title: Beta-blockers and cardiovascular outcomes in dialysis patients: a cohort study in Ontario, Canada.
abstract: BACKGROUND
  Beta-blockers may be cardioprotective in patients receiving chronic dialysis. We examined cardiovascular outcomes among incident dialysis patients receiving beta-blocker therapy.
  
  
  METHODS
  We conducted a retrospective cohort study employing linked healthcare databases in Ontario, Canada. We studied all consecutive chronic dialysis patients aged≥66 years who initiated dialysis between 1 July 1991 and 31 July 2007. Patients were divided into three groups according to new medication use after the initiation of chronic dialysis. The three groups were patients initiated on beta-blockers, calcium channel blockers and statins only. Patients in the beta-blocker and calcium channel blocker groups could also be concurrently receiving a statin. The primary outcome was time to a composite endpoint of death, myocardial infarction, stroke or coronary revascularization.
  
  
  RESULTS
  There were a total of 1836 patients (504 beta-blocker, 570 calcium channel blocker and 762 statin-only users). Compared to statin-only use, beta-blocker use was not associated with improved cardiovascular outcomes [adjusted hazard ratio (aHR) 1.07, 95% confidence interval (CI) 0.92-1.23]. As expected, calcium channel blocker use was also not associated with improved cardiovascular outcomes (aHR 0.91, 95% CI 0.79-1.06). Among all subgroup analyses by beta-blocker attributes, only high-dose beta-blocker therapy was associated with better cardiovascular outcomes as compared to low-dose beta-blockers (aHR 0.50, 95% CI 0.29-0.88).
  
  
  CONCLUSIONS
  We observed no beneficial effect of beta-blocker use among patients receiving chronic dialysis relative to our comparator groups. Given current uncertainty around the cardioprotective benefits of beta-blockers in patients receiving dialysis, a large randomized clinical trial is warranted.
authors.affiliation: Department of Medicine, University of Western Ontario, London, Ontario, Canada.
authors.forename: Abhijat
authors.initials: A
authors.lastname: Kitchlu
authors.forename: Kristin
authors.initials: K
authors.lastname: Clemens
authors.forename: Tara
authors.initials: T
authors.lastname: Gomes
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Hackam
authors.forename: David N
authors.initials: DN
authors.lastname: Juurlink
authors.forename: Muhammad
authors.initials: M
authors.lastname: Mamdani
authors.forename: Michael
authors.initials: M
authors.lastname: Manno
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Oliver
authors.forename: Robert R
authors.initials: RR
authors.lastname: Quinn
authors.forename: Rita S
authors.initials: RS
authors.lastname: Suri
authors.forename: Ron
authors.initials: R
authors.lastname: Wald
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Yan
authors.forename: Amit X
authors.initials: AX
authors.lastname: Garg
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D000369:Aged, 80 and over; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D007676:Kidney Failure, Chronic / Q000150:complications*; D008297:Male; D009864:Ontario; D011379:Prognosis; D006435:Renal Dialysis / Q000009:adverse effects*; D012189:Retrospective Studies
chemical_list: D000319:Adrenergic beta-Antagonists; D002121:Calcium Channel Blockers; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors