title: Left ventricular ejection fraction and mortality in patients with ST-elevation myocardial infarction and bundle branch block.
abstract: BACKGROUND
  The aim of our study is to assess the effect of bundle branch block (BBB) on mortality and left ventricular ejection fraction (LVEF) in ST-elevation myocardial infarction (STEMI) patients treated in the current era of percutaneous reperfusion therapy.
  
  
  METHODS
  In this retrospective cohort study, a total of 1123 STEMI patients treated in the University Medical Center Groningen from January 2011 until May 2013 were included. The follow-up duration was 2-4 years. Transthoracic echocardiography was performed within 2 weeks after STEMI.
  
  
  RESULTS
  In total, 23 (2.0%) patients presented with left BBB and 49 (4.4%) patients presented with right BBB. Two-year mortality after STEMI was 25.0% (n=18) in patients with BBB and 9.2% (n=97, P<0.001) in patients without BBB. Patients with BBB had more frequently a severely reduced LVEF (<30%) [20.0% (n=6) compared with 4.2% (n=21), P=0.002] and less frequently a normal LVEF [16.7% (n=5) compared with 35.7% (n=179), P=0.046]. After multivariable analysis, BBB did not remain an independent predictor of mortality, but was an independent predictor of reduced LVEF.
  
  
  CONCLUSIONS
  The presence of a BBB was an independent predictor of a reduced LVEF. However, we found no effect of BBB on 2-year mortality in the current era of percutaneous reperfusion therapy.
authors.affiliation: Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
authors.forename: M Yldau
authors.initials: MY
authors.lastname: van der Ende
authors.forename: Minke H T
authors.initials: MH
authors.lastname: Hartman
authors.forename: Tom
authors.initials: T
authors.lastname: Hendriks
authors.forename: Hindrik W
authors.initials: HW
authors.lastname: van der Werf
authors.forename: Erik
authors.initials: E
authors.lastname: Lipsic
authors.forename: Pim
authors.initials: P
authors.lastname: van der Harst
mesh_terms: D000046:Academic Medical Centers; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D062645:Percutaneous Coronary Intervention; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D000072657:ST Elevation Myocardial Infarction / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy; D013318:Stroke Volume; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000401:mortality* / Q000503:physiopathology*; D016277:Ventricular Function, Left