Dronedarone for the Treatment of Atrial Fibrillation with Concomitant Heart Failure with Preserved and Mildly Reduced Ejection Fraction: Post-Hoc Analysis of the ATHENA Trial

2024 update in heart failure

In the last years, major progress has occurred in heart failure (HF) management. The 2023 ESC focused update of the 2021 HF guidelines introduced new key recommendations based on the results of the last years of science. First, two drugs, sodium-glucose co-transporter-2 (SGLT2) inhibitors and finerenone, a novel nonsteroidal, selective mineralocorticoid receptor antagonist (MRA), are recommended for the prevention of HF in patients with diabetic chronic kidney disease (CKD). Second, SGLT2 inhibitors are now recommended for the treatment of HF across the entire left ventricular ejection fraction spectrum. The benefits of quadruple therapy in patients with HF with reduced ejection fraction (HFrEF) are well established. Its rapid and early up-titration along with a close follow-up with frequent clinical and laboratory re-assessment after an episode of acute HF (the so-called 'high-intensity care' strategy) was associated with better outcomes in the STRONG-HF trial. Patients experiencing an episode of worsening HF might require a fifth drug, vericiguat. In the STEP-HFpEF-DM and STEP-HFpEF trials, semaglutide 2.4 mg once weekly administered for 1 year decreased body weight and significantly improved quality of life and the 6 min walk distance in obese patients with HF with preserved ejection fraction (HFpEF) with or without a history of diabetes. Further data on safety and efficacy, including also hard endpoints, are needed to support the addition of acetazolamide or hydrochlorothiazide to a standard diuretic regimen in patients hospitalized due to acute HF. In the meantime, PUSH-AHF supported the use of natriuresis-guided diuretic therapy. Further options and most recent evidence for the treatment of HF, including specific drugs for cardiomyopathies (i.e., mavacamten in hypertrophic cardiomyopathy and tafamidis in transthyretin cardiac amyloidosis), device therapies, cardiac contractility modulation and percutaneous treatment of valvulopathies, with the recent finding from the TRILUMINATE Pivotal trial, are also reviewed in this article.

Device therapy for patients with atrial fibrillation and heart failure with preserved ejection fraction

Device therapy is a nonpharmacological approach that presents a crucial advancement for managing patients with atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF). This review investigated the impact of device-based interventions and emphasized their potential for optimizing treatment for this complex patient demographic. Cardiac resynchronization therapy, augmented by atrioventricular node ablation with His-bundle pacing or left bundle-branch pacing, is effective for enhancing cardiac function and establishing atrioventricular synchrony. Cardiac contractility modulation and vagus nerve stimulation represent novel strategies for increasing myocardial contractility and adjusting the autonomic balance. Left ventricular expanders have demonstrated short-term benefits in HFpEF patients but require more investigation for long-term effectiveness and safety, especially in patients with AF. Research gaps regarding complications arising from left ventricular expander implantation need to be addressed. Device-based therapies for heart valve diseases, such as transcatheter aortic valve replacement and transcatheter edge-to-edge repair, show promise for patients with AF and HFpEF, particularly those with mitral or tricuspid regurgitation. Clinical evaluations show that these device therapies lessen AF occurrence, improve exercise tolerance, and boost left ventricular diastolic function. However, additional studies are required to perfect patient selection criteria and ascertain the long-term effectiveness and safety of these interventions. Our review underscores the significant potential of device therapy for improving the outcomes and quality of life for patients with AF and HFpEF.

Cardiac-Targeting Peptide: From Discovery to Applications

Despite significant strides in prevention, diagnosis, and treatment, cardiovascular diseases remain the number one cause of mortality in the United States, with rates climbing at an alarming rate in the developing world. Targeted delivery of therapeutics to the heart has been a lofty goal to achieve with strategies ranging from direct intra-cardiac or intra-pericardial delivery, intra-coronary infusion, to adenoviral, lentiviral, and adeno-associated viral vectors which have preference, if not complete cardio-selectivity, for cardiac tissue. Cell-penetrating peptides (CPP) are 5-30-amino-acid-long peptides that are able to breach cell membrane barriers while carrying cargoes up to several times their size, in an intact functional form. Identified nearly three decades ago, the first of these CPPs came from the HIV coat protein transactivator of transcription. Although a highly efficient CPP, its clinical utility is limited by its robust ability to cross any cell membrane barrier, including crossing the blood-brain barrier and transducing neuronal tissue non-specifically. Several strategies have been utilized to identify cell- or tissue-specific CPPs, one of which is phage display. Using this latter technique, we identified a cardiomyocyte-targeting peptide (CTP) more than a decade ago, a finding that has been corroborated by several independent labs across the world that have utilized CTP for a myriad of different purposes in pre-clinical animal models. The goal of this publication is to provide a comprehensive review of the identification, validation, and application of CTP, and outline its potential in diagnostic and therapeutic applications especially in the field of targeted RNA interference.

