BACKGROUND: Vernakalant is an available drug for the treatment of recent-onset atrial fibrillation, producing conversion between 55% and 87% of the patients treated. In this sense, little is known about the predictors of conversion with this agent. The aim of our study was to analyze the predictors of conversion in our 2-year experience using vernakalant for the treatment of recent-onset atrial fibrillation.

METHODS: One hundred twenty-one patients with recent-onset atrial fibrillation without hemodynamic impairment received pharmacological treatment with vernakalant. Clinical variables, history of cardiovascular diseases, and echocardiographic data were recorded.

RESULTS: Mean age was 58.1 ± 13.9 years and 13.4% of patients had structural heart disease. Conversion to sinus rhythm was achieved in 84.5% of patients, and 46% required the second dose of vernakalant. After analyzing the predictors of conversion, the presence of structural heart disease was significantly larger in the group without conversion (35.3 vs 9.7%; P = 0.02). The mean ejection fraction in the group with conversion was 61.05 ± 5.7% versus 54.9 ± 8.4% in the group without conversion (P = 0.016). After dichotomizing the variable ejection fraction, patients with ejection fraction <55% had a lower conversion rate (P = 0.001).

CONCLUSION: In our study, the absence of any kind of structural heart disease and preserved systolic function were associated with greater conversion rate with vernakalant.

לקריאת המאמר:

Costabel JP¹, Lambardi F, Aragón M, Campos R, Urdapilleta M, Ariznavarreta P, Vergara JM, Conde D. Predictors of conversion of recent-onset atrial fibrillation treated with vernakalant. Pacing Clin Electrophysiol. 2015 Feb;38(2):196-200.

INTRODUCTION:

An oral loading dose of propafenone 600 mg is used in our center as in other places around the world for conversion of recent-onset atrial fibrillation (AF) in patients without structural heart disease. Vernakalant is a novel, safe, and effective drug used intravenously and has proved to be more rapid in converting recent-onset AF to sinus rhythm compared with placebo and amiodarone. There is no study that comparesvernakalant with propafenone. The aim of our study is to compare the time taken for conversion of recent-onset AF in patients treated withvernakalant and propafenone.

METHODS:

Thirty-six hemodynamically stable patients with recent-onset AF without structural heart disease were prospectively included. A single oral dose of propafenone 600 mg was administered to 19 patients and 17 received intravenous vernakalant. Clinical and laboratory variables, conversion rate, and time to conversion were recorded.

RESULTS:

Baseline characteristics were similar in both groups. Time to conversion to sinus rhythm was of 166 min (120-300) in the propafenonegroup versus 9 min (6-18) in the vernakalant group (P = 0.0001). Conversion rate was of 78% in the propafenone group at 8 h and of 93% in thevernakalant group at 2 h; yet, this difference was not statistically significant (P = 0.4). Time to conversion had a direct impact in hospital stay, which was 43% shorter in the vernakalant group (P = 0.0001).

CONCLUSION:

Time to conversion of AF to sinus rhythm was significantly shorter in the vernakalant group compared with the propafenone group and was associated with shorter hospital stay.

לקריאת המאמר:

Conde D, Costabel JP, Aragon M, Lambardi F, Klein A, Corrales Barbosa A, Trivi M, Giniger A. Propafenone versus vernakalant for conversion of recent-onset atrial fibrillation.Cardiovasc Ther. 2013 Dec;31(6):377-80.

Primary efficacy endpoint was the proportion of subjects with short duration atrial fibrillation (3 hours to 7 days) who had a treatment-induced conversion of atrial fibrillation to sinus rhythm for a minimum duration of one minute within 90 minutes of first exposure to study drug. Efficacy was studied in a total of 390 haemodynamically stable adult patients with short duration atrial fibrillation including patients with hypertension (40.5%), ischaemic heart disease (12.8%), valvular heart disease (9.2%) and CHF (10.8%). In these studies treatment with BRINAVESS effectively converted atrial fibrillation to sinus rhythm as compared with placebo (see Table x). Conversion of atrial fibrillation to sinus rhythm occurred rapidly (in responders the median time to conversion was 10 minutes from start of first infusion) and sinus rhythm was maintained through 24 hours (97%). The vernakalant dose recommendation is a titrated therapy with two possible dose steps. In the performed clinical studies, the additive effect of the second dose, if any, cannot be independently established.

BRINAVESS was shown to provide relief of atrial fibrillation symptoms consistent with conversion to sinus rhythm.

No significant differences in safety or effectiveness were observed based on age, gender, use of rate control medications, use of antiarrhythmic medications, use of warfarin, history of ischaemic heart disease, renal impairment or expression of the cytochrome P450 2D6 enzyme.

Treatment with BRINAVESS did not affect the response rate to electrical cardioversion (including the median number of shocks or joules required for successful cardioversion) in cases when attempted within 2 to 24 hours of study medicine administration.

Conversion of atrial fibrillation in patients with longer-duration atrial fibrillation (> 7 days and ≤ 45 days) assessed as a secondary efficacy endpoint in a total of 185 patients did not show statistically significant differences between BRINAVESS and placebo.

References:

1. עלון לרופא עמודים 8-9