Impact of chronic obstructive pulmonary disease in patients with atrial fibrillation: an analysis from the GLORIA-AF registry

AIMS

Chronic obstructive pulmonary disease (COPD) may influence management and prognosis of atrial fibrillation (AF), but this relationship has been scarcely explored in contemporary global cohorts. We aimed to investigate the association between AF and COPD, in relation to treatment patterns and major outcomes.

METHODS AND RESULTS

From the prospective, global GLORIA-AF registry, we analysed factors associated with COPD diagnosis, as well as treatment patterns and risk of major outcomes in relation to COPD. The primary outcome was the composite of all-cause death and major adverse cardiovascular events (MACEs). A total of 36 263 patients (mean age 70.1 ± 10.5 years, 45.2% females) were included; 2,261 (6.2%) had COPD. The prevalence of COPD was lower in Asia and higher in North America. Age, female sex, smoking, body mass index, and cardiovascular comorbidities were associated with the presence of COPD. Chronic obstructive pulmonary disease was associated with higher use of oral anticoagulant (OAC) [adjusted odds ratio (aOR) and 95% confidence interval (CI): 1.29 (1.13-1.47)] and higher OAC discontinuation [adjusted hazard ratio (aHR) and 95% CI: 1.12 (1.01-1.25)]. Chronic obstructive pulmonary disease was associated with less use of beta-blocker [aOR (95% CI): 0.79 (0.72-0.87)], amiodarone and propafenone, and higher use of digoxin and verapamil/diltiazem. Patients with COPD had a higher hazard of primary composite outcome [aHR (95% CI): 1.78 (1.58-2.00)]; no interaction was observed regarding beta-blocker use. Chronic obstructive pulmonary disease was also associated with all-cause death [aHR (95% CI): 2.01 (1.77-2.28)], MACEs [aHR (95% CI): 1.41 (1.18-1.68)], and major bleeding [aHR (95% CI): 1.48 (1.16-1.88)].

CONCLUSION

In AF patients, COPD was associated with differences in OAC treatment and use of other drugs; Patients with AF and COPD had worse outcomes, including higher mortality, MACE, and major bleeding.

Propafenone versus amiodarone for supraventricular arrhythmias in septic shock: a randomised controlled trial

PURPOSE

Acute onset supraventricular arrhythmias can contribute to haemodynamic compromise in septic shock. Both amiodarone and propafenone are available interventions, but their clinical effects have not yet been directly compared.

METHODS

In this two-centre, prospective controlled parallel group double blind trial we recruited 209 septic shock patients with new-onset arrhythmia and a left ventricular ejection fraction above 35%. The patients were randomised in a 1:1 ratio to receive either intravenous propafenone (70 mg bolus followed by 400-840 mg/24 h) or amiodarone (300 mg bolus followed by 600-1800 mg/24 h). The primary outcomes were the proportion of patients who had sinus rhythm 24 h after the start of the infusion, time to restoration of the first sinus rhythm and the proportion of patients with arrhythmia recurrence.

RESULTS

Out of 209 randomized patients, 200 (96%) received the study drug. After 24 h, 77 (72.8%) and 71 (67.3%) were in sinus rhythm (p = 0.4), restored after a median of 3.7 h (95% CI 2.3-6.8) and 7.3 h (95% CI 5-11), p = 0.02, with propafenone and amiodarone, respectively. The arrhythmia recurred in 54 (52%) patients treated with propafenone and in 80 (76%) with amiodarone, p  < 0.001. Patients with a dilated left atrium had better rhythm control with amiodarone (6.4 h (95% CI 3.5; 14.1) until cardioversion vs 18 h (95% CI 2.8; 24.7) in propafenone, p = 0.05).

CONCLUSION

Propafenone does not provide better rhythm control at 24 h yet offers faster cardioversion with fewer arrhythmia recurrences than with amiodarone, especially in patients with a non-dilated left atrium. No differences between propafenone and amiodarone on the prespecified short- and long-term outcomes were observed.

