title: Left bundle branch block with acute thrombotic occlusion is associated with increased myocardial jeopardy score and poor clinical outcomes in primary percutaneous coronary intervention activations.
abstract: OBJECTIVE
  To assess the utility of left bundle branch block (LBBB) as an activation criterion for primary percutaneous coronary intervention (PPCI).
  
  
  METHODS
  Retrospective observational cohort study.
  
  
  METHODS
  Single UK heart attack centre.
  
  
  METHODS
  Consecutive patients referred for PPCI September 2008-December 2011 (n=2192).
  
  
  METHODS
  Demographic and outcome data were obtained by review of case notes, angiograms and interrogation of local/national databases.
  
  
  METHODS
  Angiographic culprit lesion assessment defined appropriate and inappropriate activations. Patients outcomes were assessed by Major adverse cardiac events (MACE), defined as a composite of mortality and unplanned revascularisation at 1-year.
  
  
  RESULTS
  LBBB-activation occurred in 120 patients (5.5%), of whom 21 (17.5%) had acute coronary occlusion angiographically, and were adjudicated appropriately. Compared with appropriate activations for ST segment elevation, appropriate LBBB-activations were older (71.0 ± 9.6 vs 64.2 ± 12.4 years, p=0.01) and more likely to be in cardiogenic shock (19.0% vs 4.3%, p<0.01). Extent of disease quantified by the SYNTAX score did not differ (median 21.5, IQR 11.0-27.0 vs 19, 11.0-25.5, p=0.66), but amount of myocardium at-risk was higher in appropriate LBBB-activations (culprit jeopardy score median 4, IQR 2-6 vs 2, 2-4, p=0.02). Final diagnoses for LBBB-activations were acute coronary syndrome (39.2%), non-acute coronary syndrome cardiac chest pain (33.3%) and non-cardiac chest pain (27.5%). In appropriate LBBB-activations 1-year mortality and MACE were higher (23.8% vs 6.6%, p=0.002 and 28.6% vs 10.5%, p=0.007, respectively).
  
  
  CONCLUSIONS
  Our data suggests that despite its poor specificity for identifying acute coronary occlusion, LBBB should at the present time remain an activation criterion for PPCI and such patients should continue to be transferred to heart attack centres for assessment and treatment.
authors.affiliation: Department of Interventional Cardiology, Papworth Hospital, Papworth Everard, Cambridge, Cambridgeshire CB23 3RE, UK.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Brown
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Hoole
authors.forename: Liam M
authors.initials: LM
authors.lastname: McCormick
authors.forename: Matt
authors.initials: M
authors.lastname: Malone-Lee
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Cacciottolo
authors.forename: Peter M
authors.initials: PM
authors.lastname: Schofield
authors.forename: Nick E J
authors.initials: NE
authors.lastname: West
mesh_terms: D000208:Acute Disease; D000368:Aged; D002037:Bundle-Branch Block / Q000150:complications* / Q000453:epidemiology / Q000601:surgery; D017023:Coronary Angiography; D003328:Coronary Thrombosis / Q000150:complications* / Q000453:epidemiology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D062645:Percutaneous Coronary Intervention / Q000379:methods*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D006113:United Kingdom / Q000453:epidemiology