title: Comparative effectiveness of individual angiotensin receptor blockers on risk of mortality in patients with chronic heart failure.
abstract: OBJECTIVE
  There is little evidence on comparative effectiveness of individual angiotensin receptor blockers (ARBs) in patients with chronic heart failure (CHF). This study compared four ARBs in reducing risk of mortality in clinical practice.
  
  
  METHODS
  A retrospective analysis was conducted on a national sample of patients diagnosed with CHF from 1 October 1996 to 30 September 2002 identified from Veterans Affairs electronic medical records, with supplemental clinical data obtained from chart review. After excluding patients with exposure to ARBs within the previous 6 months, four treatment groups were defined based on initial use of candesartan, valsartan, losartan, and irbesartan between the index date (1 October 2000) and the study end date (30 September 2002). Time to death was measured concurrently during that period. A marginal structural model controlled for sociodemographic factors, comorbidities, comedications, disease severity (left ventricular ejection fraction), and potential time-varying confounding affected by previous treatment (hospitalization). Propensity scores derived from a multinomial logistic regression were used as inverse probability of treatment weights in a generalized estimating equation to estimate causal effects.
  
  
  RESULTS
  Among the 1536 patients identified on ARB therapy, irbesartan was most frequently used (55.21%), followed by losartan (21.74%), candesartan (15.23%), and valsartan (7.81%). When compared with losartan, after adjusting for time-varying hospitalization in marginal structural model, candesartan (OR = 0.79, 95%CI = 0.42-1.50), irbesartan (OR = 1.17, 95%CI = 0.72-1.90), and valsartan (OR =  0.98, 95%CI = 0.45-2.14) were found to have similar effectiveness in reducing mortality in CHF patients.
  
  
  CONCLUSIONS
  Effectiveness of ARBs in reducing mortality is similar in patients with CHF in everyday clinical practice.
authors.affiliation: Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Rishi J
authors.initials: RJ
authors.lastname: Desai
authors.forename: Carol M
authors.initials: CM
authors.lastname: Ashton
authors.forename: Anita
authors.initials: A
authors.lastname: Deswal
authors.forename: Robert O
authors.initials: RO
authors.lastname: Morgan
authors.forename: Hemalkumar B
authors.initials: HB
authors.lastname: Mehta
authors.forename: Hua
authors.initials: H
authors.lastname: Chen
authors.forename: Rajender R
authors.initials: RR
authors.lastname: Aparasu
authors.forename: Michael L
authors.initials: ML
authors.lastname: Johnson
mesh_terms: D000368:Aged; D057911:Angiotensin Receptor Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D001562:Benzimidazoles / Q000008:administration & dosage / Q000627:therapeutic use*; D001713:Biphenyl Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D002908:Chronic Disease; D015986:Confounding Factors, Epidemiologic; D057286:Electronic Health Records; D005260:Female; D006333:Heart Failure / Q000188:drug therapy / Q000401:mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D000077405:Irbesartan; D019808:Losartan / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008961:Models, Structural; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D013777:Tetrazoles / Q000008:administration & dosage / Q000627:therapeutic use*; D016896:Treatment Outcome; D014481:United States; D014633:Valine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000068756:Valsartan
chemical_list: D057911:Angiotensin Receptor Antagonists; D001562:Benzimidazoles; D001713:Biphenyl Compounds; D013777:Tetrazoles; D000068756:Valsartan; D014633:Valine; D000077405:Irbesartan; D019808:Losartan; C081643:candesartan