Reappraising the role of class Ic antiarrhythmics in atrial fibrillation

PURPOSE

The objective of the present systematic review was to compare the effectiveness and safety of class Ic agents for cardioversion of paroxysmal atrial fibrillation (AF), in patients with and without structural heart disease (SHD).

METHODS

We focused on RCTs enrolling at least 50 adult patients with electrocardiogram-documented paroxysmal AF that compared either two pharmacological class Ic cardioversion agents (flecainide, propafenone), regardless of study design (parallel or crossover). We searched MEDLINE and the Cochrane Central Register of Controlled Trials. Initial search was performed from inception to 15 July 2021 with no language restrictions.

RESULTS

Intravenous flecainide is the most effective option for pharmacologic cardioversion of AF since only 2 patients need to be treated in order to cardiovert one more within 4 h. Most importantly, class Ic agents appear to be safe in the context of pharmacologic cardioversion of AF irrespective of the presence of SHD, pointing towards a possible reappraisal of the role in this setting.

CONCLUSION

We suggest that class Ic agents (with flecainide appearing to be more effective) should be used for pharmacologic cardioversion in stable AF patients presenting in emergency department with unknown medical history, after excluding severe cardiac disease through a bedside examination.

REGISTRATION NUMBER (DOI)

Available in https://osf.io/apwt7/ , https://doi.org/10.17605/OSF.IO/APWT7.

Effect of preprocedural pharmacologic cardioversion on pulmonary vein isolation in patients with persistent atrial fibrillation

BACKGROUND

The optimal strategy for catheter ablation of persistent atrial fibrillation (PeAF) remains unknown. A preprocedural additive treatment for patients undergoing pulmonary vein isolation (PVI) alone to optimize catheter ablation should be investigated.

OBJECTIVE

The purpose of this study was to determine whether pharmacologic cardioversion with a fixed low-dose antiarrhythmic drug (AAD) before ablation could stratify the long-term outcome of a PVI-alone strategy.

METHODS

We conducted a prospective cohort study of PeAF patients who underwent PVI using contact force-sensing catheters. No substrate modification was performed. Fixed low-dose bepridil was administered before ablation for cardioversion and patients were classified into 2 groups based on obtaining sinus rhythm (SR). The rate of recurrence of atrial fibrillation (AF) and/or atrial tachycardia (AT) within 36 months was compared between the 2 groups.

RESULTS

Among the 303 PeAF patients who received the AAD, 102 returned to SR (SR group), and the other 201 had persistence of AF (non-SR group). AF persistence duration at baseline and during bepridil administration was similar between the 2 groups. The SR group had a significantly lower 36-month AF/AT recurrence rate than the non-SR group (17 [22.2%] vs 55 [34.0%], log-rank P = .022). AT-type recurrence was observed in 16 patients (2 [3.3%] in the SR group vs 14 [8.9%] in the non-SR group; log-rank P = .051). Nonresponse to AAD was an independent predictor of AF/AT recurrence after adjusting for other risk factors (hazard ratio 1.34; 95% confidence interval 1.01-1.77; P = .040).

CONCLUSION

Preprocedural pharmacologic cardioversion could be a useful determinant for patients with treatable PeAF by PVI alone.

Pharmacologic Cardioversion in Patients with Paroxysmal Atrial Fibrillation: A Network Meta-Analysis

PURPOSE

We sought to indirectly compare and rank antiarrhythmic agents focusing exclusively on adults with paroxysmal atrial fibrillation in order to identify the most effective for pharmacologic cardioversion over different time settings (4 h as primary, and 12, 24 h as secondary outcomes).

METHODS

We searched several databases from inception to March 2020 without language restrictions, ClinicalTrials.gov, references of reviews, and meeting abstract material. We included randomized controlled trials of patients with AF lasting ≤7 days comparing either two or more intravenous (i.v.) or oral (p.o.) pharmacologic cardioversion agents or an agent against placebo. For each outcome, we performed network meta-analysis based on the frequentist approach.

RESULTS

Forty-one trials (6013 patients) were included in our systematic review. Moderate confidence evidence suggests that i.v. vernakalant and flecainide have the highest conversion rate within 4 h, possibly allowing discharge from the emergency department and reducing hospital admissions. Intravenous and p.o. formulations of class IC antiarrhythmics (flecainide more so than propafenone) are superior regarding conversion rates within 12 h, while amiodarone efficacy is exhibited in a delayed fashion (within 24 h), especially if ranolazine is added.

CONCLUSION

Our network meta-analysis identified with sufficient power and consistency the most effective antiarrhythmics for pharmacologic cardioversion over different time settings, with vernakalant and flecainide exhibiting a safer and more efficacious profile toward faster cardioversion.