Beta blockers (long-term use post myocardial infarction)

• long-term use of beta-blockers reduces mortality in patients who have had a myocardial infarction (evidence from a meta-analysis of randomised controlled trials)
• a beta blocker is recommended for all people following myocardial infarction unless there are contraindications. The evidence for beta blockade is strongest for those people with a large myocardial infarction, or infarction complicated by heart failure or ventricular arrhythmias (1)
• a systematic review concluded that, with a moderate-quality of evidence, beta-blockers for suspected or diagnosed acute myocardial infarction probably reduce the short-term risk of myocardial infarction during follow up and the long-term risk of all-cause mortality and cardiovascular mortality. Nevertheless, it is most likely that beta-blockers have little or no effect on the short-term risk of all-cause mortality and cardiovascular mortality (2)
  
  
• what about if a patient has normal left ventricular function:
  • ICE have issued guidance as to the use of beta blockers post myocardial infarction (3):  
    • continue a beta-blocker indefinitely in people with left ventricular systolic dysfunction
      
      
    • offer all people who have had an MI more than 12 months ago, who have left ventricular systolic dysfunction, a beta-blocker whether or not they have symptoms
      
      
    • do not offer people without left ventricular systolic dysfunction or heart failure, who have had an MI more than 12 months ago, treatment with a beta-blocker unless there is an additional clinical indication for a beta-blocker

Reference:

1. BS2: Joint British Societies' guidelines on prevention of cardiovascular disease in clinical practice. Heart 2005; 91 (Supp 5)
2. Safi S et al. Beta-blockers for suspected or diagnosed acute myocardial infarction. Cochrane Database Syst. Rev. December 2019.
3. NICE (2013). Secondary prevention in primary and secondary care for patients following a myocardial infarction