Predictors of successful cardioversion of recent-onset atrial fibrillation to sinus rhythm with orally inhaled flecainide

Background

Height, weight, and body mass index (BMI) are well established risk factors for atrial fibrillation (AF) but whether they are also predictors of successful pharmacological cardioversion of AF is unknown. Data from the open-label INSTANT study of flecainide acetate oral inhalation solution (FlecIH) for acute cardioversion of recent-onset symptomatic AF were examined to determine if these anthropometric measures are predictors of successful cardioversion of AF to sinus rhythm (SR) with FlecIH.

Methods

Logistic regression was performed on a broad array of patient and disease characteristics to identify predictors of cardioversion success at 90 minutes post-dose, and potential interactions were examined by boundary restriction analysis. Data are presented for patients receiving 120 mg FlecIH.

Results

Data from 81 patients (32.1% female) with a mean age of 59.8 years (range: 26.0, 84.0) were included in the analysis. This cohort had a mean weight of 87 kg (range: 57, 150), a mean height of 180 cm (range: 156, 199), and a mean BMI of 26.8 kg/m2 (range: 17.2, 37.9). A logistic regression model identified height, weight, and BMI as significant predictors of cardioversion success (p<0.01) and a boundary restriction analysis revealed a negative correlation between BMI and conversion rate across the entire dataset (see Figure 1). Clinically significant conversion rates were observed for patients with BMI values that were considered normal (BMI <25 kg/m2 = 53%; 95% CI: 36, 70), overweight (BMI ≥25 and <30 kg/m2 = 47%; 95% CI: 29, 64), and obese (BMI ≥30 and <35 kg/m2 = 43%; 95% CI: 17, 69); however, none of the severely obese patients (BMI ≥35 mg/m2) had their AF successfully converted to sinus rhythm (see Figure 2).

Conclusions

Successful cardioversion of recent onset AF with 120 mg FlecIH was observed in normal, overweight, and obese patients with BMI values <35 kg/m2; however, conversion rate decreases with increasing BMI. Further evaluation of FlecIH dosing in severely obese patients is warranted.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): InCarda Therapeutics

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Replicated gene expression changes in patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union Horizon 2020 CATCH ME; Cardiovascular Research Netherlands RACE V

Background

Little is known about changes in the atrial transcriptome associated with paroxysmal and persistent atrial fibrillation (AF).

Purpose

To identify major molecular mechanisms in AF, we determined consistent differential expression (DE) between atrial tissue samples from well-characterized patients with paroxysmal or persistent AF and patients without a history of AF (no AF) in two independent patient cohorts.

Methods

Poly-A tailed RNA from left and right atrial appendage tissue samples from independent discovery and replication cohorts CATCH ME (n=192) and RACE V (n=122) was sequenced and analyzed according to patient AF history. Analyses were performed stratified by atrial side, adjusting for age, sex, heart failure and a combination of clinical characteristics determined by principal component analysis. Transcripts were considered DE in CATCH ME if their fold change reached transcriptome-wide significance (false discovery rate (FDR) < 0.05). DE transcripts in each rhythm comparison were replicated in RACE V if we observed a concordant direction of effect and a within-set FDR < 0.05 in the same comparison.

Results

Persistent AF compared to no AF was associated with 184 left atrial DE transcripts in CATCH ME of which 85 (46%) were replicated in RACE V, and with 208 right atrial DE transcripts in CATCH ME of which 86 (41%) were replicated in RACE V. Overall, 26 transcripts were discovered and replicated in both atria. Discovered but non-replicated transcripts often did exhibit concordant direction of effect (left: 78%, right: 83%). Replicated transcripts consisted of protein coding genes, antisense and non-coding RNAs. Protein coding genes showed involvement in pathways linking persistent AF to cardiomyocyte structure, conduction properties, fibrosis, inflammation, molecule trafficking, and endothelial dysfunction. Interestingly, paroxysmal AF was not consistently associated with DE transcripts in any comparison. Principal component analysis of the expression of the 26 transcripts strongly associated with persistent AF did however reveal a distinct paroxysmal AF expression profile in-between no AF and persistent AF patients in the first principal component scores (Figure 1).

Conclusion

RNA sequencing of human atrial tissue samples identified many transcripts associated with persistent AF in left and/or right atria, discovered and replicated using two independent cohorts. These consistent findings of AF-induced changes provide a starting point for targeted proteomic analysis and single-nucleus sequencing to further unravel the molecular mechanisms underlying AF progression to persistent AF, and biomarker development to quantify AF progression and enable precision medicine in individual patients.

