Multicenter Unsustained Tachycardia Trial (MUSTT)

BACKGROUND: Cardiac arrest (sudden cardiac death) occurs relatively frequently in asymptomatic patients who have had myocardial infarctions, have ejection fractions less than 40 percent, and non-sustained ventricular tachycardia. However, it is not possible to predict who will die suddenly or when cardiac arrest will occur. Current efforts to reduce sudden death in such long-term survivors of myocardial infarction or in patients with coronary disease have produced results that are not very encouraging. Such patients may feel quite well. They survived their myocardial infarction and may have slight or even moderate reduction of exercise ability, but by 'pacing' themselves, such patients can lead relatively normal lives. They may be aware of their arrhythmia because of short periods of palpitations which may only trouble them transiently. Consequently, this group of patients, many still in the prime of their lives, are at relatively high risk of dying suddenly. The multicenter trial may reveal the most effective treatment for such patients, the value of electrophysiologic studies in predicting who is most at risk of sudden cardiac death, and whether electrophysiologic studies can help select the best mode of treatment. The protocol for performing programmed stimulation and serial drug testing is designed to mirror those currently in use by many practicing electrophysiologists. DESIGN NARRATIVE: Randomized, non-blind. Patients were assigned to standard therapy or to an aggressive arm consisting of electrophysiologic-guided antiarrhythmic therapy. Patients in the aggressive arm whose ventricular tachycardia was suppressible or who were still inducible, but who were hemodynamically stable in ventricular tachycardia, were followed on drug therapy. Otherwise, patients in the aggressive arm received an implantable defibrillator. The primary endpoint was sudden cardiac death or cardiac arrest. Patients without inducible sustained ventricular tachycardia were followed in a registry. Recruitment ceased on October 31, 1996 after a recommendation from the DSMB. The study completion date listed in this record was obtained from the "End Date" entered in the NIH Query View Report (QVR).