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Studies Show Beta-Blockers Have No Mortality Benefit in Post-Heart Attack Patients
Beta-blockers have been a cornerstone in the treatment of heart attack survivors for more than 25 years. However, many of the data predate contemporary medical therapy, such as reperfusion, statins, and antiplatelet agents, and recent findings have called the role of beta-blockers into question.
Two new studies published in the American Journal of Medicine evaluated the traditional management of heart attack patients after their discharge from the hospital and in the light of changing medical treatment, as well as the effect of the discharge heart rate and conventional treatment with beta-blockers.
In the first study, researchers analyzed 60 randomized trials that evaluated beta-blockers in a total of 102,003 patients with myocardial infarction (MI). Fourteen studies involving 20,418 patients provided data on follow-up periods longer than 1 year. The trials were stratified into those that took place in the reperfusion era (more than 50% of patients undergoing reperfusion or receiving aspirin or a statin) and those that took place before the reperfusion era.
The researchers evaluated the effect of contemporary treatment status (reperfusion/aspirin/statin) on the association of beta-blocker use and outcomes in heart attack patients; the role of early intravenous beta-blocker therapy; and the required duration of beta-blocker use. They found that beta-blockers have no mortality benefit in the contemporary treatment of heart attacks.
“In patients undergoing contemporary treatment, our data support the short-term (30 days) use of beta-blockers to reduce recurrent heart attacks and angina, but this has to be weighed at the expense of an increase in heart failure, cardiogenic shock, and drug discontinuation, without prolonging life,” said lead investigator Sripal Bangalore, MD, MHA, of the New York University Langone Medical Center. “The guidelines should reconsider the strength of recommendations for beta-blockers post-myocardial infarction.”
In the second study, French researchers evaluated the determinants of the discharge heart rate in patients with acute coronary syndrome and assessed the effect of this heart rate on 5-year mortality in hospital survivors. During the past 20 years, there has been growing interest in the use of the heart rate as a marker for risk stratification in cardiovascular diseases and as a prognostic factor for global and cardiovascular mortality, the authors said. However, few data are available regarding the long-term effect of the discharge heart rate.
The discharge heart rate was recorded in more than 3,000 patients discharged over a 1-month period at 223 participating institutions in the French Registry of Acute ST Elevation or Non-ST-Elevation Myocardial Infarction (FAST-MI). The patients were followed for more than 5 years. The objective of FAST-MI was to evaluate practices for managing heart attacks (MIs) in “real life” conditions, and to measure their relationship with acute and long-term outcomes in patients admitted to coronary-care units for heart attack in France, regardless of the type of health care establishment to which the patients were admitted. An elevated ST segment seen on an electrocardiogram indicates that a relatively large amount of heart muscle damage has occurred, and is what gives this type of heart attack its name.
The patients’ heart rates were categorized into four groups: more than 60, 61–67, 68–75, and more than 75 beats per minute. A high heart rate was defined as more than 75 beats per minute. An analysis was performed at 1 year.
“We found several factors related to a high heart rate,” said senior investigator François Schiele, MD, PhD. “They included ST-elevation myocardial infarction, diabetes, chronic obstructive pulmonary disease, bleeding or transfusion during hospitalization, left ventricular dysfunction, renal dysfunction, and the prescription of beta-blockers at discharge. Women were also more likely to have a high heart rate.”
“We found that the discharge heart rate is significantly related to 1-year mortality, and that patients discharged with a high heart rate are at higher risk of death during the first year, irrespective of beta-blocker use,” Schiele added.
Source: EurekAlert; November 10, 2014.