Amiodarone but not propafenone impairs bioenergetics and autophagy of human myocardial cells

Cardiac and extra-cardiac side effects of common antiarrhythmic agents might be related to drug-induced mitochondrial dysfunction. Supratherapeutic doses of amiodarone have been shown to impair mitochondria in animal studies, whilst influence of propafenone on cellular bioenergetics is unknown. We aimed to assess effects of protracted exposure to pharmacologically relevant doses of amiodarone and propafenone on cellular bioenergetics and mitochondrial biology of human and mouse cardiomyocytes. In this study, HL-1 mouse atrial cardiomyocytes and primary human cardiomyocytes derived from the ventricles of the adult heart were exposed to 2 and 7 μg/mL of either amiodarone or propafenone. After 24 h, extracellular flux analysis and confocal laser scanning microscopy were used to measure mitochondrial functions. Autophagy was assessed by western blots and live-cell imaging of lysosomes. In human cardiomyocytes, amiodarone significantly reduced mitochondrial membrane potential and ATP production, in association with an inhibition of fatty acid oxidation and impaired complex I- and II-linked respiration in the electron transport chain. Expectedly, this led to increased anaerobic glycolysis. Amiodarone increased the production of reactive oxygen species and autophagy was also markedly affected. In contrast, propafenone-exposed cardiomyocytes did not exert any impairment of cellular bioenergetics. Similar changes after amiodarone treatment were observed during identical experiments performed on HL-1 mouse cardiomyocytes, suggesting a comparable pharmacodynamics of amiodarone among mammalian species. In conclusion, amiodarone but not propafenone in near-therapeutic concentrations causes a pattern of mitochondrial dysfunction with affected autophagy and metabolic switch from oxidative metabolism to anaerobic glycolysis in human cardiomyocytes.

Chronic Propafenone Application Increases Functional KIR2.1 Expression In Vitro

Expression and activity of inwardly rectifying potassium (K_IR) channels within the heart are strictly regulated. K_IR channels have an important role in shaping cardiac action potentials, having a limited conductance at depolarized potentials but contributing to the final stage of repolarization and resting membrane stability. Impaired K_IR2.1 function causes Andersen-Tawil Syndrome (ATS) and is associated with heart failure. Restoring K_IR2.1 function by agonists of K_IR2.1 (AgoKirs) would be beneficial. The class 1c antiarrhythmic drug propafenone is identified as an AgoKir; however, its long-term effects on K_IR2.1 protein expression, subcellular localization, and function are unknown. Propafenone's long-term effect on K_IR2.1 expression and its underlying mechanisms in vitro were investigated. K_IR2.1-carried currents were measured by single-cell patch-clamp electrophysiology. K_IR2.1 protein expression levels were determined by Western blot analysis, whereas conventional immunofluorescence and advanced live-imaging microscopy were used to assess the subcellular localization of K_IR2.1 proteins. Acute propafenone treatment at low concentrations supports the ability of propafenone to function as an AgoKir without disturbing K_IR2.1 protein handling. Chronic propafenone treatment (at 25-100 times higher concentrations than in the acute treatment) increases K_IR2.1 protein expression and K_IR2.1 current densities in vitro, which are potentially associated with pre-lysosomal trafficking inhibition.

Metabolic Activation and Cytotoxicity of Propafenone Mediated by CYP2D6

Propafenone (PPF) is a class I_C antidysrhythmic drug, which is commonly used for the treatment of atrial fibrillation and other supraventricular arrhythmias. It is also a β-adrenoceptor antagonist that can cause bradycardia and bronchospasm. Hepatotoxicity is one of the adverse reactions reported, with clinical manifestations including acute cholestasis and hepatocyte necrosis. However, the mechanism of PPF-induced hepatotoxicity remains unclear. The present study was conducted to identify reactive metabolite(s) to determine related metabolic pathways and define the possible association of the bioactivation with PPF cytotoxicity. An O-demethylation phase I metabolite (M1), a further position C5 hydroxylation (para-position of the benzene ring) metabolite (M2), glutathione (GSH) conjugates (M3 and M4), and N-acetylcysteine (NAC) conjugates (M5 and M6) were detected in rat liver microsomal incubations containing PPF and GSH or NAC as trapping agents. The corresponding GSH conjugates and NAC conjugates were found in the bile and urine of rats after PPF administration, respectively. The observed GSH and NAC conjugates indicate that a quinone metabolite was generated in vitro and in vivo. Recombinant P450 enzyme incubations showed that CYP2D6 was the principal enzyme catalyzing this metabolic activation. Quinidine, a selective inhibitor of CYP2D6, attenuated the susceptibility of hepatocytes to the cytotoxicity of PPF. The results suggest that PPF was metabolized to a p-quinone intermediate which may be involved in PPF-induced hepatotoxicity.