The TeleCheck-AF project on remote app-based management of atrial fibrillation during the COVID-19 pandemic: Patient experiences

Funding Acknowledgements

OnBehalf

Aims

Methods

Results

Conclusions

Atrial function discriminates paroxysmal AF patients with HFpEF from those without HFpEF: subanalysis from AF-RISK study

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie. Grant support from the Dutch Heart Foundation [NHS2010B233]

Background. Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) are two cardiovascular conditions that often coexist. Overlapping symptoms, biomarker profile, and echocardiographic changes hinder the diagnosis of underlying HFpEF in patients with AF and suggest that both conditions might reflect similar remodelling processes in the heart.

Purpose. To assess cardiac remodelling in AF patients with versus without concomitant HFpEF by transthoracic echocardiography, focusing on atrial dimension and strain.

Methods. We selected 120 patients included in AF-RISK, a prospective, observational, multicentre study aiming to identify a risk profile to guide atrial fibrillation therapy study. Patients had paroxysmal AF diagnosed within three years before inclusion, had a left ventricular ejection fraction (LVEF) ≥50% and were in sinus rhythm at the moment of performing echocardiography and blood sampling. Patients were matched by nearest neighbour by age and sex with a 1:1 ratio and were classified into two groups: 1) AF with HFpEF (n = 60) and 2) AF without HFpEF (n = 60). The diagnosis of HFpEF was based on the 2016 ESC heart failure guidelines, including symptoms and signs of heart failure, N-terminal pro-B-type natriuretic peptide (NT-proBNP) ≥125pg/ml, and one of the following echocardiographic measures: left atrium volume index (LAVI) >34ml/m2, left ventricular mass index ≥115g/m2 for men and ≥95g/m2 for women, average E/e’ ≥13cm/s and average e’ <9cm/s. Measurements of reservoir, conduit and contraction strain of both atria were performed in apical four-chamber by echocardiography (GE, EchoPac BT12). Associations of clinical and echocardiographic characteristics were tested for collinearity by multivariable logistic regression analyses. LAVI, LV mass index and NT-proBNP were excluded from multivariable analysis since these markers were part of the HFpEF diagnostic criteria.

Results. Patients with paroxysmal AF and concomitant HFpEF had more often hypertension (72% vs. 45%, P = 0.005), had more impaired strain phases of both the left and right atria (figure 1), had comparable LVEF and global longitudinal strain (GLS) (P = 0.168 and P = 0.212, respectively). In a model adjusted for the number of comorbidities and sex, LA contraction decrease was associated with presence of HFpEF (odds ratio per 1% LA contraction-percent was 0.94, 95% confidence interval 0.87–0.99, P = 0.042). LA contraction was not explained by LAVI in patients with concomitant HFpEF (Spearman’s rho= -0.07, P = 0.08). Conclusion. Our results show that atrial function may differentiate paroxysmal AF patients with HFpEF from those without HFpEF. In patients with paroxysmal AF, more impaired strain phases of the left and right atria were associated with concomitant HFpEF, whereas ventricular function, reflected by LVEF and GLS, did not differ. Abstract Figure. Strain distribution of both atria

Remote app-based management of atrial fibrillation during the COVID-19: The centre characteristics and experiences of the European TeleCheck-AF project

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

TeleCheck-AF Investigators

Aims

Herein we describe the characteristics, inclusion rates and experiences from participating centres in the European TeleCheck-AF project. TeleCheck-AF is a multicentre international project initiated to maintain care delivery for patients with atrial fibrillation (AF) during COVID-19 through teleconsultations supported by an on-demand photoplethysmography-based heart rate and rhythm monitoring app (FibriCheck®). 

Methods

Two surveys exploring centre characteristics (n = 25) and centre experiences (n = 23) were completed.

Results

Most centres were academic (64%) and specialized public cardiology/district hospitals (36%). Majority of centres had AF outpatient clinics (64%) and only 36% had AF ablation clinics. The time required to start patient inclusion and total number of included patients in the project was comparable for centres experienced (56%) or inexperienced in mHealth use. Within 28 weeks, 1930 AF patients were recruited, mainly for remote AF control (31% of patients) and AF ablation follow-up (42%). Average inclusion rate was highest during the lockdown restrictions and reached a steady state at a lower level after easing the restrictions (188 vs 52 weekly recruited patients). Majority (>80%) of the centres reported no problems during the implementation of the TeleCheck-AF approach. Centres agreed that the on-boarding process of their center in the TeleCheck-AF project was simple and access to the patients measurements via stand-alone cloud infrastructure was trouble-free and possible from the first day on. They also agreed that remote heart rate and rhythm assessment by the FibriCheck® app around teleconsulatation supported their medical decision making; that their patients responded positively to use FibriCheck® for seven days; and that they felt comfortable to interpret PPG recordings. 