Tic-Tac: A Translational Approach in Mechanisms Associated with Irregular Heartbeat and Sinus Rhythm Restoration in Atrial Fibrillation Patients

Atrial fibrillation (AF) is a prevalent cardiac condition predominantly affecting older adults, characterized by irregular heartbeat rhythm. The condition often leads to significant disability and increased mortality rates. Traditionally, two therapeutic strategies have been employed for its treatment: heart rate control and rhythm control. Recent clinical studies have emphasized the critical role of early restoration of sinus rhythm in improving patient outcomes. The persistence of the irregular rhythm allows for the progression and structural remodeling of the atria, eventually leading to irreversible stages, as observed clinically when AF becomes permanent. Cardioversion to sinus rhythm alters this progression pattern through mechanisms that are still being studied. In this review, we provide an in-depth analysis of the pathophysiological mechanisms responsible for maintaining AF and how they are modified during sinus rhythm restoration using existing therapeutic strategies at different stages of clinical investigation. Moreover, we explore potential future therapeutic approaches, including the promising prospect of gene therapy.

Cardiomyocyte-Targeting Peptide to Deliver Amiodarone

BACKGROUND

Amiodarone is underutilized due to significant off-target toxicities. We hypothesized that targeted delivery to the heart would lead to the lowering of the dose by utilizing a cardiomyocyte-targeting peptide (CTP), a cell-penetrating peptide identified by our prior phage display work.

METHODS

CTP was synthesized thiolated at the N-terminus, conjugated to amiodarone via Schiff base chemistry, HPLC purified, and confirmed with MALDI/TOF. The stability of the conjugate was assessed using serial HPLCs. Guinea pigs (GP) were injected intraperitoneally daily with vehicle (7 days), amiodarone (7 days; 80 mg/kg), CTP-amiodarone (5 days; 26.3 mg/kg), or CTP (5 days; 17.8 mg/kg), after which the GPs were euthanized, and the hearts were excised and perfused on a Langendorff apparatus with Tyrode's solution and blebbistatin (5 µM) to minimize the contractions. Voltage (RH237) and Ca2+-indicator dye (Rhod-2/AM) were injected, and fluorescence from the epicardium split and was captured by two cameras at 570-595 nm for the cytosolic Ca2+ and 610-750 nm wavelengths for the voltage. Subsequently, the hearts were paced at 250 ms with programmed stimulation to measure the changes in the conduction velocities (CV), action potential duration (APD), and Ca2+ transient durations at 90% recovery (CaTD90). mRNA was extracted from all hearts, and RNA sequencing was performed with results compared to the control hearts.

RESULTS

The CTP-amiodarone remained stable for up to 21 days at 37 °C. At ~1/15th of the dose of amiodarone, the CTP-amiodarone decreased the CV in hearts significantly compared to the control GPs (0.92 ± 0.05 vs. 1.00 ± 0.03 ms, p = 0.0007), equivalent to amiodarone alone (0.87 ± 0.08 ms, p = 0.0003). Amiodarone increased the APD (192 ± 5 ms vs. 175 ± 8 ms for vehicle, p = 0.0025), while CTP-amiodarone decreased it significantly (157 ± 16 ms, p = 0.0136), similar to CTP alone (155 ± 13 ms, p = 0.0039). Both amiodarone and CTP-amiodarone significantly decreased the calcium transients compared to the controls. CTP-amiodarone and CTP decreased the CaTD90 to an extent greater than amiodarone alone (p < 0.001). RNA-seq showed that CTP alone increased the expression of DHPR and SERCA2a, while it decreased the expression of the proinflammatory genes, NF-kappa B, TNF-α, IL-1β, and IL-6.

CONCLUSIONS

Our data suggest that CTP can deliver amiodarone to cardiomyocytes at ~1/15th the total molar dose of the amiodarone needed to produce a comparable slowing of CVs. The ability of CTP to decrease the AP durations and CaTD90 may be related to its increase in the expression of Ca-handling genes, which merits further study.

