Coronary Artery Bypass Graft (CABG) Patch Trial

To test the hypothesis that implantable cardioverter defibrillator (ICD) therapy will improve survival in coronary heart disease patients at high risk of death, especially arrhythmic death.

BACKGROUND:

Management strategies are urgently needed for the problem of sudden cardiac death, the most common single, non-accidental cause of death in adults in North America. Many consider that the problem of sudden cardiac death has reached epidemic proportions. Contemporary prophylactic management of sudden cardiac death includes identification of high risk populations, based on underlying structural heart disease, degree of left ventricular dysfunction, and evidence of a ventricular arrhythmia propensity. Populations with the highest sudden death cardiac risk, notably those patients resuscitated from spontaneous episodes of sustained ventricular tachyarrhythmias, have been used as test populations for the development of effective prophylactic approaches. However, in such populations, ethical considerations have precluded the use of untreated control groups. Furthermore, such patients comprise only a small proportion of the total patient population that could benefit from an effective prophylactic strategy. The largest 'at-risk' group are those patients with coronary artery disease and depressed left ventricular function who have, but have not yet expressed, a ventricular tachyarrhythmia propensity. The major advantages of a controlled trial of prophylactic therapy in the latter population are evaluation of sudden death prophylaxis in the larger 'at-risk' population and the opportunity to do so with an untreated control group. The 'window of opportunity' for such comparisons has been closed in resuscitated patients for some time and is in danger of closing in the larger population. The total absence of controlled efficacy data for ICD use despite 30,000 implanted units of this expensive technology argues strongly for the timely acquisition of controlled data in the larger population before the therapy is embraced any further.

DESIGN NARRATIVE:

Randomized, non-blind. Patients were randomized during surgery for coronary artery bypass graft to receive ICD or not, and followed and censored at 42 months at 35 centers. The primary endpoint was all-cause mortality. The trial described morbidity of ICD treatment, evaluated the effect of ICD therapy on quality of life, and compared health care costs of ICD treatment to those in the control group. Anti-arrhythmic treatment of unsustained arrhythmia was prohibited; anti-arrhythmic drug use, when indicated, was documented; and aspirin was prescribed unless contraindications existed. Recruitment was extended through December 1995 in order to accrue 900 patients, instead of the original 800 projected. As of February 1996, 900 patients had been recruited. In April 1997, the DSMB recommended that the trial be stopped because there was sufficient evidence to conclude that there was no difference between the treatment and control groups. Follow-up was extended for two years beyond the original termination date.

The study completion date listed in this record was obtained from the "End Date" entered in the old format Protocol Registration and Results System (PRS).

Eligibility Criteria:
Men and women, up to age 80, with a left ventricular ejection fraction less than .36 and an abnormal signal averaged electrocardiogram.