Dronedarone for the Treatment of Atrial Arrhythmias in Adults With Congenital Heart Disease

BACKGROUND

Atrial tachyarrhythmias are common and difficult to treat in adults with congenital heart disease. Dronedarone has proven effective in patients without congenital heart disease, but data are limited about its use in adults with congenital heart disease of moderate to great complexity.

METHODS

A single-center, retrospective chart review of 21 adults with congenital heart disease of moderate to great complexity who were treated with dronedarone for atrial tachyarrhythmias was performed.

RESULTS

The median (IQR) age at dronedarone initiation was 35 (27.5-39) years. Eleven patients (52%) were male. Ten patients (48%) had New York Heart Association class I disease, 10 (48%) had class II disease, and 1 (5%) had class III disease. Ejection fraction at initiation was greater than 55% in 11 patients (52%), 35% to 55% in 9 patients (43%), and less than 35% in 1 patient (5%). Prior treatments included β-blockers (71%), sotalol (38%), amiodarone (24%), digoxin (24%), and catheter ablation (38%). Rhythm control was complete in 5 patients (24%), partial in 6 (29%), and inadequate in 10 (48%). Two patients (10%) experienced adverse events, including nausea in 1 (5%) and cardiac arrest in 1 (5%), which occurred 48 months after initiation of treatment. There were no deaths during the follow-up period. The median (IQR) follow-up time for patients with complete or partial rhythm control was 20 (1-54) months.

CONCLUSION

Dronedarone can be effective for adult patients with congenital heart disease and atrial arrhythmias for whom more established therapies have failed, and with close monitoring it can be safely tolerated.

Efficacy of Shensong Yangxin capsule combined with dronedarone in paroxysmal atrial fibrillation after ablation

OBJECTIVE

To investigate whether postoperative administration of Shensong Yangxin capsules (SSYX) and dronedarone for atrial fibrillation (AF) can reduce the recurrence of paroxysmal AF after radiofrequency ablation, thus providing a more optimal choice of antiarrhythmic medication during the blank period.

METHODS

We included 120 patients with paroxysmal AF who underwent radiofrequency ablation at our hospital between July 2020 and July 2022. They underwent routine circumferential pulmonary vein ablation and, subsequently, left and right atrial pressure monitoring to assess sinoatrial node recovery time under burst 400/300 ms stimulation. Postoperatively, the patients were randomly divided into 2 groups (60 patients each). The control group was administered dronedarone orally for 3 months and the study group was treated with SSYX combined with dronedarone. This study aimed to compare differences in clinical efficacy of the treatment between the 2 groups.

RESULTS

The left and right atrial pressures in both groups were higher than those in the preoperative period (P < .05), with no statistically significant differences between the 2 groups (P > .05). Sinoatrial node recovery time under burst 400/300 ms stimulation showed no statistical difference between the 2 groups (P > .05). At 3 months and 1 year postoperatively, the AFEQT scale scores for both groups were lower than those before treatment (P < .05), with the study group scoring lower than the control group at 3 months (P < .05). However, no statistically significant difference was observed between the 2 groups at 1 year postoperatively (P > .05). At 3 months postoperatively, the sinus rhythm maintenance rate and heart rate were higher in the intervention group than in the control group (P < .05); however, these differences between the 2 groups were not statistically significant at 1 year postoperatively (P > .05).

CONCLUSION SUBSECTIONS

The combination of SSYX and dronedarone could effectively reduce the early recurrence of paroxysmal AF after radiofrequency ablation, increase heart rate, and improve the quality of life.

Chapter 2: Rate Versus Rhythm Control

Atrial fibrillation (AF) is a potentially serious health risk, both because of its symptoms and because of its association with an increased risk for heart failure, hospitalization, thromboembolism, and death. Chapter 2 discusses selection of appropriate treatments and when to initiate these therapies. Older trials focused on comparing rate versus rhythm control treatment options for AF. It is now recognized that both rate and rhythm control are important and can be used together. This chapter reviews the historical, pivotal rate versus rhythm control trials that failed to show any overall survival benefit of rhythm over rate control, as well as the trials' now-recognized limitations with respect to modern therapy. In addition, an in-depth discussion of the more recent trials of antiarrhythmic drugs (AAD) and ablation techniques (which have become available since the original rate versus rhythm trials were performed) is included. These updated trials show that when applied to patient- and disease-specific situations, rhythm control can reduce the risk for mortality and hospitalization. The chapter also reviews the guidelines that have been developed to achieve these goals. Chapter 2 is summarized as follows: (1) Rate control is needed (at rest and during exertion) to reduce rate-related symptoms when rhythm control is ineffective or incomplete and to prevent a tachycardia-induced cardiomyopathy. (2) Previous trials with pharmacological therapy alone comparing rate versus rhythm control using the AADs available at that time failed to show any overall survival benefit of rhythm control over rate control. (3) These earlier trials had many methodological limitations and enrolled participants who did not have access to modern therapies. (4) Newer therapies, including those for stroke prevention, dronedarone (the latest approved AAD), and AF ablation, have improved the safety and efficacy of rhythm control strategies.

