Abstract 5589: Patterns of Use of Acute (< 24 hrs) Beta-Blocker Therapy in High-Risk Patients with Acute MI: Results from the ACC NCDR ACTION Registry
Background: Early use of beta-blockers (BB) is a quality indicator for the treatment of patients (pts) with ST-segment elevation (STEMI) and non-ST-segment myocardial infarction (NSTEMI), despite limited randomized clinical trials data. However, data from the recent COMMIT trial found an early hazard with BBs in this setting, especially for pts with high-risk features.
Methods: We examined acute (<24 hours) BB use in 50,517 pts with STEMI and NSTEMI included in the ACC NCDR ACTION registry (275 US hospitals) between Jan 2007 and Dec 2007. Pts with contraindications to BBs (13% STEMI, 12% NSTEMI), had missing data (3% STEMI, 4% NSTEMI), or received BB >24 hrs (<1.3% for each group) were excluded. We analyzed the use and impact of BB stratified by variables associated with increased risk for shock after BB use as specified by the recent ACC/AHA 2007 guidelines update: age >70, symptoms >12 hrs (STEMI pts), systolic blood pressure >120 mmHg, and heart rate <110 bpm.
Results: Among the analysis population, 96% of STEMI and 93% of NSTEMI pts received early BBs. CHF at presentation was found in 11% of STEMI and 20% of NSTEMI pts (TABLE⇓). At least 1 high risk variable (low BP, high heart rate, age>70, symptoms ≥12 hrs) was found in 51% of STEMI and 56% of NSTEMI pts, of whom 94% and 92%, respectively, received BBs within 24 hours. Complications, including mortality, were significantly lower in pts who received acute BBs.
Conclusions: The majority of STEMI and NSTEMI pts had at least 1 high risk feature for developing cardiogenic shock, but most pts (>90%) received early BBs. Despite this, pts who received BBs did not have more complications, including shock, and had a lower mortality. These results suggest that the recent AHA/ACC BB guidelines for acute BB use update may be too restrictive, as physicians appear to be able to appropriately determine who can safely receive acute BBs.