Conclusions

Despite different health care settings and mHealth experiences, the TeleCheck-AF approach could be set up within an extremely short time and easily used in different European centres during COVID-19.

Reappraisal of Atrial fibrillation: interaction between hyperCoagulability, Electrical remodelling and Vascular destabilisation in the progression of AF (RACE V) Tissue Bank Project: study design

Background

The development of atrial fibrillation (AF) is a complex multifactorial process. Over the past few decades, much has been learned about the pathophysiological processes that can lead to AF from a variety of specific disease models in animals. However, our ability to recognise these disease processes in AF patients is still limited, which has contributed to the limited progress in improving rhythm control in AF.

Aims/objectives

We believe that a better understanding and detection of the individual pathophysiological mechanisms underlying AF is a prerequisite for developing patient-tailored therapies. The RACE V Tissue Bank Project will contribute to the unravelling of the main molecular mechanisms of AF by studying histology and genome-wide RNA expression profiles and combining this information with detailed phenotyping of patients undergoing cardiac surgery.

Methods

As more and more evidence suggests that AF may occur not only during the first days but also during the months and years after surgery, we will systematically study the incidence of AF during the first years after cardiac surgery in patients with or without a history of AF. Both the overall AF burden as well as the pattern of AF episodes will be studied. Lastly, we will study the association between the major molecular mechanisms and the clinical presentation of the patients, including the incidence and pattern of AF during the follow-up period.

Conclusion

The RACE V Tissue Bank Project combines deep phenotyping of patients undergoing cardiac surgery, including rhythm follow-up, analysis of molecular mechanisms, histological analysis and genome-wide RNA sequencing. This approach will provide detailed insights into the main pathological alterations associated with AF in atrial tissue and thereby contribute to the development of individualised, mechanistically informed patient-tailored treatment for AF.

Efficacy and safety of dronedarone vs placebo in patients with atrial fibrillation or atrial flutter across a spectrum of renal function: post hoc analyses of the EURIDIS-ADONIS trials

Background/Introduction

The use of antiarrhythmic drugs in patients with chronic kidney disease (CKD) is complex because impaired renal clearance can cause increased drug levels, and risk of intolerance or adverse events. Since CKD commonly co-occurs with atrial fibrillation/atrial flutter (AF/AFL), it is important to establish efficacy and safety for such drugs when used in AF/AFL patients with CKD.

Purpose

To evaluate the efficacy and safety of dronedarone in patients with AF or AFL across different levels of renal function.

Methods

This post hoc analysis evaluated pooled data from two multicentre, double-blind, randomised (2:1) trials of rhythm control with dronedarone 400 mg twice daily vs placebo. Primary endpoint was time to first recurrence of AF or AFL. Renal function (estimated glomerular filtration rate [eGFR]) was assessed with the CKD-Epidemiology Collaboration equation. Patients were grouped by eGFR strata. Log-rank testing and Cox regression were used to compare time to events between treatment groups.

Results

Most (85%) patients had mild or mild-to-moderate decrease in eGFR (Table 1). Median time to first AF recurrence was significantly longer in the dronedarone vs placebo group for all eGFR subgroups except the 30–44 mL/min group (Figure 1), where the trend was consistent; however, the small population size may have precluded meaningful analyses in this subgroup. Serious adverse events, deaths, and treatment discontinuations did not differ notably between each group irrespective of eGFR strata.

Conclusions

This analysis confirms the efficacy and safety of dronedarone in patients with AF across a wide spectrum of renal function.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Sanofi

EHRA White Paper: knowledge gaps in arrhythmia management—status 2019

Clinicians accept that there are many unknowns when we make diagnostic and therapeutic decisions. Acceptance of uncertainty is essential for the pursuit of the profession: bedside decisions must often be made on the basis of incomplete evidence. Over the years, physicians sometimes even do not realize anymore which the fundamental gaps in our knowledge are. As clinical scientists, however, we have to halt and consider what we do not know yet, and how we can move forward addressing those unknowns. The European Heart Rhythm Association (EHRA) believes that scanning the field of arrhythmia / cardiac electrophysiology to identify knowledge gaps which are not yet the subject of organized research, should be undertaken on a regular basis. Such a review (White Paper) should concentrate on research which is feasible, realistic, and clinically relevant, and should not deal with futuristic aspirations. It fits with the EHRA mission that these White Papers should be shared on a global basis in order to foster collaborative and needed research which will ultimately lead to better care for our patients. The present EHRA White Paper summarizes knowledge gaps in the management of atrial fibrillation, ventricular tachycardia/sudden death and heart failure.

