Intravenous and oral administration of amiodarone for the treatment of recent onset atrial fibrillation after digoxin administration

Safety and Effectiveness of Antidysrhythmic Drugs for Pharmacologic Cardioversion of Recent-Onset Atrial Fibrillation: a Systematic Review and Bayesian Network Meta-analysis

PURPOSE

The available evidence to determine which antidysrhythmic drug is superior for pharmacologic cardioversion of recent-onset (onset within 48 h) atrial fibrillation (AF) is uncertain. We aimed to identify the safest and most effective agent for pharmacologic cardioversion of recent-onset AF in the emergency department.

METHODS

We searched MEDLINE, Embase, and Web of Science from inception to February 21, 2023 (PROSPERO: CRD42018083781). Eligible studies were randomized controlled trials that enrolled adult participants with AF ≤ 48 h, compared a guideline-recommended antidysrhythmic drug with another antidysrhythmic drug or a different formulation of the same drug or placebo and reported specific adverse events. The primary outcome was immediate, serious adverse event - cardiac arrest, sustained ventricular tachydysrhythmia, atrial flutter 1:1 atrioventricular conduction, hypotension, and bradycardia. Additional analyses included the outcomes of conversion to sinus rhythm within 4 h and 24 h. We extracted data according to PRISMA-NMA and appraised trials using Cochrane RoB 2. We performed Bayesian network meta-analysis (NMA) using a Markov Chain Monte Carlo method with random-effect model and vague prior distribution to calculate odds ratios with 95% credible intervals. We assessed confidence using CINeMA. We used surface under the cumulative ranking curve (SUCRA) to rank agent(s).

RESULTS

The systematic review initially identified 5545 studies. Twenty-five studies met eligibility criteria, and 22 studies (n = 3082) provided data for NMA, which demonstrated that vernakalant (SUCRA = 70.9%) is most likely to be safest. Additional effectiveness NMA demonstrated that flecainide (SUCRA = 89.0%) is most likely to be superior for conversion within 4 h (27 studies; n = 2681), and ranolazine-amiodarone IV (SUCRA 93.7%) is most likely to be superior for conversion within 24 h (24 studies; n = 3213). Confidence in the NMA estimates is variable and limited mostly by within-study bias and imprecision.

CONCLUSIONS

Among guideline-recommended antidysrhythmic drugs, the combination of digoxin IV and amiodarone IV is definitely among the least safe for cardioversion of recent onset AF; flecainide, vernakalant, ibutilide, propafenone, and amiodarone IV are definitely among the most effective for cardioversion within 4 h; flecainide is definitely among the most effective for cardioversion within 24 h. Further, randomized controlled trials with predetermined and strictly defined, hemodynamic adverse event outcomes are recommended.

Real-world utilization of the pill-in-the-pocket method for terminating episodes of atrial fibrillation: data from the multinational Antiarrhythmic Interventions for Managing Atrial Fibrillation (AIM-AF) survey

AIMS

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice. Episodes may stop spontaneously (paroxysmal AF); may terminate only via intervention (persistent AF); or may persist indefinitely (permanent AF) (see European and American guidelines, referenced below, for more precise definitions). Recently, there has been renewed interest in an approach to terminate AF acutely referred to as 'pill-in-the-pocket' (PITP). The PITP is recognized in both the US and European guidelines as an effective option using an oral antiarrhythmic drug for acute conversion of acute/recent-onset AF. However, how PITP is currently used has not been systematically evaluated.

METHODS AND RESULTS

The recently published Antiarrhythmic Interventions for Managing Atrial Fibrillation (AIM-AF) survey included questions regarding current PITP usage, stratified by US vs. European countries surveyed, by representative countries within Europe, and by cardiologists vs. electrophysiologists. This manuscript presents the data from this planned sub-study. Our survey revealed that clinicians in both the USA and Europe consider PITP in about a quarter of their patients, mostly for recent-onset AF with minimal or no structural heart disease (guideline appropriate). However, significant deviations exist. See the Graphical abstract for a summary of the data.