Modern treatment of supraventricular tachycardia

Supraventricular tachycardia (SVT) is one of the most common arrhythmias. The prevalence of SVT varies widely in different countries and is 2,25 per 1,000 people in the general population. SVT reduce the quality of life of patients, and in some cases can worsen the prognosis. In patients with cardiovascular disease, the risk of SVT increases. Therapy of SVT is selected depending on the stability of hemodynamic and the QRS width. Until now, the treatment of SVT remains an urgent issue of modern cardiology, since despite the high effectiveness of catheter ablation, antiarrhythmic therapy plays an important role.

Comparison of Amiodarone and Propafenone in Blanking Period after Radiofrequency Catheter Ablation in Patients with Atrial Fibrillation: A Propensity Score-Matched Study

Background

Amiodarone and propafenone are commonly used to maintain sinus rhythm in patients with atrial fibrillation (AF). However, it is not known which one is better in reducing early recurrence (ER) during the blanking period (the first three months after catheter ablation).

Objective

To compare the efficacy and safety of amiodarone and propafenone in reducing ER during the blanking period after radiofrequency catheter ablation (RFCA) in AF patients.

Materials and Methods

A total of 694 patients who underwent their first RFCA between May 2014 and May 2018 were enrolled in this retrospective study. Subsequently, 202 patients were excluded according to the exclusion criteria. The remaining 492 patients were divided into two groups based on the choice of antiarrhythmic drugs (AADs) (amiodarone or propafenone) in the blanking period. The primary outcomes were incidence of ER and AAD-associated adverse effects during the blanking period after RFCA. Propensity score matching (PSM) analyses were used to compare the outcomes of the two groups while controlling for confounders.

Results

Among the 492 patients who took AADs in the blanking period (187 amiodarone and 305 propafenone), PSM selected 135 unique pairs of patients with similar characteristics. Amiodarone was associated with a lower ER incidence rate (23.7% versus 48.9%, p < 0.001) and a similar rate of AAD-associated adverse effects (2.1% versus 1.5%, p = 0.652). Treatment with amiodarone in the blanking period was significantly associated with a lower ER incidence rate compared to treatment with propafenone (HR = 0.416, 95% CI 0.272–0.637, p < 0.001).

Conclusions

Compared with propafenone, amiodarone was associated with a lower ER incidence rate, and they had similar rates of AAD-associated adverse effects. Treatment with amiodarone in the blanking period was shown to be more effective in reducing ER than propafenone.

Efficacy and safety of 1C class antiarrhythmic agent (propafenone) for supraventricular arrhythmias in septic shock compared to amiodarone: protocol of a prospective randomised double-blind study

INTRODUCTION

Supraventricular arrhythmias contribute to haemodynamic compromise in septic shock. A retrospective study generated the hypothesis that propafenone could be more effective than amiodarone in achieving and maintaining sinus rhythm (SR). Certain echocardiographic parameters may predict a successful cardioversion and help in the decision on rhythm or rate control strategy.

METHODS AND ANALYSIS

The trial includes septic shock patients with new-onset arrhythmia, but without severe impairment of the left ventricular ejection fraction. After baseline echocardiography, the patient is randomised to receive a bolus and maintenance dose of either amiodarone or propafenone. The primary outcome is the proportion of patients that have achieved rhythm control at 24 hours after the start of the infusion. The secondary outcomes are the percentages of patients that needed rescue treatments (DC cardioversion or unblinding and crossover of the antiarrhythmics), the recurrence of arrhythmias, intensive care unit mortality, 28-day and 1-year mortality. In the posthoc analysis, we separately assess subgroups of patients with pulmonary hypertension and right ventricular dysfunction. In the exploratory part of the study, we assess whether the presence of a transmitral diastolic A wave and its higher velocity-time integral is predictive for the sustainability of mechanical SR and whether the indexed left atrial endsystolic volume is predictive of recurrent arrhythmia. Considering that the restoration of SR within 24 hours occurred in 74% of the amiodarone-treated patients and in 89% of the patients treated with propafenone, we plan to include 200 patients to have an 80% chance to demonstrate the superiority of propafenone at p=0.05.