Integrating new approaches to atrial fibrillation management: the 6th AFNET/EHRA Consensus Conference

There are major challenges ahead for clinicians treating patients with atrial fibrillation (AF). The population with AF is expected to expand considerably and yet, apart from anticoagulation, therapies used in AF have not been shown to consistently impact on mortality or reduce adverse cardiovascular events. New approaches to AF management, including the use of novel technologies and structured, integrated care, have the potential to enhance clinical phenotyping or result in better treatment selection and stratified therapy. Here, we report the outcomes of the 6th Consensus Conference of the Atrial Fibrillation Network (AFNET) and the European Heart Rhythm Association (EHRA), held at the European Society of Cardiology Heart House in Sophia Antipolis, France, 17-19 January 2017. Sixty-two global specialists in AF and 13 industry partners met to develop innovative solutions based on new approaches to screening and diagnosis, enhancing integration of AF care, developing clinical pathways for treating complex patients, improving stroke prevention strategies, and better patient selection for heart rate and rhythm control. Ultimately, these approaches can lead to better outcomes for patients with AF.

Potential net clinical benefit of population-wide implementation of apixaban and dabigatran among European patients with atrial fibrillation

Vitamin K antagonists (e.g. warfarin) are commonly underutilised, due to limitations such as the need for monitoring, in high-risk atrial fibrillation (AF) patients. We therefore aimed to model the potential impact on clinical outcomes in patients with AF with the use of the novel oral anticoagulant (OAC) drugs, apixaban and dabigatran. We identified all high-risk (CHA2DS2-VASc score ≥2) patients with non-valvular AF and known one-year follow-up from the EuroHeart Survey on AF (EHS-AF). We modelled the expected numbers of clinical events on the novel OACs using published hazard ratios from their respective phase 3 clinical trials and calculated the numbers needed to treat and the mathematical net clinical benefit. Our analysis included 3,400 patients [39% females; mean (SD) age 67 (12) years; CHA2DS2-VASc score 3.0 (1.8)] of which 330 were excluded from the modelling analysis due to concomitant use of OAC and antiplatelet drugs. During one-year follow- up, 108 (3.2%) patients experienced thromboembolism, 51 (1.5%) major bleeds and 146 (4.3%) died. Compared to current treatments (i.e. warfarin, aspirin or nothing) the use of apixaban in highrisk patients would have potentially prevented an additional 17 deaths, 27 strokes and eight major bleeds within this cohort. With use of dabigatran 150 mg BID, 34 strokes could have been prevented and for dabigatran110 mg BID, 16 strokes and six major bleeds would be avoided. Extrapolation of the data from the EHS-AF to the whole of Europe would translate into the prevention of an additional 64,573 major cardiovascular events and deaths each year among patients with a CHA2DS2-VASc ≥2, by the use of apixaban, 43,235 with the use of dabigatran 150 mg bid and 27,272 with the use of dabigatran 110 mg bid. In conclusion, based on this modelling exercise, the utilisation of apixaban and dabigatran for thromboprophylaxis could provide a profound annual mathematical net clinical benefit on stroke and major bleeds, in European AF patients.

Note: The editorial process for this paper was fully handled by Prof. C. Weber, Editor in Chief.

Screening for Atrial Fibrillation

Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.

Acute cardioversion vs a wait-and-see approach for recent-onset symptomatic atrial fibrillation in the emergency department: Rationale and design of the randomized ACWAS trial

BACKGROUND

Current standard of care for patients with recent-onset atrial fibrillation (AF) in the emergency department aims at urgent restoration of sinus rhythm, although paroxysmal AF is a condition that resolves spontaneously within 24 hours in more than 70% of the cases. A wait-and-see approach with rate-control medication only and when needed cardioversion within 48 hours of onset of symptoms is hypothesized to be noninferior, safe, and cost-effective as compared with current standard of care and to lead to a higher quality of life.

DESIGN

The ACWAS trial (NCT02248753) is an investigator-initiated, randomized, controlled, 2-arm noninferiority trial that compares a wait-and-see approach to the standard of care. Consenting adults with recent-onset symptomatic AF in the emergency department without urgent need for cardioversion are eligible for participation. A total of 437 patients will be randomized to either standard care (pharmacologic or electrical cardioversion) or the wait-and-see approach, consisting of symptom reduction through rate control medication until spontaneous conversion is achieved, with the possibility of cardioversion within 48 hours after onset of symptoms. Primary end point is the presence of sinus rhythm on 12-lead electrocardiogram at 4 weeks; main secondary outcomes are adverse events, total medical and societal costs, quality of life, and cost-effectiveness for 1 year.

