What is the clinical evidence from this study?

Study design: RCT. Population: paroxysmal atrial fibrillation (n=666). Intervention: verapamil vs. beta blockers or no rate control. Primary outcome: composite of first electrical cardioversion (ECV), chemical cardioversion (CCV), or atrial ablation (HR 0.40, 95% CI 0.19-0.83, p=0.038).

July 14, 2021Open Access

Rate control drugs differ in the prevention of progression of atrial fibrillation

Key Result

Verapamil was associated with significantly less AF progression compared to beta blockers (HR 0.40; 95% CI 0.19-0.83) and no rate control (HR 0.64; 95% CI 0.44-0.93) in patients with paroxysmal AF.

Study Design

Type

RCT (n=666)

Structured PICO

Does verapamil reduce the composite of first electrical cardioversion, chemical cardioversion, or atrial ablation in patients with newly diagnosed paroxysmal atrial fibrillation compared to beta blockers or no rate control?

Population

666 patients with newly diagnosed paroxysmal atrial fibrillation (AF). Excluded: patients using Vaughan-Williams Class I or III antiarrhythmic drugs.

Intervention

Verapamil

Comparator

Beta blockers or no rate control

Outcome

Composite of first electrical cardioversion (ECV), chemical cardioversion (CCV), or atrial ablationcomposite

In patients with newly diagnosed paroxysmal AF, verapamil may be associated with less AF progression (defined by need for cardioversion or ablation) compared to beta blockers or no rate control.

Main Result

Effect estimate: HR 0.40 (95% CI 0.19-0.83)

Absolute Event Rate: 17% vs 33%

p-value: p=0.038

Abstract

AIMS: We hypothesize that in patients with paroxysmal atrial fibrillation (AF), verapamil is associated with lower AF progression compared to beta blockers or no rate control. METHODS AND RESULTS: In this pre-specified post hoc analysis of the RACE 4 randomized trial, the effect of rate control medication on AF progression in paroxysmal AF was analysed. Patients using Vaughan-Williams Class I or III antiarrhythmic drugs were excluded. The primary outcome was a composite of first electrical cardioversion (ECV), chemical cardioversion (CCV), or atrial ablation. Event rates are displayed using Kaplan-Meier curves and multivariable Cox regression analyses are used to adjust for baseline differences. Out of 666 patients with paroxysmal AF, 47 used verapamil, 383 used beta blockers, and 236 did not use rate control drugs. The verapamil group was significantly younger than the beta blocker group and contained more men than the no rate control group. Over a mean follow-up of 37 months, the primary outcome occurred in 17% in the verapamil group, 33% in the beta blocker group, and 33% in the no rate control group (P = 0.038). After adjusting for baseline characteristics, patients using verapamil have a significantly lower chance of receiving ECV, CCV, or atrial ablation compared to patients using beta blockers hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.19-0.83 and no rate control (HR 0.64, 95% CI 0.44-0.93). CONCLUSION: In patients with newly diagnosed paroxysmal AF, verapamil was associated with less AF progression, as compared to beta blockers and no rate control.