CONCLUSION

Our findings highlight the frequent use of PITP and the need for further physician education about appropriate and optimal use of this strategy.

Bayesian Network Meta-analysis of Randomized Controlled Trials on the Efficacy of Antiarrhythmics in the Pharmacological Cardioversion of Paroxysmal Atrial Fibrillation

PURPOSE

Since atrial fibrillation (AF) is one of the major arrhythmias managed in hospitals worldwide, it has a major impact on public health. The guidelines agree on the desirability of cardioverting paroxysmal AF episodes. This meta-analysis aims to answer the question of which antiarrhythmic agent is most effective in cardioverting a paroxysmal AF.

MATERIALS AND METHODS

A systematic review and Bayesian network meta-analysis, searching MEDLINE, Embase, and CINAHL, were performed, including randomized controlled trials (RCTs) enrolling a population of unselected adult patients with a paroxysmal AF that compared at least two pharmacological regimes to restore the sinus rhythm or a cardioversion agent against a placebo. The main outcome was efficacy in restoring sinus rhythm.

RESULTS

Sixty-one RCTs (7988 patients) were included in the quantitative analysis [deviance information criterion (DIC) 272.57; I² = 3%]. Compared with the placebo, the association verapamil-quinidine shows the highest SUCRA rank score (87%), followed by antazoline (86%), vernakalant (85%), tedisamil at high dose (i.e., 0.6 mg/kg; 80%), amiodarone-ranolazine (80%), lidocaine (78%), dofetilide (77%), and intravenous flecainide (71%). Taking into account the degree of evidence of each individual comparison between pharmacological agents, we have drawn up a ranking of pharmacological agents from the most effective to the least effective.

CONCLUSIONS

In comparing the antiarrhythmic agents used to restore sinus rhythm in the case of paroxysmal AF, vernakalant, amiodarone-ranolazine, flecainide, and ibutilide are the most effective medications. The verapamil-quinidine combination seems promising, though few RCTs have studied it. The incidence of side effects must be taken into account in the choice of antiarrhythmic in clinical practice.

CLINICAL TRIAL REGISTRATION

PROSPERO: International prospective register of systematic reviews, 2022, CRD42022369433 (Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022369433 ).

Pharmacokinetic Disposition of Amiodarone When Given with an Intralipid Rescue Strategy

While the antiarrhythmic drug amiodarone is commonly used in clinical practice, it has a narrow therapeutic index that can lead to acute overdose. One proposed method to deal with this toxicity is lipid emulsion therapy, which may potentially quench the free amiodarone in blood and prevent its further distribution to target organs and tissues. In this study, we utilize an established swine model to examine the effects of Intralipid™ (IL) administration for acute amiodarone toxicity. A total of 14 pigs received an overdose of intravenous amiodarone. After twenty minutes, half of the pigs (n = 7) received IL while the control group (n = 7) received normal saline. Serum concentrations of amiodarone were then analyzed using a validated high-performance liquid chromatography (HPLC) method. Noncompartmental pharmacokinetic analyses were performed on the observed concentrations. There were no statistical differences in the area under the concentration time curve (6 h) or clearance, but there was a difference in the half-life between the two groups (3.12 vs. 0.85 h, p = 0.01). The administration of IL did not statistically change the overall exposure of amiodarone in the blood in the first 6 h; however, trends toward prolonged blood retention in the IL group were seen.

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.

Phlebitis in Intravenous Amiodarone Administration: Incidence and Contributing Factors

BACKGROUND

Intravenous amiodarone is the gold-standard treatment for arrhythmias, but phlebitis is a common adverse effect.

OBJECTIVES

To determine the incidence and contributing factors of amiodarone-induced phlebitis and examine phlebitis severity.

METHODS

A systematic review was conducted of articles published before February 2016 in the Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, MEDLINE, Embase, Web of Science, and gray databases (Bielefeld, Lenus, EUGrey, RIAN, and DART). All studies in which amiodarone-induced phlebitis was a primary or secondary outcome were included. Meta-analysis was not appropriate because of study heterogeneity. Studies of the same contributing factors were analyzed together.

