Initiation and outcomes with Class Ic antiarrhythmic drug therapy

Xu Gao; Avirup Guha; Benjamin Buck; Dilesh Patel; Melissa J Snider; Michael Boyd; Muhammad Afzal; Auroa Badin; Hemant Godara; Zhenguo Liu; Jaret Tyler; Raul Weiss; Steven Kalbfleisch; John Hummel; Ralph Augostini; Mahmoud Houmsse; Emile G Daoud

doi:10.1016/j.ipej.2017.12.001

Initiation and outcomes with Class Ic antiarrhythmic drug therapy

Indian Pacing Electrophysiol J. 2018 Mar-Apr;18(2):68-72. doi: 10.1016/j.ipej.2017.12.001. Epub 2017 Dec 7.

Authors

Xu Gao¹, Avirup Guha², Benjamin Buck¹, Dilesh Patel², Melissa J Snider², Michael Boyd², Muhammad Afzal², Auroa Badin², Hemant Godara², Zhenguo Liu², Jaret Tyler², Raul Weiss², Steven Kalbfleisch², John Hummel², Ralph Augostini², Mahmoud Houmsse², Emile G Daoud³

Affiliations

¹ Ohio State University Wexner Medical Center, Department of Internal Medicine, USA.
² Ohio State University Wexner Medical Center, Division of Cardiovascular Medicine, USA.
³ Ohio State University Wexner Medical Center, Division of Cardiovascular Medicine, USA. Electronic address: emile.daoud@osumc.edu.

Abstract

Background: Expert opinion recommends performing exercise testing with initiation of Class Ic antiarrhythmic medication.

Objective: To evaluate the rate and reason for discontinuation of Ic agent within the first year of follow up, with particular attention to rate of proarrhythmia and the value of routine treadmill testing.

Methods: This is a single center retrospective cohort study including consecutive patients with atrial arrhythmias who were initiated on a Class Ic agent from 2011 to 2016. Data was collated from chart review and pharmacy database.

Results: The study population included 300 patients (55% male, mean age 61; mean ejection fraction, 56%) started on flecainide (n = 153; 51%) and propafenone (n = 147; 49%). Drug initiation was completed while hospitalized on telemetry and the staff electrophysiologists directed dosing. There was one proarrhythmic event during initiation (0.3%). The primary reason for not being discharged on Ic agent was due to detection of proarrhythmia (n = 15) or ischemia (n = 1) with treadmill testing (5.3%). Exercise testing was the single significant variable to affect the decision to discontinue Ic drug, p < 0.0001 (95% CI: 1.89-6.08%). During follow up, the primary reason for discontinuation of Ic agent was lack of efficacy, 32%.

Conclusions: With proper screening, initiation of Class Ic agent is associated with very low rate of proarrhythmia. Treadmill testing is of incremental value and should be completed in all patients after loading Class Ic antiarrhythmic.

Keywords: Antiarrhythmic medication; Atrial fibrillation; Exercise stress testing; Flecainide; Proarrhythmia; Propafenone.