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Cardiac Arrhythmia Suppression Trial (CAST)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00000526
Recruitment Status : Completed
First Posted : October 28, 1999
Last Update Posted : May 6, 2016
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)

Tracking Information
First Submitted Date  ICMJE October 27, 1999
First Posted Date  ICMJE October 28, 1999
Last Update Posted Date May 6, 2016
Study Start Date  ICMJE August 1986
Primary Completion Date Not Provided
Current Primary Outcome Measures  ICMJE Not Provided
Original Primary Outcome Measures  ICMJE Not Provided
Change History
Current Secondary Outcome Measures  ICMJE Not Provided
Original Secondary Outcome Measures  ICMJE Not Provided
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE Cardiac Arrhythmia Suppression Trial (CAST)
Official Title  ICMJE Not Provided
Brief Summary To determine whether drug treatment of asymptomatic ventricular arrhythmias in post-myocardial infarction patients reduced the incidence of sudden cardiac death and total mortality.
Detailed Description


Each year over 400,000 people in the United States die suddenly of coronary heart disease. The majority have known coronary heart disease. Of these, the post-myocardial infarction population constitutes a large proportion. About 8 to 15 percent of patients who recover from an acute myocardial infarction die in the subsequent year. Half of these deaths are usually sudden, presumably due to arrhythmia. Advanced age, poor ventricular function, and presence of ventricular arrhythmias can identify post-MI patients at high risk of sudden cardiac death and all-cause mortality.

A number of clinical trials have evaluated whether acute or chronic anti-arrhythmic drug therapy can reduce mortality in post-MI patients. Of these, only the use of acute intravenous and long-term beta-blockers, independently and in combination, had been shown to reduce mortality. However, beta-blockers have many actions in addition to being anti-arrhythmic agents and it is possible that these other effects may have been particularly important in prolonging life.

None of the clinical trials of other antiarrhythmic drugs had shown significant benefits from treatment, and a number had even failed to show a positive trend. It was certainly possible that treatment of ventricular premature depolarizations, in itself, did not lead to a reduction in mortality, or even sudden death. The studies that had been done, however, had not adequately addressed the issue. Most of the studies were small and did not select patients on the basis of frequent ectopic beats. Moreover, appropriate drugs in optimal doses may not have been used, and adverse effects may well have outweighed any potential benefit. Poor compliance, perhaps due to adverse effects, may also have limited the opportunity for a beneficial outcome.

In an effort to address some of these points, the National Heart, Lung, and Blood Institute initiated the Cardiac Arrhythmia Pilot Study in 1982. The objectives were to assess: whether post-MI patients with documented ventricular arrhythmia could be identified and enrolled into a double-blind clinical trial; whether one or more drugs could be found to effectively and safely reduce ventricular premature depolarizations over a one-year period; whether dose-adjustment could be carried out, using ambulatory ECG's; and whether good patient compliance could be maintained. The Cardiac Arrhythmia Pilot Study, which enrolled 500 patients, evaluated four active drugs (encainide, ethmozine, flecainide, imipramine) against placebo. The study was too small to determine whether any of these drugs had an effect on mortality or major morbidity. The study was completed in July 1986.

The pilot study demonstrated that patient recruitment was feasible, that dose-adjustment could be accomplished, and that good compliance to the protocol could be achieved. Because of the encouraging results of the pilot study, the NHLBI conducted a full-scale trial.


Randomized, double-blind. Enrollment began in June 1987 when twenty-seven clinical centers began to randomize 4,400 post-myocardial infarction patients to placebo or treatment with encainide, flecainide, or moricizine. Prior to actual randomization, there was an open-label titration period to identify patients who responded to treatment. A total of 1,727 patients who responded were randomized: 1,455 to encainide, flecainide, or placebo, and 272 to moricizine or placebo. In April 1989, encainide and flecainide were discontinued because of increased total mortality and sudden arrhythmic death. CAST continued to compare moricizine to placebo in 1,300 patients for 18 months until August 1991 when the moricizine portion of the trial was stopped early because of excess deaths. The primary outcome variable in the full-scale trial was sudden cardiac death, with total mortality a secondary endpoint. Data analysis continued through March 1998.

Study Type  ICMJE Interventional
Study Phase  ICMJE Phase 3
Study Design  ICMJE Allocation: Randomized
Masking: Double
Primary Purpose: Prevention
Condition  ICMJE
  • Cardiovascular Diseases
  • Coronary Disease
  • Death, Sudden, Cardiac
  • Heart Arrest
  • Heart Diseases
  • Myocardial Infarction
  • Myocardial Ischemia
  • Ventricular Arrhythmia
Intervention  ICMJE
  • Drug: encainide
  • Drug: flecainide
  • Drug: moricizine
Study Arms  ICMJE Not Provided
Publications *

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Completed
Enrollment  ICMJE Not Provided
Original Enrollment  ICMJE Not Provided
Study Completion Date  ICMJE March 1998
Primary Completion Date Not Provided
Eligibility Criteria  ICMJE Men and women with ventricular premature depolarization six days to two years after the start of myocardial infarction.
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 18 Years to 75 Years   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE No
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE Not Provided
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT00000526
Other Study ID Numbers  ICMJE 45
Has Data Monitoring Committee Not Provided
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party Not Provided
Study Sponsor  ICMJE National Heart, Lung, and Blood Institute (NHLBI)
Collaborators  ICMJE Not Provided
Investigators  ICMJE
Investigator: Alfred Hallstrom University of Washington
PRS Account National Heart, Lung, and Blood Institute (NHLBI)
Verification Date August 2004

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP