Post-MI Beta-Blocker Benefit Appears to Shrink Over Time in Patients Without Heart Failure

By Reuters Staff

NEW YORK - Extending beta-blocker treatment for longer than a year after acute myocardial infarction (MI) in patients without heart failure or left ventricular dysfunction may not be beneficial, new findings suggest.

Patients who began taking beta-blockers within 48 hours of hospital admission had reduced 30-day mortality, Dr. Etienne Puymirat of the Hopital Europeen Georges Pompidou in Paris and colleagues found. But stopping the drugs after one year was not associated with increased mortality at five years.

"These observations suggest a progressively decreasing benefit of beta blocker treatment over time," the team writes in The BMJ, online September 20.

Most patients with acute MI begin taking beta-blockers at discharge and continue to do so for years, the researchers note, but the role of these drugs in patients without heart failure and with no left ventricular dysfunction is controversial.

Most studies on long-term beta-blocker use after acute MI were done long before widespread use of reperfusion therapy and secondary prevention drugs, Dr. Puymirat and colleagues add.

To investigate whether long-term beta-blocker use may still be beneficial in the current treatment era, the researchers looked at data from the French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction (FAST-MI) through the end of 2005 on 2,679 patients with acute MI without heart failure or left ventricular dysfunction.

Seventy-seven percent of patients began taking beta blockers within 48 hours of admission, 80% received a prescription at discharge, and 89% of patients alive at one year were still on beta-blockers.

Patients who took early beta blockers had significantly lower 30-day mortality (adjusted hazard ratio, 0.46). Patients prescribed beta-blockers at discharge did not have significantly lower one-year mortality, however (HR, 0.77); similarly, there was no decrease in five-year mortality among those who continued taking the drugs at one year (HR, 1.19).

Meanwhile, patients who had continued taking statins at one year had significantly lower five-year mortality (HR, 0.42) than those who stopped taking the drugs.

"These findings question the utility of prolonged beta blocker treatment after acute myocardial infarction in patients without heart failure or left ventricular dysfunction," Dr. Puymirat and colleagues conclude.

Dr. Puymirat did not respond to an interview request by press time.

SOURCE: https://bit.ly/2cI0Dfg

BMJ 2016.

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