RESULTS

In the 20 included studies, phlebitis incidence ranged from 0% to 85%. Increasing the infusion concentration from 1.2 mg/mL to 1.8 mg/mL increased the phlebitis rate (P < .001). Total amiodarone doses greater than 1 g resulted in higher phlebitis rates than did doses less than 0.45 mg (P < .001). Most infusion durations and rates were not correlated with phlebitis incidence. However, phlebitis incidence was lower with bolus administration than with longer infusions (P = .002). The use of in-line filters and nursing guidelines significantly reduced phlebitis rates (P < .001) and phlebitis severity. The most common phlebitis severity grades, in descending order, were 0, 1, 2, 3, and 4.

CONCLUSIONS

Understanding factors that increase the risk of amiodarone-induced phlebitis can guide better practice. In-line filters and nursing guidelines should always be implemented when administering intravenous amiodarone. Increased surveillance is required when higher dosages and concentrations are used.

Comedication with interacting drugs predisposes amiodarone users in cardiac and surgical intensive care units to acute liver injury: A retrospective analysis

Risk factors and underlying mechanisms for liver injury associated with amiodarone remain elusive. This study aimed to investigate the drug-related covariates for acute liver injury by amiodarone-an intriguing compound of high lipophilicity, with a long half-life and notable efficacy.The medical, pharmacy, and laboratory records of new amiodarone users admitted to the cardiac or surgical intensive care units of a medical center were examined retrospectively. A Cox regression model with time-varying dose-related variables of amiodarone was utilized to estimate the hazard ratio (HR) of amiodarone-associated liver injury while adjusting for concomitant therapy and relevant covariates.Of the 131 eligible patients among 6,572 amiodarone users (46,402 prescriptions), 6 were identified as amiodarone-associated liver injury cases. In comparison to controls (n = 125), this liver injury cohort (n = 6) had significantly higher numbers of amiodarone-interacting (2.7 ± 2.0 vs 0.9 ± 0.9 drugs, P = .02) and hepatotoxic (3.8 ± 0.8 vs 2.5 ± 1.7 drugs, P = .03) comedications. The number of comedications with amiodarone-interacting potential (HR 2.07, 95% confidence interval [CI] 1.02-4.22, P = .04) and amiodarone cumulative doses standardized by body surface area (HR 6.82, 95% CI 1.72-27.04, P = .01) were independent risk factors for liver injury associated with amiodarone.Drug-related (amiodarone cumulative dose, interacting drugs) factors were significant predictors of amiodarone-associated acute liver injury. A prudent evaluation of each medication profile is warranted to attain precision medicine at the level of patient care, especially for those treated by medications with complex physicochemical and pharmacokinetic properties, such as amiodarone.

Intralipid™ administration attenuates the hypotensive effects of acute intravenous amiodarone overdose in a swine model

PURPOSE

To investigate whether a lipid emulsion could counteract the hypotensive effects of amiodarone overdose after an acute intravenous administration and improve 4 h survival in an established model of swine cardiovascular research.

METHODS

Twenty pigs were intubated and instrumented to measure aortic pressures and central venous pressures (CVP). After allowing the animals to stabilize for 60 minutes, amiodarone overdose (1 mg/kg/min) was initiated for a maximum of 20 minutes. Afterwards, the animals were randomized into 2 groups. Group A (n = 10) received 0.9% Normal Saline (NS) and Group B (n = 10) received 20% Intralipid® (ILE). A bolus dose of 2 ml/kg in over 2 min time was initially administered in both groups followed by a 45 min infusion (0.2 ml/kg/min) of either NS or ILE.