A value-based budget impact model for dronedarone compared with other rhythm control strategies

Aim: The budgetary consequences of increasing dronedarone utilization for treatment of atrial fibrillation were evaluated from a US payer perspective. Materials & methods: A budget impact model over a 5-year time horizon was developed, including drug-related costs and risks for long-term clinical outcomes (LTCOs). Treatments included antiarrhythmic drugs (AADs; dronedarone, amiodarone, sotalol, propafenone, dofetilide, flecainide), rate control medications, and ablation. Direct comparisons and temporal and non-temporal combination scenarios investigating treatment order were analyzed as costs per patient per month (PPPM). Results: By projected year 5, costs PPPM for dronedarone versus other AADs decreased by $37.69 due to fewer LTCOs, treatment with dronedarone versus ablation or rate control medications + ablation resulted in cost savings ($359.94 and $370.54, respectively), and AADs placed before ablation decreased PPPM costs by $242 compared with ablation before AADs. Conclusion Increased dronedarone utilization demonstrated incremental cost reductions over time.

Risk of Major Bleeding in Patients With Atrial Fibrillation Taking Dronedarone in Combination With a Direct Acting Oral Anticoagulant (From a U.S. Claims Database)

Dronedarone may increase exposure and the risk of major bleeding when prescribed with a direct oral anticoagulant (DOAC). This retrospective cohort study examined the risk of the first occurrence of major bleeding (hospitalization or emergency room visit for gastrointestinal [GI] bleeding, intracranial hemorrhage [ICH], or bleeding at other sites) among new users of apixaban, dabigatran, and rivaroxaban in patients with AF ≥18 years (January 1, 2007 to September 30, 2017) from the United States Truven Health MarketScan claims, comparing concomitant users of dronedarone to DOAC alone users in patients with atrial fibrillation (AF). No increased risk of major bleeding was associated with use of dronedarone and apixaban (adjusted Hazard Ratio [aHR]: 0.69 [95% confidence interval [CI]: 0.40, 1.17], p = 0.16), a modestly increased risk of GI bleeding but not overall bleeding was associated with use of dronedarone and dabigatran (aHR bleeding: 1.18 [95% CI: 0.89, 1.56], p = 0.26; aHR GI bleeding: 1.40 [95% CI: 1.01, 1.93]; p = 0.04) and an increased risk of overall bleeding, driven by GI bleeding, was associated with use of dronedarone and rivaroxaban (aHR bleeding: 1.31 [95% CI: 1.01, 1.69]; p = 0.04; aHR GI bleeding: 1.39 [95% CI: 0.98, 1.95]; p = 0.06), compared to each DOAC respectively. There was no increased risk of ICH associated with combined use of dronedarone and any DOAC. Prospective analyses, preferably randomized controlled studies, are needed to further explore the risk of major bleeding with concomitant use of DOACs and CYP3A4/P-gp inhibitors such as dronedarone.

Outcomes Associated with Dronedarone Use in Patients with Atrial Fibrillation

The antiarrhythmic drug dronedarone was designed to reduce the extra-cardiac adverse effects associated with amiodarone use in treatment of patients with atrial fibrillation / atrial flutter (AF/AFL). This epidemiological study used a retrospective cohort design to compare risk of cardiovascular-related hospitalizations and death in AF/AFL patients treated with dronedarone versus other antiarrhythmic drugs (AADs). AF/AFL patients with incident dronedarone fills were matched by propensity score (PS) to incident users of other AADs. The primary study outcome was hospitalization for cardiovascular (CV) causes within 24 months after the first study drug fill. A secondary composite outcome comprised hospitalization for CV causes or all-cause mortality during follow-up. In the AF/AFL patient cohort meeting eligibility criteria, 6,964 incident users of dronedarone and 25 607 incident users of other AADs were identified. The PS-matched cohort comprised 6,349 Dronedarone users (91.2% of all eligible) and 12,698 other AAD users. Dronedarone patients had a significantly lower risk of hospitalization for a CV event compared to Other AAD users (hazard ratio = 0.87; 95% confidence interval = 0.79 to 0.96). This was consistent with results for the composite outcome (hazard ratio=0.86; 95% confidence interval = 0.78 to 0.95). In conclusion, AF/AFL patients initiated on dronedarone versus other AADs had significantly lower risk of CV hospitalizations as well as the composite CV hospitalization / death from any cause.