CONCLUSIONS

The ACWAS trial aims at providing evidence for the use of a wait-and-see approach for patients with recent-onset symptomatic AF in the emergency department.

Factor XIa and Thrombin Generation Are Elevated in Patients with Acute Coronary Syndrome and Predict Recurrent Cardiovascular Events

Objective

In acute coronary syndrome (ACS) cardiac cell damage is preceded by thrombosis. Therefore, plasma coagulation markers may have additional diagnostic relevance in ACS. By using novel coagulation assays this study aims to gain more insight into the relationship between the coagulation system and ACS.

Methods

We measured plasma thrombin generation, factor XIa and D-dimer levels in plasma from ACS (n = 104) and non-ACS patients (n = 42). Follow-up measurements (n = 73) were performed at 1 and 6 months. Associations between coagulation markers and recurrent cardiovascular events were calculated by logistic regression analysis.

Results

Thrombin generation was significantly enhanced in ACS compared to non-ACS patients: peak height 148±53 vs. 122±42 nM. There was a significantly diminished ETP reduction (32 vs. 41%) and increased intrinsic coagulation activation (25 vs. 7%) in ACS compared to non-ACS patients. Furthermore, compared to non-ACS patients factor XIa and D-dimer levels were significantly elevated in ACS patients: 1.9±1.1 vs. 1.4±0.7 pM and 495(310–885) vs. 380(235–540) μg/L. Within the ACS spectrum, ST-elevated myocardial infarction patients had the highest prothrombotic profile. During the acute event, thrombin generation was significantly increased compared to 1 and 6 months afterwards: peak height 145±52 vs. 100±44 vs. 98±33 nM. Both peak height and factor XIa levels on admission predicted recurrent cardiovascular events (OR: 4.9 [95%CI 1.2–20.9] and 4.5 [1.1–18.9]).

Conclusion

ACS patients had an enhanced prothrombotic profile, demonstrated by an increased thrombin generation potential, factor XIa and D-dimer levels. This study is the first to demonstrate the positive association between factor XIa, thrombin generation and recurrent cardiovascular events.

Identification of Rotors during Human Atrial Fibrillation Using Contact Mapping and Phase Singularity Detection: Technical Considerations

OBJECTIVE

To explore technical challenges of phase singularity (PS) mapping during atrial fibrillation (AF) using direct contact electrograms.

METHODS

AF mapping was performed in high-density epicardial recordings of human paroxysmal (PAF) or persistent (PersAF) (N = 20 pts) AF with an array of 16 × 16 electrodes placed on atrial epicardium. PS points were detected using subsets of electrodes forming rings of varying sizes.

RESULTS

PS detection using a 2 × 2 electrode ring identified 0.88 ± 1.00 PS/s in PAF group and 3.91 ± 2.51 per s in PersAF group (p < 0.001) in 2.4 × 2.4 cm mapping area. All detected PS had a short lifespan with the longest being 1100 ms (6.8 rotations). Exploration of the PS detection in a numerical model demonstrated that at least eight electrodes are required to avoid frequent false positive PS detection due to chance. Application of a detection grid consisting a double ring of electrodes (2 × 2 and 4 × 4 rings) decreased the number of false positive detections. The double ring was more resilient to electrode swapping (with just three instances of false positives versus 4380 false positives using 2 × 2 ring).

CONCLUSIONS

The number of detected rotors critically depends upon the parameters of the detection algorithm, especially the number of electrodes used to detect PS. Based on our results, we recommend double ring comprised of 2 × 2 and 4 × 4 grid of electrodes for robust rotor detection.

SIGNIFICANCE

Great methodological care has to be taken before equating detected PS with rotating waves and using PS detection algorithms to guide catheter ablation of AF.

Gradual increase in thrombogenicity of juvenile platelets formed upon offset of prasugrel medication

In patients with acute coronary syndrome, dual antiplatelet therapy with aspirin and a P2Y12 inhibitor like prasugrel is prescribed for one year. Here, we investigated how the hemostatic function of platelets recovers after discontinuation of prasugrel treatment. Therefore, 16 patients who suffered from ST-elevation myocardial infarction were investigated. Patients were treated with aspirin (100 mg/day, long-term) and stopped taking prasugrel (10 mg/day) after one year. Blood was collected at the last day of prasugrel intake and at 1, 2, 5, 12 and 30 days later. Platelet function in response to ADP was normalized between five and 30 days after treatment cessation and in vitro addition of the reversible P2Y12 receptor antagonist ticagrelor fully suppressed the regained activation response. Discontinuation of prasugrel resulted in the formation of an emerging subpopulation of ADP-responsive platelets, exhibiting high expression of active integrin αIIbβ3. Two different mRNA probes, thiazole orange and the novel 5'Cy5-oligo-dT probe revealed that this subpopulation consisted of juvenile platelets, which progressively contributed to platelet aggregation and thrombus formation under flow. During offset, juvenile platelets were overall more reactive than older platelets. Interestingly, the responsiveness of both juvenile and older platelets increased in time, pointing towards a residual inhibitory effect of prasugrel on the megakaryocyte level. In conclusion, the gradual increase in thrombogenicity after cessation of prasugrel treatment is due to the increased activity of juvenile platelets.