Cardiomyocyte Targeting Peptide to Deliver Amiodarone

Background

Amiodarone is underutilized due to significant off-target toxicities. We hypothesized that targeted delivery to the heart would lead to lowering of dose by utilizing a cardiomyocyte targeting peptide (CTP), a cell penetrating peptide identified by our prior phage display work.

Methods

CTP was synthesized thiolated at the N-terminus, conjugated to amiodarone via Schiff base chemistry, HPLC purified and confirmed with MALDI/TOF. Stability of the conjugate was assessed using serial HPLCs. Guinea pigs (GP) were injected intraperitoneally daily with vehicle (7 days), amiodarone (7 days; 80mg/Kg), CTP-amiodarone (5 days;26.3mg/Kg), or CTP (5 days; 17.8mg/Kg), after which GPs were euthanized, hearts excised, perfused on a Langendorff apparatus with Tyrode's solution and blebbistatin (5μM) to minimize contractions. Voltage (RH237) and Ca 2+ -indicator dye (Rhod-2/AM) were injected, fluorescence from the epicardium split and focused on two cameras capturing at 570-595nm for cytosolic Ca 2+ and 610-750nm wavelengths for voltage. Subsequently, hearts were paced at 250ms with programmed stimulation to measure changes in conduction velocities (CV), action potential duration (APD) and Ca 2+ transient durations at 90% recovery (CaTD 90 ). mRNA was extracted from all hearts and RNA sequencing performed with results compared to control hearts.

Results

CTP-amiodarone remained stable for up to 21 days at 37°C. At ∼1/15 th of the dose of amiodarone, CTP-amiodarone decreased CV in hearts significantly compared to control GPs (0.92±0.05 vs. 1.00±0.03m/s, p=0.0007), equivalent to amiodarone alone (0.87±0.08ms, p=0.0003). Amiodarone increased APD (192±5ms vs. 175±8ms for vehicle, p=0.0025), while CTP-amiodarone decreased it significantly (157±16ms, p=0.0136) similar to CTP alone (155±13ms, p=0.0039). Both amiodarone and CTP-amiodarone significantly decreased calcium transients compared to controls. CTP-amiodarone and CTP decreased CaTD 90 to an extent greater than amiodarone alone (p<0.001). RNA-seq showed that CTP alone increased the expression of DHPR and SERCA2a, while decreasing expression of proinflammatory genes NF-kappa B, TNF-α, IL-1β, and IL-6.

Conclusions

Our data suggests that CTP can deliver amiodarone to cardiomyocytes at ∼1/15 th the total molar dose of amiodarone needed to produce comparable slowing of CVs. The ability of CTP to decrease AP durations and CaTD 90 may be related to its increase in expression of Ca-handling genes, and merits further study.

Effect of Prolonged Use of Dronedarone on Recurrence in Patients with Non-Paroxysmal Atrial Fibrillation After Radiofrequency Ablation (DORIS): Rationale and Design of a Randomized Multicenter, Double-Blinded Placebo-Controlled Trial

BACKGROUND

Prolonged use of anti-arrhythmic drugs (AAD) beyond the post-ablation blanking period to maintain sinus rhythm has been adopted in clinical practice but without sufficient evidence. Dronedarone is an AAD valid for maintaining sinus rhythm with fewer side effects than other AAD for long-term use.

OBJECTIVE

We sought to investigate the effect of prolonged use of dronedarone on the recurrence of non-paroxysmal AF patients beyond 3 months within the first year after ablation.

METHODS

Non-paroxysmal AF patients will receive dronedarone for 3 months after radiofrequency ablation. Patients without drug side effects and atrial tachyarrhythmia (AT) recurrence will then be randomly divided into dronedarone and placebo groups and followed up until 1 year after ablation. The primary endpoint is the cumulative nonrecurrence rate post 3 months to 1 year after ablation. Patients will receive 7-day Holter monitoring (ECG patch) at 6, 9, and 12 months after ablation to evaluate AT recurrence. Secondary endpoints include dronedarone withdrawal due to side effects or intolerance of AT recurrence, time to the first recurrence, repeat ablation, electrical cardioversion, unscheduled emergency room visit, or re-hospitalization.

CONCLUSION

This trial will evaluate whether prolonged use of dronedarone effectively reduces the recurrence rate after ablation in non-paroxysmal AF patients. The result of this trial will provide evidence for optimizing post-ablation anti-arrhythmic therapy.

