Beta-Blocker Heart Attack Trial (BHAT)
Condition: Arrhythmia; Cardiovascular Diseases; Coronary Disease; Death, Sudden, Cardiac; Heart Diseases; Myocardial Infarction; Myocardial Ischemia; Ventricular Fibrillation
MeSH terms: Cardiovascular Diseases; Myocardial Infarction; Coronary Disease; Myocardial Ischemia; Ventricular Fibrillation; Death, Sudden, Cardiac; Death, Sudden
Study type: Interventional
Phase: Phase 3

Summary: 
      To determine whether the regular administration of the beta-blocker drug propranolol to
      people who had had at least one documented myocardial infarction would result in a
      significant reduction of mortality from all causes over the follow-up period. Eligible
      volunteer patients were recruited to participate in a double-blind clinical trial within 21
      days after the onset of the acute event. One-half of the patients were randomly assigned to a
      beta-blocking drug (propranolol) and one-half to a placebo. The trial also evaluated the
      effect of propranolol on incidences of coronary heart disease mortality, sudden cardiac
      death, and nonfatal myocardial infarction plus coronary heart disease mortality in persons
      with documented previous myocardial infarction.
    

Detailed description: 
      BACKGROUND:

      Survivors of a documented myocardial infarction are recognized as having a high risk of dying
      relative to the general population. Serious arrhythmias, occurring with or without evidence
      of new infarction, are a common cause of death in this population. Theoretically, an agent
      which (1) can block the sympathetic nervous activity thought to be involved in precipitating
      sudden death and (2) has non-neurogenic antiarrhythmic properties would be of value to people
      with coronary heart disease. Propranolol, like other beta- blocking agents, has these as well
      as other properties and therefore might be expected to prevent or retard complications of
      coronary heart disease such as serious arrhythmias. This would be reflected in a decrease in
      mortality due to coronary heart disease.

      A workshop on chronic antiarrhythmic therapy reviewed contemporary experimental data and
      clinical practice and recommended that a clinical trial be undertaken to clearly show the
      effects of beta-blocking drugs on mortality. Subsequently, such a trial was approved by the
      Clinical Applications and Prevention Advisory Committee, by the Cardiology Advisory
      Committee, and by the National Heart, Lung, and Blood Advisory Council.

      The study protocol was reviewed in February 1978 and recommended for approval by the
      policy-data monitoring board and ad hoc members. The protocol was approved by the Director of
      NHLBI in March 1978. Recruitment started on June 19, 1978, and ended in October 1980. A total
      of 3,837 patients were randomized. Units which participated in the trial included 32 clinical
      centers, an EKG center, a central laboratory, a coordinating center, a 1-hour ambulatory ECG
      center, a 24-hour ambulatory EKG center, and an EKG tape quality control center.

      DESIGN NARRATIVE:

      A randomized, double-blind design with single experimental and control groups. Patients were
      recruited while in the hospital for an acute myocardial infarction and were enrolled in the
      study before discharge. Eligible patients fulfilled the study definition of an acute
      myocardial infarction. The diagnosis was based either on electrocardiographic records showing
      evolving QRS segment changes or on ST segment and T wave changes together with enzyme changes
      and appropriate clinical history. One-half of the patients were placed on therapy using a
      beta-blocking drug (propranolol). The other half received a placebo. The prescribed
      maintenance dosage of propranolol was either l80 or 240 mgs/day, depending upon serum drug
      levels. Intervention duration averaged 25 months.

      The study completion date listed in this record was obtained from the "Completed Date"
      entered in the Query View Report System (QVR).
    

Intervention name(s): propranolol
Intervention type(s): Drug
Intervention MeSH terms: Propranolol
Allocation: Randomized
Masking: Double
Primary purpose: Prevention