MORTALITY of haemodialysis patients varies depending on the beta-blocker taken, suggests results of a new study from the University of North Carolina, Chapel Hill, North Carolina, USA. In the USA, approximately 80% of beta-blockers prescribed to haemodialysis patients are either metoprolol or carvedilol; these are two agents with notable pharmacologic and pharmacokinetic differences. Despite this, until now, there have been little data available to assess their comparative safety and efficacy.
Researchers from the University of North Carolina performed a retrospective analysis of 27,064 Medicare patients who began haemodialysis from 2007–2012. Of these patients, 64.7% were prescribed metoprolol and 35.3% were prescribed carvedilol; both groups were compared for the 1-year outcomes of all-cause mortality, cardiovascular mortality, and intradialytic hypertension, after adjusting for demographic, clinical, laboratory, and dialysis treatment covariates.
The groups proved highly comparable, but carvedilol was found to perform worse than metoprolol in both all-cause mortality per 1,000 person-years (225.1 versus 195.8, respectively; adjusted hazard ratio: 1.08) and cardiovascular mortality per 1,000 person-years (108.3 versus 85.1; adjusted hazard ratio: 1.18). While subgroup analyses revealed similar mortality differences for major indications for beta-blocker therapy (hypertension, atrial fibrillation, heart failure, and recent myocardial infarction), carvedilol was also shown to be associated with a higher rate of intradialytic hypertension than metoprolol (57.5 versus 55.2 incidences per 1,000 person-treatments, respectively; adjusted incident rate ratio: 1.10).
These results represent the first step towards a more complete comparison of these commonly prescribed drugs; definitive randomised trials are required to validate the findings. The authors hope that this analysis will provide practitioners with a greater insight when selecting beta-blockers and encourage physicians to consider the possible adverse haemodynamic effects of carvedilol when prescribing to patients.
