title: Left bundle branch block and cardiovascular morbidity and mortality in hypertensive patients with left ventricular hypertrophy: the Losartan Intervention For Endpoint Reduction in Hypertension study.
abstract: BACKGROUND
  Whether left bundle branch block is associated with cardiovascular events in hypertension with electrocardiographic left ventricular hypertrophy is unknown.
  
  
  METHODS
  Hypertensive patients with electrocardiographic-left ventricular hypertrophy were randomized to losartan-based or atenolol-based treatment and followed for 4.8 years in the losartan intervention for endpoint reduction in hypertension study. Cox regression models controlling for significant covariates assessed the association of left bundle branch block with cardiovascular events.
  
  
  RESULTS
  At baseline, 564 patients had left bundle branch block and 8567 patients did not. Left bundle branch block was associated with higher heart rate, electrocardiographic-left ventricular hypertrophy, and prior cardiovascular disease (all P < 0.005). In univariate Cox regression analysis, left bundle branch block was not associated with the composite endpoint, stroke, or myocardial infarction (all P > 0.05), and was associated with cardiovascular (8.3 versus 4.5%, P < 0.001) and all-cause mortality (12.1 versus 8.6%, P < 0.005). After adjusting for significant covariates Cox regression analyses showed that left bundle branch block was independently associated with 1.6-fold more cardiovascular death (95% confidence interval 1.12-2.27, P < 0.05), 1.7 fold more hospitalization for heart failure (95% confidence interval 1.15-2.56, P < 0.01), 3.5 fold more cardiovascular death within 1 h (95% confidence interval 1.89-6.63, P < 0.001), and 3.4 fold more cardiovascular death within 24 h (95% confidence interval 1.83-6.35, P < 0.001).
  
  
  CONCLUSIONS
  In hypertension with electrocardiographic-left ventricular hypertrophy, left bundle branch block identifies patients at increased risk of cardiovascular mortality, sudden cardiovascular death, and heart failure.
authors.affiliation: Department of Medicine, Weill Cornell Medical College, New York, NY 10021, USA.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Li
authors.forename: Björn
authors.initials: B
authors.lastname: Dahlöf
authors.forename: Peter M
authors.initials: PM
authors.lastname: Okin
authors.forename: Sverre E
authors.initials: SE
authors.lastname: Kjeldsen
authors.forename: Kristian
authors.initials: K
authors.lastname: Wachtell
authors.forename: Hans
authors.initials: H
authors.lastname: Ibsen
authors.forename: Markku S
authors.initials: MS
authors.lastname: Nieminen
authors.forename: Sverker
authors.initials: S
authors.lastname: Jern
authors.forename: Richard B
authors.initials: RB
authors.lastname: Devereux
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001262:Atenolol / Q000627:therapeutic use; D002037:Bundle-Branch Block / Q000150:complications / Q000175:diagnosis / Q000401:mortality*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000188:drug therapy / Q000401:mortality*; D017379:Hypertrophy, Left Ventricular / Q000150:complications / Q000188:drug therapy / Q000401:mortality*; D019808:Losartan / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011379:Prognosis
chemical_list: D000959:Antihypertensive Agents; D001262:Atenolol; D019808:Losartan