TRIAL REGISTRATION

ClinicalTrials.gov ; NCT05655468, 19-December-2022.

How to Manage Heart Failure With Preserved Ejection Fraction: Practical Guidance for Clinicians

Although patients with heart failure with preserved ejection fraction (HFpEF) (left ventricular ejection fraction ≥50%) comprise nearly half of those with chronic heart failure, evidence-based treatment options for this population have historically been limited. Recently, however, emerging data from prospective, randomized trials enrolling patients with HFpEF have greatly altered the range of pharmacologic options to modify disease progression in selected patients with HFpEF. In the context of this evolving landscape, clinicians are increasingly in need of practical guidance regarding the best approach to management of this growing population. In this review, we build on the recently published heart failure guidelines by integrating contemporary data from recent randomized trials to provide a contemporary framework for diagnosis and evidence-based treatment of patients with HFpEF. Where gaps in knowledge persist, we provide "best available" data from post hoc analyses of clinical trials or data from observational studies to guide management until more definitive studies are available.

Intersection of atrial fibrillation and heart failure with mildly reduced and preserved ejection fraction in >400 000 participants in the Get With The Guidelines-Heart Failure Registry

AIMS

Although atrial fibrillation (AF) frequently coexists with heart failure with preserved ejection fraction (HFpEF), few data are available evaluating AF-specific care patterns and post-discharge outcomes in patients hospitalized for HFpEF. We evaluated AF-specific medical therapies and post-discharge outcomes among patients hospitalized for heart failure with mildly reduced ejection fraction (HFmrEF) or HFpEF by AF history.

METHODS AND RESULTS

Trends in AF prevalence were evaluated among patients hospitalized for HFmrEF or HFpEF in the Get With The Guidelines-Heart Failure Registry from 2014 to 2020. Among those with linked Centers for Medicare & Medicaid Services post-discharge data, we assessed associations of AF with 12-month outcomes and determined trends in post-discharge prescriptions. Among 429 464 patients (median age 76 years [interquartile range 65-85], 57% women), 216 486 (50%) had a history of AF. Over time, the proportion of patients with AF increased slightly. Among the 79 895 patients with post-discharge data, AF was independently associated with higher risk of mortality and all-cause readmissions at 12 months, with stronger associations in HFpEF than in HFmrEF (mortality hazard ratio [HR] 1.13, 95% confidence interval [CI] 1.09-1.16 vs. HR 1.03, 95% CI 0.97-1.10; pinteraction  = 0.009). Anti-arrhythmic drug use after heart failure hospitalization was low (18%) and increased modestly over time. Amiodarone accounted for 71% of total anti-arrhythmic drug prescriptions. Overall use of anticoagulants after heart failure hospitalization has significantly increased from 52% in 2014 to 61% in 2019, but remained modest.

CONCLUSION

Prevalence of AF is rising among patients hospitalized with HFpEF. Those with comorbid AF face elevated post-discharge risks of death and rehospitalization. Current use of pharmacological rhythm control is low.

Heart failure: an update from the last years and a look at the near future

In the last years, major progress occurred in heart failure (HF) management. Quadruple therapy is now mandatory for all the patients with HF with reduced ejection fraction. Whilst verciguat is becoming available across several countries, omecamtiv mecarbil is waiting to be released for clinical use. Concurrent use of potassium-lowering agents may counteract hyperkalaemia and facilitate renin-angiotensin-aldosterone system inhibitor implementations. The results of the EMPagliflozin outcomE tRial in Patients With chrOnic heaRt Failure With Preserved Ejection Fraction (EMPEROR-Preserved) trial were confirmed by the Dapagliflozin in Heart Failure with Mildly Reduced or Preserved Ejection Fraction (DELIVER) trial, and we now have, for the first time, evidence for treatment of also patients with HF with preserved ejection fraction. In a pre-specified meta-analysis of major randomized controlled trials, sodium-glucose co-transporter-2 inhibitors reduced all-cause mortality, cardiovascular (CV) mortality, and HF hospitalization in the patients with HF regardless of left ventricular ejection fraction. Other steps forward have occurred in the treatment of decompensated HF. Acetazolamide in Acute Decompensated Heart Failure with Volume Overload (ADVOR) trial showed that the addition of intravenous acetazolamide to loop diuretics leads to greater decongestion vs. placebo. The addition of hydrochlorothiazide to loop diuretics was evaluated in the CLOROTIC trial. Torasemide did not change outcomes, compared with furosemide, in TRANSFORM-HF. Ferric derisomaltose had an effect on the primary outcome of CV mortality or HF rehospitalizations in IRONMAN (rate ratio 0.82; 95% confidence interval 0.66-1.02; P = 0.070). Further options for the treatment of HF, including device therapies, cardiac contractility modulation, and percutaneous treatment of valvulopathies, are summarized in this article.