ETHICS AND DISSEMINATION

The trial is recruiting patients according to its second protocol version approved by the University Hospital Ethical Board on the 6 October 2017 (No. 1691/16S-IV). The results will be disseminated through peer reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT03029169.

Antiarrhythmic therapy in the treatment of atrial fibrillation: yesterday, today, tomorrow

Atrial fibrillation (AF) is the most common heart rhythm disorder encountered in clinical practice. Each year, the number of patients with AF significantly increases. It is associated with an increase of life expectancy and frequency of cardiovascular pathologies. Treatment of AF remains one of the most difficult tasks of modern cardiology. Currently, only a few antiarrhythmic drugs are available for use in Russia. More and more new attempts are being made to create a universal antiarrhythmic drug with a high level of anti-relapsing efficacy and adverse effects. The accumulated information suggests that the tactics of management of patients with arrhythmias will be intended to improving the new surgical and interventional treatment methods with use of anticoagulants and antiarrhythmic drugs. The multidisciplinary team of specialists on AF treatment should include an expert (cardiologist) in antiarrhythmic drug therapy, an interventional electrophysiologist, and a cardiac surgeon — master the technology of interventional or surgical ablation. Effective interaction of specialists of various levels will improve the results of rhythm control and prevention of complications in patients with AF.

Atria-selective antiarrhythmic drugs in need of alliance partners

Atria-selective antiarrhythmic drugs in need of alliance partners. Guideline-based treatment of atrial fibrillation (AF) comprises prevention of thromboembolism and stroke, as well as antiarrhythmic therapy by drugs, electrical rhythm conversion, ablation and surgical procedures. Conventional antiarrhythmic drugs are burdened with unwanted side effects including a propensity of triggering life-threatening ventricular fibrillation. In order to solve this therapeutic dilemma, 'atria-selective' antiarrhythmic drugs have been developed for the treatment of supraventricular arrhythmias. These drugs are designed to aim at atrial targets, taking advantage of differences in atrial and ventricular ion channel expression and function. However it is not clear, whether such drugs are sufficiently antiarrhythmic or whether they are in need of an alliance partner for clinical efficacy. Atria-selective Na⁺ channel blockers display fast dissociation kinetics and high binding affinity to inactivated channels. Compounds targeting atria-selective K⁺ channels include blockers of ultra rapid delayed rectifier (Kv1.5) or acetylcholine-activated inward rectifier K⁺ channels (Kir3.x), inward rectifying K⁺ channels (Kir2.x), Ca²⁺-activated K⁺ channels of small conductance (SK), weakly rectifying two-pore domain K⁺ channels (K_2P), and transient receptor potential channels (TRP). Despite good antiarrhythmic data from in-vitro and animal model experiments, clinical efficacy of atria-selective antiarrhythmic drugs remains to be demonstrated. In the present review we will briefly summarize the novel compounds and their proposed antiarrhythmic action. In addition, we will discuss the evidence for putative improvement of antiarrhythmic efficacy and potency by addressing multiple pathophysiologically relevant targets as possible alliance partners.

Anti-arrhythmic therapy in athletes

The spectrum of arrhythmias that may be encountered in athletes ranges from isolated ectopic beats to ventricular tachycardia, usually in the context of a structurally normal heart. Anti-arrhythmic therapy in these individuals may be particularly challenging because of the young age, the hypervagotonic state, the desire to maintain a high physical performance, the reluctance to take medications and the need to avoid molecules included in the list of prohibited drugs of the World Anti-Doping Agency. Furthermore, the possible serious adverse effects of anti-arrhythmic drugs should be balanced against the benign nature of arrhythmias in patients with no underlying heart disease. The review summarizes the most common arrhythmias of athletes and the possible therapeutic options, including anti-arrhythmic drugs and non-pharmacological interventions. Eligibility criteria according to current guidelines are also addressed.