Left ventricular three-dimensional quadripolar lead acute clinical study: the LILAC study

AIMS

This multicenter acute clinical study was designed to verify novel three-dimensional (3D) quadripolar lead designs that can achieve ≤2.5 V average pacing capture threshold (PCT) not only at the apex, but also at the base of the left ventricle with phrenic nerve stimulation (PNS) avoidance for cardiac resynchronization.

METHODS

During the implant procedure, up to two different left ventricular investigational leads were introduced and tested in the same target coronary vein based on the coronary sinus venogram in a wedged and unwedged position. Adverse events were collected in 30 days following the procedure.

RESULTS

Eighty-seven leads were tested in 50 patients. When the best performing spiral electrode was chosen from each lead testing, the average of the best PCT on spiral in a wedged position was similar to the unwedged position (1.7 ± 1.5 V vs 1.9 ± 1.5 V, P = ns) and was similar to the wedged tip electrode average PCT (1.7 ± 1.5 V vs 1.6 ± 1.6 V, P = ns). In the majority of patients (89-96%), pacing was achievable in a mid-basal ventricular location without PNS.

CONCLUSIONS

This acute study demonstrated that a 3D quadripolar spiral lead design can achieve acceptable PCTs and avoid PNS without repositioning the lead at implant in the vast majority of patients. It also demonstrated that this lead design can achieve mid-basal ventricular stimulation with low PCT and good acute stability.

Management Of Pulmonary Vein Stenosis Following Catheter Ablation Of Atrial Fibrillation

There is limited literature available regarding PV (pulmonary vein) stenosis management. Starting from its incidence, subsequent follow up using imaging technologies to monitor the success and the way of managing different groups pose varied opinions. However, with newer technological advancements and better understanding of mechanism of the atrial fibrillation ablation, the incidence of PV stenosis secondary to catheter ablation is declining. This paper highlights the current trends and future of management of PV stenosis secondary to catheter ablation for atrial fibrillation.

Effects of dronedarone started rapidly after amiodarone discontinuation

BACKGROUND

Multiple studies have shown that amiodarone is effective in treating atrial fibrillation (AF), but is associated with a relatively high incidence of side effects; however, due to amiodarone's long elimination half-life (20-100 days), physicians may hesitate to start other drugs until it has fully cleared.

HYPOTHESIS

A rapid switch from amiodarone to dronedarone is feasible.

METHODS

EURIDIS and ADONIS were double-blind, multinational, parallel-group trials comparing the efficacy and safety of dronedarone with placebo over 12 months. This retrospective subanalysis of EURIDIS/ADONIS compared the effects of dronedarone in patients discontinuing amiodarone within 2 days before randomization ("rapid switch") with results in patients who had received no amiodarone during the 2 months preceding randomization.

RESULTS

In total, 1237 patients were enrolled ("rapid switch", n = 154; "no amiodarone", n = 1014). In both the "rapid switch" and the "no amiodarone" groups, dronedarone users had significantly lower AF recurrence than patients receiving placebo (HR = 0.64, 95% CI, 0.44-0.95; P = 0.0224 and HR = 0.79, 95% CI, 0.67-0.92; P = 0.0027, respectively). Dronedarone users had a higher incidence of bradyarrhythmic events than placebo-treated patients. A "rapid switch" from amiodarone to dronedarone was associated with a higher incidence of serious heart failure events and heart failure hospitalizations versus all other groups. Overall event rates were low and there was no significant difference in total adverse event rates or deaths between groups.

CONCLUSION

In this patient population, a switch from amiodarone to dronedarone within a 2-day time frame might be feasible in certain patient categories, but further investigation is warranted.

Tailored Telemonitoring in patients with heart failure: results from a multicentre randomized controlled trial (the TEHAF-study)

Background

Recent increasing prevalence of heart failure (HF) patients leads to an increasing burden to the health care system. Consequently, there is a need for innovative strategies to reduce HF hospitalizations.

Methods

We performed a multicentre randomized controlled trial to test the hypothesis that telemonitoring in patients with HF, by means of the Health Buddy^® system (HB), will reduce HF hospitalizations and number of contacts with caregivers as compared to care as usual (CAU) during 1 year follow-up, from October 1, 2007, through December 31, 2008.