Effect of Dronedarone in the Treatment of Atrial Fibrillation in the Asian Population: Post Hoc Analysis of the ATHENA Trial

PURPOSE

Limited data are available on the impact of dronedarone treatment in Asian patients with atrial fibrillation (AF) or atrial flutter (AFL). This post hoc analysis evaluated the efficacy and safety of dronedarone compared with placebo in populations from Asian and non-Asian regions randomized in the ATHENA trial (A Placebo-Controlled, Double-blind, Parallel Arm Trial to Assess the Efficacy of Dronedarone 400 mg BID for the Prevention of CV Hospitalization or Death From Any Cause in Patients With AF/AFL).

METHODS

Time to first hospitalization for cardiovascular events or death from any cause (primary outcome) and time to first AF/AFL event recurrence (secondary outcome) were analyzed by Kaplan-Meier curves and Cox proportional hazards regression.

FINDINGS

The risk of experiencing the primary composite outcome was significantly lower in the dronedarone-treated patients in both the Asian (hazard ratio = 0.541; 95% CI, 0.320-0.914]) and non-Asian (hazard ratio = 0.768; 95% CI, 0.696-0.848) populations than in the placebo-treated patients. The median time to the first AF/AFL event recurrence was longer in the dronedarone-treated population than in the placebo-treated populations: 183 vs 92 days (P = 0.165) in the Asian population and 534 vs 196 days (P < 0.001) in the non-Asian population. Treatment-emergent adverse events in Asian (81.2% vs 78.4%) and non-Asian (71.4% vs 68.7%) populations and serious treatment-emergent adverse events in Asian (14.3% vs 15.7%) and non-Asian (20.3% vs 21.5%) patients were comparable in patients taking dronedarone compared with those taking placebo.

IMPLICATION

Efficacy and tolerability of dronedarone were consistent in the Asian population compared with the non-Asian population in the ATHENA trial. These finding may aid Asian health care professionals to select the appropriate first-line treatment for Asian patients with AF/AFL.

Impact of dronedarone on patients with atrial fibrillation and diabetes: A sub-analysis of the ATHENA and EURIDIS/ADONIS studies

AIM

This post hoc analysis evaluated efficacy and safety of dronedarone in atrial fibrillation (AF) and atrial flutter (AFL) patients with/without diabetes.

METHODS

Patients were categorized according to baseline diabetes status. Time-to-event analyses were performed using Kaplan-Meier method. Hazard-ratios were assessed using Cox models.

RESULTS

945/4628 (dronedarone = 482; placebo = 463) patients in ATHENA and 215/1237 (dronedarone = 148; placebo = 67) patients in EURIDIS/ADONIS studies had diabetes. In ATHENA, there were higher rates of CV hospitalization/death in patients with diabetes (39.5%) than without diabetes (34.7%). Incidence of first CV hospitalization/death was lower in patients with diabetes treated with dronedarone (35.1%) than placebo (44.1%), and time to this event was longer in those treated with dronedarone than placebo (log-rank p = 0.005). Median AF/AFL recurrence time was longer in patients treated with dronedarone than placebo in patients with diabetes (ATHENA: 722 vs 527 days, log-rank p = 0.004; EURIDIS/ADONIS: 100 vs 23 days, log-rank p = 0.15) or without diabetes (ATHENA: 741 vs 492 days, log-rank p < 0.0001; EURIDIS/ADONIS: 120 vs 59 days, log-rank p = 0.0002). Occurrence of any treatment-related adverse events with dronedarone was similar for patients with/without diabetes and was comparable to placebo.

CONCLUSIONS

Dronedarone reduced incidence of CV hospitalization/death, AF/AFL recurrence and increased time to these events in AF/AFL patients with/without diabetes.

TRIAL REGISTRATION

Not applicable, as it was a post hoc analysis. This article is based on previously conducted studies (ATHENA: NCT00174785, EURIDIS: NCT00259428, and ADONIS: NCT00259376).