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Cardiac Arrhythmia Pilot Study (CAPS)

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: October 28, 1999
Last Update Posted: March 17, 2014
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.
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
To compare the effectiveness of various drugs and drug combinations in suppressing complex ventricular arrhythmias, and to evaluate their safety.

Condition Intervention Phase
Arrhythmia Cardiovascular Diseases Heart Diseases Ventricular Arrhythmia Drug: encainide Drug: moricizine Drug: flecainide Drug: imipramine Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Masking: Double
Primary Purpose: Treatment

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: September 1982
Study Completion Date: September 1985
Detailed Description:


Epidemiologic studies had indicated that complex ventricular premature beats made an independent contribution to risk of sudden death in survivors of a myocardial infarction (MI), and did not appear to be merely a reflection of their association with relatively severe myocardial damage. The potential for reduction in mortality by identification and administration of drugs capable of safely suppressing ventricular arrhythmias was tremendous. In 1982, there was incomplete knowledge regarding which types of ventricular arrhythmias responded to various kinds of drugs. A pilot study of antiarrhythmic agents helped clarify this issue.

Numerous antiarrhythmic agents with differing pharmacologic properties and side effects had been shown to suppress ventricular arrhythmias. It had also been postulated that antiarrhythmics might raise an individual's threshold for experiencing ventricular fibrillation. There had been several published reports of large (at least l00 patients), long-term clinical trials of antiarrhythmic agents in post-MI patients. None of these had yielded statistically significant results using mortality as the response variable. This might have been due to incorrect drug selection, inadequate sample size, inappropriate choice of patients, or the lack of impact of arrhythmia treatment on mortality.

Due to incomplete knowledge as to which drug(s) and combinations of drugs were most effective, it was considered to be premature to undertake a full scale trial in 1981-1982. However, the public health problem was of sufficient magnitude to warrant a pilot study to learn more about the efficacy and safety of various antiarrhythmic drugs singly or in combination.

The protocol planning phase began in October l982. Patient recruitment started in July l983 and ended in the summer of 1985. Each patient was followed for one year.


Randomized, double-blind, fixed sample. A total of 502 patients were randomly assigned to 5 treatment groups consisting of encainide, ethmozine, flecainide, imipramine, and placebo.


Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Men and women. Patients had acute myocardial infarction and ventricular arrhythmias.
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00000504

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
OverallOfficial: Toshio Akiyama University of Rochester
OverallOfficial: Allan Barker Salt Lake Clinic Research Foundation
OverallOfficial: J. Bigger Columbia University
OverallOfficial: Robert Capone Rhode Island Hospital
OverallOfficial: Lawrence Griffith Johns Hopkins University
OverallOfficial: Craig Pratt Baylor College of Medicine
OverallOfficial: David Richardson Medical College of Virginia
OverallOfficial: William Rogers University of Alabama at Birmingham
OverallOfficial: Michael Sather V.A. Medical Center
OverallOfficial: Israel Stein Clinical Data, Inc
OverallOfficial: Pierre Theroux Montreal Heart Institute
OverallOfficial: Raymond Woosley Vanderbilt University Medical Center
  More Information


ClinicalTrials.gov Identifier: NCT00000504     History of Changes
Other Study ID Numbers: 23
First Submitted: October 27, 1999
First Posted: October 28, 1999
Last Update Posted: March 17, 2014
Last Verified: April 2012

Additional relevant MeSH terms:
Cardiovascular Diseases
Heart Diseases
Anti-Arrhythmia Agents
Voltage-Gated Sodium Channel Blockers
Sodium Channel Blockers
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Antidepressive Agents, Tricyclic
Antidepressive Agents
Psychotropic Drugs
Adrenergic Uptake Inhibitors
Neurotransmitter Uptake Inhibitors
Adrenergic Agents
Neurotransmitter Agents
Physiological Effects of Drugs