Results

Among 382 patients—197 in the HB and 185 in the CAU-group—226 (59%) were male, mean age was 71.5 (SD 11.2), 45.5% being ≥75 years of age; 57% of the patients were in NYHA HF class 2, 40% in class 3 and 3% in class 4. Both study groups were similar for demographic and clinical characteristics. Mean time to first heart failure related hospitalization was 161 days for the intervention group and 139 days for the usual-care group; hospitalizations occurred in 18 (9.1%) compared to 25 patients (13.5%) respectively (Kaplan–Meier p=0.151, hazard ratio 0.65, CI 0.35–1.17). Combined endpoint of heart failure admission and all cause mortality was similar for both groups (Kaplan–Meier p=0.641 hazard ratio 0.89, CI 0.69–1.83). Cox regression analysis disclosed an important interaction between group assignment and heart failure duration, p=0.007, OR=0.983, CI 0.970–0.995 indicating a significant decrease in heart failure hospitalizations in the intervention group if heart failure duration was <18 months, p=0.026, hazard ratio 0.26, CI 0.07–0.94. Contacts with the heart-failure-nurse were mean 1.36 (range 0–11) in the intervention group vs. 1.74 (0–8) in the usual-care group (Mann-Whitney p<0.001). Mortality was 18 (9.1%) in the intervention-group and 12 (6.5%) in the usual-care-group (Mann–Whitney p=0.34, Cox-regression analysis p=0.82).

Conclusion

Telemonitoring tends to reduce heart failure admissions and decreases contacts with specialized nurses. If heart failure duration is <18 months heart failure admissions and readmissions are significantly reduced.

Celivarone for maintenance of sinus rhythm and conversion of atrial fibrillation/flutter

INTRODUCTION

Celivarone, a new noniodinated benzofuran derivative pharmacologically related to dronedarone and amiodarone, has been shown to have antiarrhythmic properties at a molecular level. The purpose of the 2 trials presented here (MAIA and CORYFEE) was to assess celivarone efficacy in the maintenance of sinus rhythm postcardioversion and for the conversion of atrial fibrillation (AF)/atrial flutter (AFL).

METHODS AND RESULTS

In the MAIA trial, 673 patients with AF/AFL recently converted to sinus rhythm were randomly assigned to receive 50, 100, 200, or 300 mg once-daily dosing of celivarone; 200 mg daily of amiodarone preceded by a loading dose of 600 mg for 10 days; or placebo. At 3 months' follow up, no significant difference was observed in time to AF/AFL relapse among the various celivarone groups and placebo. However, fewer symptomatic AF/AFL recurrences were observed in the lower-dose celivarone groups (26.6% for celivarone 50 mg [P = 0.022] and 25.2% for celivarone 100 mg [P = 0.018] vs 40.5% for placebo at 90 days). Fewer adverse events were observed with the use of celivarone and placebo than amiodarone. In the CORYFEE study, 150 patients with AF/AFL were randomly assigned to once-daily celivarone dosing of 300 or 600 mg, or placebo, for a 2-day treatment period. There was no significant difference in the rate of spontaneous conversion to sinus rhythm between the treatment and control groups.

CONCLUSIONS

In these studies, celivarone does not appear to be efficacious in the maintenance of sinus rhythm in AF/AFL patients or for the conversion of AF/AFL patients. 

Physician stated atrial fibrillation management in light of treatment guidelines: data from an international, observational prospective survey

BACKGROUND

The Registry on Cardiac Rhythm Disorders Assessing the Control of Atrial Fibrillation (RecordAF) study is the first worldwide, prospective, survey of real-life management of atrial fibrillation (AF) in recently diagnosed patients (n = 5604) with a 1-year follow-up.

HYPOTHESIS

Surveys of AF management have identified a divergence between guidelines and clinical practice, and an overinterpretation of guidelines in low-risk patients.

METHODS

: Physicians' theoretical approaches to rhythm and rate control were investigated using a pre-study questionnaire.

RESULTS

One cardiologist, from each of the 583 sites in 6 regions, completed a questionnaire on their practice and management of AF patients. In AF patients with structural heart disease (SHD), amiodarone was the most frequent choice of first-line rhythm control agents in all regions. Amiodarone or sotalol tended to be the preferred second-line rhythm control agents, 1 exception being Central/South America. beta-Blockers were the first-line rate control agents for patients with AF and SHD in all regions, and calcium channel blockers and cardiac glycosides were the most common second-line rate control treatments in all regions, except Asia. In lone AF patients, propafenone (30.6%), flecainide (24.1%), and amiodarone (21.7%) were the most common global choices of first-line rhythm control, and amiodarone or sotalol were the preferred second-line rhythm control agents, 1 exception being Central/South America.