Patient and provider-level factors associated with changes in utilization of treatments in response to evidence on ineffectiveness or harm

High-quality health care not only includes timely access to effective new therapies but timely abandonment of therapies when they are found to be ineffective or unsafe. Little is known about changes in use of medications after they are shown to be ineffective or unsafe. In this study, we examine changes in use of two medications: fenofibrate, which was found to be ineffective when used with statins among patients with Type 2 diabetes (ACCORD lipid trial); and dronedarone, which was found to be unsafe in patients with permanent atrial fibrillation (PALLAS trial). We examine the patient and provider characteristics associated with a decline in use of these medications. Using Medicare fee-for-service claims from 2008 to 2013, we identified two cohorts: patients with Type 2 diabetes using statins (7 million patient-quarters), and patients with permanent atrial fibrillation (83 thousand patient-quarters). We used interrupted time-series regression models to identify the patient- and provider-level characteristics associated with changes in medication use after new evidence emerged for each case. After new evidence of ineffectiveness emerged, fenofibrate use declined by 0.01 percentage points per quarter (95% CI - 0.02 to - 0.01) from a baseline of 6.9 percent of all diabetes patients receiving fenofibrate; dronedarone use declined by 0.13 percentage points per quarter (95% CI - 0.15 to - 0.10) from a baseline of 3.8 percent of permanent atrial fibrillation patients receiving dronedarone. For dronedarone, use declined more quickly among patients dually-enrolled in Medicare and Medicaid compared to Medicare-only patients (P < 0.001), among patients seen by male providers compared to female providers (P = 0.01), and among patients seen by cardiologists compared to primary care providers (P < 0.001).

Evaluating class III antiarrhythmic agents as novel MYC targeting drugs in ovarian cancer

OBJECTIVE

To evaluate the utility of amiodarone and its derivative dronedarone as novel drug repositioning candidates in EOC and to determine the potential pathways targeted by these drugs.

METHODS

Drug-predict bioinformatics platform was used to assess the utility of amiodarone as a novel drug-repurposing candidate in EOC. EOC cells were treated with amiodarone and dronedarone. Cell death was assessed by Annexin V staining. Cell viability and cell survival were assessed by MTT and clonogenics assays respectively. c-MYC and mTOR/Akt axis were evaluated as potential targets. Effect on autophagy was determined by autophagy flux flow cytometry.

RESULTS

"DrugPredict" bioinformatics platform ranked Class III antiarrhythmic drug amiodarone within the top 3.9% of potential EOC drug repositioning candidates which was comparable to carboplatin ranking in the top 3.7%. Amiodarone and dronedarone were the only Class III antiarrhythmic drugs that decreased the cellular survival of both cisplatin-sensitive and cisplatin-resistant primary EOC cells. Interestingly, both drugs induced degradation of c-MYC protein and decreased the expression of known transcriptional targets of c-MYC. Furthermore, stable overexpression of non-degradable c-MYC partially rescued the effects of amiodarone and dronedarone induced cell death. Dronedarone induced higher autophagy flux in EOC cells as compared to amiodarone with decreased phospho-AKT and phospho-4EBP1 protein expression, suggesting autophagy induction due to inhibition of AKT/mTOR axis with these drugs. Lastly, both drugs also inhibited the survival of EOC tumor-initiating cells (TICs).

CONCLUSIONS

We provide the first evidence of class III antiarrhythmic agents as novel c-MYC targeting drugs and autophagy inducers in EOC. Since c-MYC is amplified in >40% ovarian tumors, our results provide the basis for repositioning amiodarone and dronedarone as novel c-MYC targeting drugs in EOC with potential extension to other cancers.

Ventricular arrhythmia and death among atrial fibrillation patients using anti-arrhythmic drugs

AIM

The aim of the study was to assess and compare the safety of antiarrhythmic drugs (AADs) in an unselected real-world population of patients with atrial fibrillation (AF).

METHODS AND RESULTS

This is a study of all patients with diagnosed AF in the Swedish Patient register who filled a prescription for sotalol, amiodarone, dronedarone, flecainide or disopyramide during 2010 to 2015. The main end point consisted of arrhythmic death, successful resuscitation, new diagnosis of sustained ventricular tachycardia, ventricular fibrillation or implantation of ICD. All-cause mortality was a secondary end point. Minimum follow up was 1 year. Falsification end points were used to assess hidden confounding. 44,995 AF patients on AAD and 267,518 AF patients without AAD were studied during a total time at risk of over 1.1 million years. Compared to sotalol, the risk for the main end point was decreased with dronedarone (hazard ratio [HR] 0.58, 95% confidence interval [CI] 0.37-0.90), similar with flecainide (HR 0.95, 0.69-1.32) and disopyramide (HR 1.30, CI 0.83-2.05). All-cause mortality was lower with dronedarone (HR 0.44, CI 0.34-0.57) and flecainide (HR 0.55, CI 0.44-0.68) than with sotalol. Hidden confounding prevented reliable assessment of amiodarone.

CONCLUSIONS

Dronedarone was the only anti-arrhythmic drug with significantly lower risk for arrhythmic death, sustained ventricular arrhythmia or ICD implantation than sotalol among patients with atrial fibrillation. Both dronedarone and flecainide were associated with lower all-cause mortality than sotalol.