RESULTS

All animals survived the overdose and all animals survived the monitoring period of 4 hours. Systolic aortic pressure (SpthAorta) (6.90 vs 14.10 mmHg, P = .006) and mean arterial pressure (MAP) (6.10 vs 14.90 mmHg, P = .001) were higher in the ILE group 2 min after the bolus ILE infusion. This difference was maintained for 15 min after ILE infusion for both SpthAorta (7.85 vs 13.15 mmHg, P = .044) and MAP (7.85 vs 13.15 mmHg, P = .042). Animals that received ILE had higher CVP (11.6 vs 15.7 mmHg, P = .046), an effect which was attenuated 2 and 4 hours post administration. Animals receiving ILE were more acidotic (7.21 vs 7.38, P = .048) in the monitoring period compared to animals receiving NS.

CONCLUSIONS

Intralipid attenuated the hypotensive effects of amiodarone toxicity for a period of 15 minutes compared to animals receiving NS.

Antiarrhythmic drugs for atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is associated with increased mortality and morbidity. Although stroke prevention is the only way to improve prognosis, antiarrhythmic drugs (AADs) are of primary importance both in the conversion to sinus rhythm and in the long-term control of rhythm and rate.

AREAS COVERED

We searched the Cochrane Library and Medline Database for articles published in English concerning efficacy and safety of AADs in AF. Particular attention was paid to the recently published European Society of Cardiology guidelines. This review provides an overview of the currently available drugs used in AF, with a particular emphasis on their comparative efficacy and safety in different kind of patients. Recent important findings, and advantages and disadvantages of recently approved drugs such as vernakalant and dronedarone, are also discussed.

EXPERT OPINION

AADs remain fundamental in the acute and long-term management of AF, to control symptoms and to reduce the negative impact of the arrhythmia on QoL. The choice of a rate- over rhythm-control strategy should be individualized and based on accurate evaluation of patient medical history and symptoms. New agents will contribute to improve treatment efficacy together with the guarantee of better safety profiles.

Pharmacologic Conversion of Atrial Fibrillation and Atrial Flutter

Atrial fibrillation and atrial flutter are common arrhythmias in everyday clinical settings. Pharmacologic cardioversion (CV) is a simple and widely used strategy for the treatment of these arrhythmias, and many drugs are currently available. The choice of drug is strongly influenced by the time elapsed from atrial fibrillation onset and by a patient's clinical subset. Electrical direct-current CV is the treatment of choice in long-lasting forms; nevertheless, some agents also show efficacy in this setting. In addition, promising results come from studies on the efficacy and safety of new antiarrhythmic drugs and from therapeutic approaches that reduce the need for hospitalization and improve quality of life.

A formula for the stratified selection of patients with paroxysmal atrial fibrillation in the emergency setting: a retrospective pilot study

BACKGROUND

Amiodarone is a commonly used medication in the treatment of atrial fibrillation (AF) of recent onset.

STUDY OBJECTIVES

The aim of the study was to identify a possible formula for selecting Emergency Department (ED) patients with paroxysmal AF who will spontaneously restore sinus rhythm (SR), successfully restore SR with the use of loading intravenous (i.v.) amiodarone, or require 24-h maintenance amiodarone infusion.

METHODS

This retrospective pilot study included 141 patients with recent-onset AF. Patients who did not restore SR spontaneously received i.v. amiodarone (5 mg/kg) within a period of 30 min. In case of no response, an additional dosage of 1000 mg of i.v. amiodarone was administered over a period of 24 h. Binary logistic regression models were used to determine the predictors of spontaneous conversion and the response to amiodarone administration.

RESULTS

The formula ([heart rate/systolic blood pressure] + 0.1 × number of past AF incidences) was chosen as the one with the highest combined sensitivity and specificity. This index identified the patients who spontaneously restored SR (cutoff point 1.31 with 78.6% sensitivity and 77.9% specificity), whereas for patients who responded to the loading i.v. amiodarone dose, the use of the index (cutoff point 1.24) exhibited 84.1% sensitivity and 75.3% specificity.

CONCLUSIONS

This formula may be a useful and reliable bedside diagnostic tool to identify AF patients most likely to spontaneously convert, or respond to loading amiodarone administration in the emergency setting. The use of this index also can assist in patient risk stratification.