Background: Premature ventricular complexes (PVCs) are common and associated with worse outcomes in patients with heart failure. Class 1C antiarrhythmic drugs (AADs) effectively suppress PVCs, but guidelines currently restrict their use in structural heart disease.

Objective: This study aimed to assess the safety and efficacy of 1C AADs in patients with nonischemic cardiomyopathy (NICM) and implantable cardioverter-defibrillators (ICDs).

Methods: All patients with NICM and an ICD treated with flecainide or propafenone at the Hospital of the University of Pennsylvania between 2014 and 2022 were identified. PVC burden, left ventricular ejection fraction (LVEF) and biventricular pacing percentage were compared before and during 1C AAD treatment. Safety outcomes included sustained atrial and ventricular arrhythmias, heart failure admissions and death.

Results: We identified 34 patients, 23 receiving flecainide and 11 propafenone. Most patients (62%) had failed other AADs or catheter ablation (68%) prior to 1C AAD initiation. PVC burden decreased from 20±13% to 6±7% (p<0.001), LVEF increased from 33±9 to 37±10% (p=0.01) and biventricular pacing percentage increased from 85±9% to 93±7% (p=0.01). Sustained VT (2 vs 9 patients) and admissions for decompensated heart failure (2 vs 3 patients) decreased compared to the 12 months prior to 1C AAD initiation.

Conclusions: 1C AADs effectively suppressed PVCs in patients with NICM and ICDs, leading to increases in LVEF and biventricular pacing percentage. In this limited sample, their use was safe. Larger studies are needed to confirm the safety of this approach.

Editor-in-Chief
Kalyanam Shivkumar, MD, PhD, FACC
 
CME Editor
Kenneth A. Ellenbogen, MD, FACC

Author
Mahmoud Houmsse, MD, FACC

Important Dates
Date of Release: May 27, 2024
Term of Approval/Date of CME/MOC Expiration: May 26, 2025