Patterns of use and potential impact of early beta-blocker therapy in non-ST-elevation myocardial infarction with and without heart failure: the Global Registry of Acute Coronary Events.

BACKGROUND: Early beta-blocker (BB) therapy improves outcomes in ST-segment elevation myocardial infarction; however, limited data are available on its early use and its impact in non-ST-segment elevation myocardial infarction (NSTEMI).
METHODS: We evaluated data from 7106 patients with NSTEMI, without contraindications to BBs, enrolled in the Global Registry of Acute Coronary Events between April 1999 and September 2004. Baseline characteristics, management, and outcomes were analyzed according to the use of oral (+/-intravenous) BB within 24 hours of presentation. Multivariable analysis was conducted adjusting for comorbidities using the Global Registry of Acute Coronary Events risk model (c statistic 0.83).
RESULTS: Beta-blocker therapy was initiated within the first 24 hours in 76% of patients with NSTEMI (79% with Killip class I vs 62% with class II/III; P < .001). Failure to initiate BBs within the first 24 hours was associated with lower rates of subsequent BB therapy (P < .001) and other evidence-based therapies. Early BB therapy was correlated with lower hospital mortality for NSTEMI patients (OR 0.58, 95% CI 0.42-0.81) and for those with Killip class II/III (OR 0.39, 95% CI 0.23-0.68) with a trend toward lower mortality in the Killip class I group (OR 0.77, 95% CI 0.49-1.21). At 6 months postdischarge, early BB use was associated with lower mortality in NSTEMI patients (OR 0.75, 95% CI 0.56-0.997) with a trend toward lower mortality in patients with Killip class I or II/III.
CONCLUSIONS: Many eligible patients do not receive early BB therapy. Treatment with early BBs may have a beneficial impact on hospital and 6-month mortality in all patients, including those presenting with heart failure.