Prospective Studies; D012042:Registries
keywords: Acute coronary syndromes; Artificial pacemaker; Atrioventricular block; Percutaneous coronary intervention