Intravenous β-blockers for patients undergoing primary percutaneous coronary intervention: A meta-analysis of randomized trials.

BACKGROUND: The efficacy and safety of intravenous β-blockers in patients with ST elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI) are not well known.

METHODS: Electronic databases were searched for randomized trials that compared intravenous β-blocker use with routine care or placebo in patients with STEMI undergoing primary PCI. Summary estimates risk ratios (RR) were constructed using DerSimonian and Laird model.

RESULTS: Four randomized trials with 1149 Killip class I or II STEMI patients were included. Intravenous β-blockers were associated with a reduction in the risk of ventricular arrhythmias during hospitalization (RR 0.42, 95% confidence interval [CI] 0.26-0.69, P=0.001). The risk of cardiogenic shock (RR 0.78, 95% CI 0.31-1.97, P=0.61), bradycardia (RR 1.54, 95% CI 0.35-6.81, P=0.57), all-cause mortality (RR 0.71, 95% CI 0.19-3.17, P=0.72), and cardiovascular mortality (RR 0.93, 95% CI 0.35-2.48, P=0.88) during hospitalization was similar in both groups. There was a trend towards a lower risk of future heart failure hospitalizations with intravenous β-blockers (RR 0.32, 95% CI 0.10-1.05, P=0.06).

CONCLUSION: Intravenous β-blockers, in STEMI patients (Killip class I or II) undergoing primary PCI, appear to be safe. Intravenous β-blockers were associated with a reduced risk of ventricular arrhythmias. Due to the small number of patients, the impact on other outcomes could not be determined. Therefore, future trials are recommended to establish the efficacy of intravenous β-blockers in primary PCI.