title: High-degree atrioventricular block, asystole, and electro-mechanical dissociation complicating non-ST-segment elevation myocardial infarction.
abstract: Non-ST-segment myocardial infarction (NSTEMI) can be complicated by high-degree atrioventricular (AV) block, asystole, or electromechanical dissociation (EMD), but these events are not well characterized in the contemporary era. This analysis assesses the incidence of and factors associated with these dysrhythmias in acute NSTEMIs.
  
  
  METHODS
  Patients with NSTEMI in the EARLY ACS, PLATO, and TRACER trials were included in the pooled cohort (N = 29,677). Logistic regression was used to identify factors associated with in-hospital high-degree AV block and asystole or EMD, and Kaplan-Meier methods were used to assess mortality.
  
  
  RESULTS
  High-degree AV block occurred in 112 (0.4%) patients, asystole in 157 (0.5%), and EMD in 38 (0.1%). Pacemakers were inserted in 241 patients (0.8%) during the index hospitalization: 30 (12%) for AV block. Among patients with high-degree AV block, we observed more frequent right coronary artery lesions (47% vs 29%). Age, diabetes, lower heart rate, and lower blood pressure were associated with high-degree AV block. Higher Killip class, ST-segment depression, prior myocardial infarction, and peripheral vascular disease were most strongly associated with asystole or EMD. Ten-day unadjusted survival was 90% for patients with high-degree AV block and 43% for those with asystole or EMD.
  
  
  CONCLUSIONS
  Although high-degree AV block, asystole, and EMD were infrequent complications of NSTEMI, they were associated with substantial short-term mortality. Only 1 in 8 pacemakers placed in NSTEMI patients during the acute hospitalization was for high-degree AV block.
authors.affiliation: Duke University Medical Center, Durham, NC; Duke Clinical Research Institute, Durham, NC. Electronic address: sean.pokorney@duke.edu.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Pokorney
authors.affiliation: Duke Clinical Research Institute, Durham, NC.
authors.forename: Christina
authors.initials: C
authors.lastname: Radder
authors.affiliation: Duke Clinical Research Institute, Durham, NC.
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Schulte
authors.affiliation: Duke University Medical Center, Durham, NC; Duke Clinical Research Institute, Durham, NC.
authors.forename: Sana M
authors.initials: SM
authors.lastname: Al-Khatib
authors.affiliation: Duke University Medical Center, Durham, NC; Duke Clinical Research Institute, Durham, NC.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Tricocci
authors.affiliation: Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Frans
authors.initials: F
authors.lastname: Van de Werf
authors.affiliation: Uppsala Clinical Research Institute, Uppsala, Sweden.
authors.forename: Stefan K
authors.initials: SK
authors.lastname: James
authors.affiliation: Brigham and Women's Hospital, Boston, MA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Cannon
authors.affiliation: University of AB, Edmonton, Canada.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Armstrong
authors.affiliation: Auckland City Hospital, Auckland, New Zealand.
authors.forename: Harvey D
authors.initials: HD
authors.lastname: White
authors.affiliation: Duke University Medical Center, Durham, NC; Duke Clinical Research Institute, Durham, NC.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Califf
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA.
authors.forename: C Michael
authors.initials: CM
authors.lastname: Gibson
authors.affiliation: Brigham and Women's Hospital, Boston, MA.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Giugliano
authors.affiliation: Uppsala Clinical Research Institute, Uppsala, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Wallentin
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Kenneth W
authors.initials: KW
authors.lastname: Mahaffey
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Palo Alto, CA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Harrington
authors.affiliation: Duke University Medical Center, Durham, NC; Duke Clinical Research Institute, Durham, NC.
authors.forename: L Kristin
authors.initials: LK
authors.lastname: Newby
authors.affiliation: Duke University Medical Center, Durham, NC; Duke Clinical Research Institute, Durham, NC.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Piccini
mesh_terms: D000368:Aged; D054537:Atrioventricular Block / Q000453:epidemiology / Q000209:etiology*; D004562:Electrocardiography; D005260:Female; D006323:Heart Arrest / Q000453:epidemiology / Q000209:etiology*; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000401:mortality; D012307:Risk Factors; D014481:United States / Q000453:epidemiology