Author + information
- Lionel H. Opie, MD, DPhil∗ ()
- ↵∗Hatter Institute for Cardiovascular Research in Africa, Department of Medicine, University of Cape Town and Groote Schuur Hospital, 7925 Cape Town, South Africa
The paper by Pizarro et al. (1) gives strong support to the concept of very early low-cost intravenous beta-blockade for primary percutaneous coronary intervention (pPCI) and makes metoprolol the agent of choice. When metoprolol was given to patients with acute myocardial infarction (AMI) in Killip class ≤II ST-segment elevation myocardial infarction undergoing pPCI, there were fewer heart failure admissions. The number needed to treat to avoid 1 implantable cardioverter-defibrillator was only 8. Unexpectedly, there was no indication of any side effects of beta-blockade. Were there really none?
In the COMMIT (Clopidogrel and Metoprolol in Myocardial Infarction Trial) study of 45,852 patients admitted to 1,250 hospitals within 24 h of suspected AMI, patients were randomly allocated metoprolol (up to 15 mg intravenous, then 200 mg oral daily; n = 22,929) or matching placebo (n = 22,923) (2). The use of early beta-blocker therapy in AMI reduced the risks of reinfarction and ventricular fibrillation, yet cardiogenic shock was a major side effect. Pizarro et al. (1) suggested starting beta-blocker therapy only when the hemodynamic condition had stabilized.
Yusuf (3) analyzed 28 trials involving approximately 27,500 patients during suspected early AMI. Overall, he concluded that intravenous plus oral beta-blockade reduced the risk for early death, reinfarction, and ventricular fibrillation by approximately 15% (3). He suggested that the reduction in mortality was greatest for those treated within 2 h of pain. The treated group had few side effects, namely reversible and nonfatal heart block and hypotension.
Thus in 2 large studies, beta-blockade had side-effects to which clinicians should be alerted when considering the use of beta-blockers for early AMI.
- American College of Cardiology Foundation
- Pizarro G.,
- Fernández-Friera L.,
- Fuster V.,
- et al.
- Chen Z.M.,
- Pan H.C.,
- Chen Y.P.,
- et al.