Beta-Blocker Therapy Early After Myocardial Infarction: A Comparison Between Medication at Hospital Discharge and Subsequent Pharmacy-Dispensed Medication

BACKGROUND Beta-blocker (BB) therapy after myocardial infarction (MI) reduces all-cause mortality. OBJECTIVE The aim of this study was to investigate BB dosing patterns and compliance following MI. METHODS Using medical patient files and nationwide databases, we identified 100 patients who were discharged following MI in 2012 from Aarhus University Hospital, Denmark, and subsequently redeemed one or more BB prescriptions within 6 months. We obtained information about all BB medication prescribed at discharge and all BB prescriptions redeemed until 31 December 2013. Daily BB doses were computed as percentages of the target doses used in clinical trials documenting the efficacy of BBs after MI. Four dose groups were defined: ≤12.5, >12.5-25, >25-50, and >50 % of target dose. The proportion of patients in each dose group was ascertained at and following discharge, as was the proportion that changed dose group following discharge. RESULTS The median study period was 400 days (interquartile range [IQR] 318-486 days). At discharge, 8 % of daily doses were >50 % of target dose while 80 % were ≤25 % of target dose. At first prescription redemption, 71.7 % of patients moved to a higher dose group (median dose change = 33.4 % [IQR 2.0-115.1]). Still, comparing final daily doses to discharge doses, 40.2 % did not change dose group (median dose change -5.7 % [IQR -18.0 to 4.2]). Only 31.5 % reached a final daily dose >50 % of target dose. CONCLUSIONS Target dose BB treatment was infrequently achieved at discharge following MI. Despite dose up-titration early after discharge, most patients did not receive target dose BB treatment approximately 1 year following MI.