COMMIT/CCS-2 

Title: Clopidogrel and Metoprolol in Myocardial Infarction (2005)

Metoprolol

P: 45852 patients within 24h of suspected acute MI

I: Metoprolol up to 15mg IV then 200mg po daily until discharge or up to 4 weeks in hospital (mean 15 days in survivors)

C: Matching placebo

O:

Primary outcomes:

  • Composite of death, reinfarction or cardiac arrest
  • Death from any cause during scheduled treatment period

Results:

  • No significant difference for both primary outcomes
  • For reinfarction: OR 0.82 (0.72-0.92, p=0.001) – 5 fewer per 1000
  • For ventricular fibrillation: OR 0.83 (0.75-0.93, p=0.001) – 5 fewer per 1000
  • For cardiogenic shock: OR 1.30 (1.19-1.41, p<0.00001) – 11 more per 1000 (mainly during days 0-1 on admission)
  • Overall effect on death, reinfarction, arrest or shock was significantly adverse during days 0-1 and significantly beneficial thereafter. There was substantial net hazard in hemodynamically unstable patients and moderate net benefit in those who were relatively stable (particularly after days 0-1)

Clinical Pearls/Take-home messages:

  • For MI, BB decreases risk for reinfarction and ventricular fibrillation
  • Caution when starting beta-blockers post-MI as increased risk for cardiogenic shock, especially during the initiation of BB
    • Ensure patients are euvolemic and hemodynamically unstable, prior to starting beta-blocker
  • Monitor for cardiogenic shock:
    • LOC, sweating, pale skin, increased HR, decreased BP, respiratory distress (tachypnea, hypoxemia), decrease in urine output