The Cardiac Arrhythmia Suppression Trial (CAST) was a double-blind, randomized, controlled study designed to test the hypothesis that suppression of premature ventricular complexes (PVC) with class I antiarrhythmic agents after a myocardial infarction (MI) would reduce mortality.
[2] The publication of these results in 1991/92, in combination with large follow-up studies for drugs that had not been tested in CAST, led to a paradigm shift in the treatment of MI patients.
[4] This included 1) patients enrolled within 4 to 90 days of a previous MI, 2) a left ventricular ejection fraction lower than 40%, 3) prior to enrollment, suppression of PVCs had occurred with the drugs (vs. placebo) using a double-blinded design, and 4) patients having more serious arrhythmias would also be included.
[citation needed] The drugs used (encainide, flecainide, and moracizine) successfully reduced the amount of PVCs, but led to more arrhythmia-related deaths.
Within about two years after enrollment, encainide and flecainide were discontinued because of increased mortality and sudden cardiac death.