Comparison of the effects of IK,ACh, IKr, and INa block in conscious dogs with atrial fibrillation and on action potentials in remodeled atrial trabeculae

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a major cause of morbidity and mortality. Traditional antiarrhythmic agents used for restoration of sinus rhythm have limited efficacy in long-term AF and they may possess ventricular proarrhythmic adverse effects, especially in patients with structural heart disease. The acetylcholine receptor-activated potassium channel (I_K,ACh) represents an atrial selective target for future AF management. We investigated the effects of the I_K,ACh blocker tertiapin-Q (TQ), a derivative of the honeybee toxin tertiapin, on chronic atrial tachypacing-induced AF in conscious dogs, without the influence of anesthetics that modulate a number of cardiac ion channels. Action potentials (APs) were recorded from right atrial trabeculae isolated from dogs with AF. TQ significantly and dose-dependently reduced AF incidence and AF episode duration, prolonged atrial effective refractory period, and prolonged AP duration. The reference drugs propafenone and dofetilide, both used in the clinical management of AF, exerted similar effects against AF in vivo. Dofetilide prolonged atrial AP duration, whereas propafenone increased atrial conduction time. TQ and propafenone did not affect the QT interval, whereas dofetilide prolonged the QT interval. Our results show that inhibition of I_K,ACh may represent a novel, atrial-specific target for the management of AF in chronic AF.

Efficacy and safety in pharmacological cardioversion of recent-onset atrial fibrillation: a propensity score matching to compare amiodarone vs class IC antiarrhythmic drugs

The acute management of recent-onset (<48 h) atrial fibrillation (AF) is still debated. Aim of our study was to compare efficacy and safety of intravenously administered class IC antidysrhythmic agents vs amiodarone in a propensity score matched series of patients acutely treated for AF in the emergency department. During a 3-year period, we retrospectively evaluated all episodes of recent-onset (<48 h) AF pharmacologically treated for sinus rhythm restoration in the emergency department. By means of a propensity score matching considering the main statistically different covariates, we selected two accurately matched treatment groups. We analysed the differences between amiodarone and class IC group in terms of efficacy and safety that is conversion to sinus rhythm rates within 12 and 48 h after starting treatment, time to conversion, and adverse drug effects. An overall number of 817 episodes of recent-onset AF were collected (amiodarone group = 406, class IC group = 411). After matching, we obtained 358 episodes equally divided (amiodarone group = 179 and class IC group = 179). Conversion rates within 12 h were 139 (53.1 %) in amiodarone group and 95 (72.6 %) in class IC group (p < 0.05). Median time for cardioversion was 420 min (331.6-508.3 CI 95 %) in amiodarone and 55 min (44.9-65.1 CI 95 %) in class IC group (p < 0.05). The incidence of adverse events in both groups was very low and equally distributed (p = ns). Intravenously administration of class IC agents, when compared with amiodarone, proved to be more rapid and effective, and equally safe in the acute management of recent-onset AF.

Assessment of 25 CYP2D6 alleles found in the Chinese population on propafenone metabolism in vitro

Cytochrome P450 enzyme 2D6 (CYP2D6) is an important member of the cytochrome P450 enzyme superfamily, with more than 100 CYP2D6 allelic variants being previously reported. The aim of this study was to assess the catalytic characteristics of 25 alleles (CYP2D6.1 and 24 CYP2D6 variants) and their effects on the metabolism of propafenone in vitro. Twenty-five CYP2D6 alleles were expressing in 21 Spodoptera frugiperda (Sf) insect cells, and each variant was evaluated using propafenone as the substrate. Reactions were performed at 37 °C with 1-100 μmol/L propafenone for 30 min. After termination, the product 5-OH-propafenone was extracted and used for signal collection by ultra-performance liquid chromatography (UPLC). Compared with wild type CYP2D6.1, the intrinsic clearance (Vmax and Km) values of all variants were significantly altered. Three variants (CYP2D6.87, CYP2D6.90, CYP2D6.F219S) exhibited markedly increased intrinsic clearance values (129% to 165%), whereas 21 variants exhibited significantly decreased values (16% to 85%) due to increased Km and (or) decreased Vmax values. These results indicated that the majority of tested alleles had significantly altered catalytic activity towards propafenone hydroxylation in this expression system. Attention should be paid to subjects carrying these rare alleles when treated with propafenone.