Which class of antiarrhythmic drugs were studied in the Cast Trial?

Which class of antiarrhythmic drugs were studied in the Cast Trial?

• A. Class I antiarrhythmics
• B. Class II antiarrhythmics
• C. Class III antiarrhythmics
• D. Class IV antiarrhythmics

Answer: (A)

The Cast Trial examined using sodium-channel blocking antiarrhythmics (Class I), specifically the Class IC drugs flecainide and encainide, to suppress frequent premature ventricular contractions in patients with ischemic heart disease. The study found that these drugs increased mortality due to proarrhythmia, so suppressing PVCs with Class I agents in this population was harmful rather than beneficial. The trial did not address Class II, III, or IV agents, which are why those classes aren’t the focus of Cast.

The Cast Trial examined using sodium-channel blocking antiarrhythmics (Class I), specifically the Class IC drugs flecainide and encainide, to suppress frequent premature ventricular contractions in patients with ischemic heart disease. The study found that these drugs increased mortality due to proarrhythmia, so suppressing PVCs with Class I agents in this population was harmful rather than beneficial. The trial did not address Class II, III, or IV agents, which are why those classes aren’t the focus of Cast.