The use of beta-blockers in patients with new-onset coronary heart disease (CHD) is associated with a lower risk of cardiac events only in those who have had a recent myocardial infarction (MI), a study has shown.

The researchers examined the effectiveness of beta-blockers in preventing further cardiac events in patients with new onset coronary artery disease.

The trial enrolled 26,793 patients discharged after the index coronary event (acute coronary syndrome or coronary revascularisation) between 2000 and 2008 who did not use beta-blockers in the year before entry.

Of these, 19,843 patients had a beta-blocker commenced within seven days of discharge from their initial coronary event.

Over an average of 3.7 years’ follow-up, 6,968 patients had an MI or died. Beta-blocker therapy was associated with an adjusted hazard ratio (HR) for mortality of 0.90 (95% CI:0.84-0.96), and an adjusted HR for death or MI of 0.92 (95% CI:0.87-0.97).

The association between beta-blockers and outcomes differed significantly between patients with and without a recent MI; HR for death 0.85 vs 1.02 and HR for death or MI 0.87 vs 1.03.

Beta-blockers are often used as a first-line drug both in the management of suspected or established coronary disease and post-MI. Despite the usefulness of this class of drugs in the management of angina they are often used in asymptomatic patients with coronary disease in the belief that they will reduce the incidence of further coronary events. However, the effectiveness of beta-blockers in preventing cardiac events has been questioned for patients who have CHD without a prior MI.

The authors conclude that the use of beta-blockers in patients with new-onset CHD was associated with a lower risk of cardiac events but only among those patients with a recent MI.

Dr Peter Savill