Patients treated with a lower dosage of beta-blockers following their myocardial infarction survived at the same rate, or even better rates, than patients on the high doses.
More precisely, the patients who received one-fourth of the recommended dose of medicine had up to a 20 to 25% decrease in mortality compared to the full dose group.
The overwhelming majority of myocardial infarction patients are sent home from the hospital with a prescription for beta-blockers. Beta-blockers are known to prevent a future heart attack, and they do this by inhibiting the effects of adrenaline on the heart, reducing irregular heartbeats, and generally helping to prevent organ failure.
Beta-blockers have a few side effects; these include drowsiness and fatigue, and, in rare cases, impotence, hallucinations, and memory loss.
In OBTAIN ( Outcomes of Beta-Blocker Therapy After Myocardial Infarction ) trial, researchers at Northwestern University ( Evanston, Illinois, U.S. ) examined data from 6,682 patients. All had experienced a myocardial infarction and about 90% were currently taking beta-blockers.
The research team discovered all the patients on beta-blockers survived longer than those who did not receive the drugs.
The raw figures from OBTAIN also included this breakdown: among the patients receiving a full dose, 14.7% died within two years; among those receiving half a dose, 12.9% died; among those receiving a quarter dose, 9.5% died; and among those receiving one-eighth dose, 11.5% died.
After analyzing this raw data, the researchers noted higher doses were not associated with better outcome.
Researchers believes more study is needed to determine exactly which dosage strength would benefit most patients. ( Xagena )
Source: Journal of the American College of Cardiology, 2015