Use of beta-blockers and effects on heart rate and blood pressure post-acute coronary syndromes: are we on target?
BACKGROUND
beta-blockers have been shown to benefit patients after myocardial infarction by decreasing mortality, sudden cardiac death, and reinfarction. Although beta-blockers are recommended for all patients with acute coronary syndromes (ACS) without contraindications, a target heart rate (HR) is recommended only for patients with unstable angina/non ST-elevation myocardial infarction. A contemporary series documenting trends in beta-blocker usage and achieved HR and blood pressures (BP) is not available. The study objectives were to monitor trends in HR and BP in relation to beta-blocker use in a contemporary series of patients with ACS.


METHODS
In this observational study, 300 consecutive patients with proven ACS had HR and BP values collected hourly from admission until hospital discharge and averaged at multiple intervals throughout hospital stay. Data on baseline demographic characteristics, beta-blocker doses, and titration schedules, procedures performed, cardiac regimens, concurrent medical issues, and contraindications to therapy were collected.


RESULTS
Only 5.3% achieved an average HR of 50 to 60 beat/min throughout the hospital stay. Overall, the average HR was 74 beat/min and average BP was 115/64 mm Hg. Admission daily doses of metoprolol averaged 58 mg compared to discharge daily doses of 88 mg; only 52% of patients had dosage increases.


CONCLUSIONS
Although effective levels of BP were maintained during hospitalization for an ACS, target HRs were generally not achieved. Future studies are needed to determine the relationship between treatment objectives and clinical outcomes in the present era of ACS management.
Herman
Michael
M
Division of Cardiovascular Medicine, UMass-Memorial Medical Center, Worcester, MA 01655, USA.
Donovan
Jennifer
J
Tran
Maichi
M
McKenna
Brigid
B
Gore
Joel M
JM
Goldberg
Robert J
RJ
Tighe
Dennis A
DA
D054058:Acute Coronary Syndrome / Q000188:drug therapy* / Q000503:physiopathology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000494:pharmacology* / Q000627:therapeutic use; D008875:Middle Aged
D000319:Adrenergic beta-Antagonists; D008790:Metoprolol