Ranolazine Added to Amiodarone Facilitates Earlier Conversion of Atrial Fibrillation Compared to Amiodarone-Only Therapy.
BACKGROUND
Amiodarone (AMIO) is for many years effectively used to control ventricular rate during atrial fibrillation (AF) and to convert it into sinus rhythm. However, due to its delayed onset of action, ranolazine (RAN), a new antianginal agent with atrial-selective electrophysiologic properties, has recently been attempted as add-on therapy with AMIO to facilitate AF conversion.


METHODS
To establish the role of this combination therapy, we enrolled 173 consecutive patients (68 ± 10 years, 54% male) with recent-onset (<48-hour duration) AF who were eligible for pharmacologic cardioversion. Patients were randomized to intravenous AMIO (loading dose 5 mg/kg in 1 hour followed by 50 mg/h; n = 81), or AMIO plus a single oral dose of RAN 1 g (n = 92).


RESULTS
Mean left atrial diameter did not significantly differ between groups, AMIO and AMIO + RAN (4.2 ± 0.5 cm vs 4.1 ± 0.4 cm, P = 0.18). The AMIO + RAN group compared with the AMIO-only group showed significantly shorter time to conversion (8.6 ± 2.8 hours vs 19.4 ± 4.4 hours, P < 0.0001) and higher conversion rate at 24 hours (98% vs 58%, P < 0.001). Left ventricular ejection fraction did not markedly vary between the two groups and ranged within moderately reduced values. No serious clinically evident adverse effects were observed in any of the patients receiving either AMIO or the combination treatment.


CONCLUSIONS
Our data demonstrate faster sinus rhythm restoration and enhanced conversion rate of AF after AMIO plus RAN in patients with preserved ejection fraction and left atrial size, implicating a synergistic effect of the two agents.
Department of Cardiology at University Hospital of Larissa, Larissa, Greece.
Nikos
N
Tsanaxidis
Department of Physiology, Medical School of Larissa, University of Thessaly, Larissa, Greece.
Isaac
I
Aidonidis
Department of Physiology, Medical School of Larissa, University of Thessaly, Larissa, Greece.
Apostolia
A
Hatziefthimiou
Division of Internal Medicine and Experimental Medicine, Department of Medicine, McGill University Health Centre, Canada.
Stella S
SS
Daskalopoulou
Department of Cardiology at University Hospital of Larissa, Larissa, Greece.
Grigorios
G
Giamouzis
Department of Cardiology at University Hospital of Larissa, Larissa, Greece.
Filippos
F
Triposkiadis
Department of Cardiology at University Hospital of Larissa, Larissa, Greece.
Ioannis
I
Skoularigis
D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage*; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004357:Drug Synergism; D004359:Drug Therapy, Combination / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D000069458:Ranolazine / Q000008:administration & dosage*; D026941:Sodium Channel Blockers / Q000008:administration & dosage; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D026941:Sodium Channel Blockers; D000069458:Ranolazine; D000638:Amiodarone
amiodarone; atrial fibrillation; conversion; ranolazine