Abstract 5590: Are Beta-blockers Underdosed Following Acute Myocardial Infarction?
Quality improvement (QI) programs have increased the prescription of beta-blockers (BB) following myocardial infarction (MI) but whether patients are prescribed effective doses is unknown. Purpose To evaluate whether target doses of BB are achieved post-MI.
Methods The Pacemaker and Beta-Blocker Therapy After MI (PACE-MI) registry recorded data from 1304 patients with acute MI from 23 hospitals in the US and Canada in 2007– 8. Clinical characteristics, and discharge medications, were collected. BB dose information was available in 731 patients at 3-week follow-up (FU). BB dosages achieved are displayed as % of target doses (i.e. metoprolol 200 mg/day) shown to be effective in clinical trials.
Results In hospital mortality was 4.4%. Mean age for patients discharged was 64 ± 29 years, with 69% male, 32% diabetes, 67% hypertension, and 52% hypercholesterolemia; 42% had an ST elevation MI, 55% underwent PCI and 9% lytic therapy. Mean ejection fraction was 48 ± 12%. At discharge, 88% were on aspirin, 84% on a statin and 91% on BB - 71% were discharged on metoprolol and 29% on other BBs. At 3-week FU, 77% had no BB dose change; 11% had a dose increase, 11% had a decrease in dose. Figure⇓ shows distribution of BB doses at 3-week FU. Only 11% achieved target dose; 43% achieved ≥50% of target dose. Hypertension was a predictor for higher dose (p<0.001). PCI was a predictor for lower dose (p=0.014).
Conclusion The PACE-MI registry confirms that BB utilization rates following MI are excellent, but shows a suboptimal rate of attainment of target doses within the first 3 weeks following MI. This represents an opportunity for QI in the care of patients who have suffered a MI and are transitioning to outpatient care.