Question: Do ß-blockers have an effect on the 30-day risk of major cardiovascular events in patients with or at risk of atherosclerotic disease undergoing noncardiac surgery?
Design: Randomized controlled trial.
Setting: Multicentre trial in 190 hospitals in 23 countries.
Patients: In total, 8351 patients with or at risk of atherosclerotic disease undergoing noncardiac surgery.
Intervention: Patients were randomly assigned by a computerized 24-hour phone service to receive extended-release metoprolol succinate 200 mg (n = 4174) or placebo (n = 4177). Treatment was started 2-4 hours before surgery and continued for 30 days.
Main outcome: Cardiovascular death, nonfatal myocardial infarction (MI) and nonfatal cardiac arrest.
Results: Of those randomized, 8331 (99.8%) patients completed the 30-day follow-up. Fewer patients in the metoprolol group than in the placebo group had an MI (176 [4.2%] v. 239 [5.7%] patients; hazard ratio [HR] 0.73, 95% confidence interval [CI] 0.60-0.089, p = 0.0017). However, there were more deaths in the metoprolol group than in the placebo group (129 [3.1%] v. 97 [2.3%] patients; HR 1.33, 95% CI 1.03-1.74, p = 0.0317). More patients in the metoprolol group than in the placebo group had a stroke (41 [1.0%] v. 19 [0.5%] patients; HR 2.17, 95% CI 1.26-3.74, p = 0.0053).
Conclusion: A perioperative ß-blocker regimen results in fewer MIs but is associated with an increased risk of stroke and perioperative death in patients with or at risk for atherosclerotic disease undergoing noncardiac surgery. Patients are unlikely to accept the risks associated with perioperative extended-release metoprolol use.