CONCLUSIONS

These results highlight points of divergence from the American College of Cardiology (ACC)/ American Heart Association (AHA)/European Society of Cardiology (ESC) guidelines for the management of AF in terms of first-line drug selection in patients with associated SHD or coronary artery disease.

Electropathological Substrate of Longstanding Persistent Atrial Fibrillation in Patients With Structural Heart Disease

Background—

During persistent atrial fibrillation (AF), waves with a focal spread of activation are frequently observed. The origin of these waves and their relevance for the persistence of AF are unknown.

Methods and Results—

In 24 patients with longstanding persistent AF and structural heart disease, high-density mapping of the right and left atria was performed during cardiac surgery. In a reference group of 25 patients, AF was induced by rapid pacing. For data analysis, a mapping algorithm was developed that separated the fibrillatory process into its individual wavelets and identified waves with a focal origin. During persistent AF, the incidence of focal fibrillation waves in the right atrium was almost 4-fold higher than during acute AF (median, 0.46 versus 0.12 per cycle per 1 cm 2 (25th to 75th percentile, 0.40 to 0.77 and 0.01 to 0.27; P <0.0001). They were widely distributed over both atria and were recorded at 46±18 of all electrodes. A large majority (90.5) occurred as single events. Repetitive focal activity (>3) happened in only 0.8. The coupling interval was not more than 11 ms shorter than the average AF cycle length ( P =0.04), and they were not preceded by a long interval. Unipolar electrograms at the site of origin showed small but clear R waves. These data favor epicardial breakthrough rather than a cellular focal mechanism as the underlying mechanism. Often, conduction from a site of epicardial breakthrough was blocked in 1 or more directions. This generated separate multiple wave fronts propagating in different directions over the epicardium.

Conclusions—

Focal fibrillation waves are due to epicardial breakthrough of waves propagating in deeper layers of the atrial wall. In patients with longstanding AF, the frequency of epicardial breakthroughs was 4 times higher than during acute AF. Because they provide a constant source of independent fibrillation waves originating over the entire epicardial surface, they offer an adequate explanation for the high persistence of AF in patients with structural heart disease.

Prevention of stroke in patients with atrial fibrillation: the role of new antiarrhythmic and antithrombotic drugs

BACKGROUND

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It is associated with increased cardiovascular mortality and morbidity, including stroke.

RESULTS

Rate or rhythm control and prevention of thromboembolism with oral anticoagulants are the main management objectives for patients with AF. Until recently, rhythm control studies did not show prevention of cardiovascular complications. However, dronedarone, a novel antiarrhythmic drug, has been shown to decrease stroke risk by 34% (p = 0.027). In addition, the Randomized Evaluation of Long-Term Anticoagulant Therapy trial showed significant stroke reductions with the anticoagulant dabigatran 150 mg b.i.d. compared with adjusted-dose warfarin (the results for dabigatran 110 mg b.i.d. were similar to warfarin).

CONCLUSIONS

Novel antithrombotic agents and antiarrhythmic agents with cardiovascular prophylactic properties may enhance the management of stroke risk in patients with AF.

The impact of new and emerging clinical data on treatment strategies for atrial fibrillation

INTRODUCTION

The Atrial Fibrillation (AF) Exchange Group, an international multidisciplinary group concerned with the management of AF, was convened to review recent advances in the field and the potential impact on treatment strategies.

METHODS

Issues discussed included epidemiology and the impact of the rising incidence of AF on health care systems, developments in pharmacological and surgical interventions in the management of arrhythmias and thromboprophylaxis, the potential to affect treatment strategies, and barriers to implementing them.

RESULTS

The incidence of AF and the associated burden on health care systems are increasing with aging populations, prevalence of comorbidities and more effective treatment of cardiovascular diseases. Advances in available medical treatments, in particular dronedarone and dabigatran, with other products in development, offer the possibility of changes in treatment paradigms and a greater emphasis on reducing hospitalizations and improvement in long-term outcomes instead of a symptom/safety-driven approach in which the priority is symptom suppression without provoking drug toxicity. Developments in catheter ablation techniques may mean that, in experienced centers, ablation may be offered as first-line treatment in selected patient populations. Barriers to optimal treatment include underdiagnosis, lack of recognition as a serious condition and as a risk factor for stroke, limited access to care, inadequate implementation of guidelines, and poor adherence to treatment.

CONCLUSIONS

The focus of the management of AF may be changing as a consequence of new treatments based on the outcome improvements they offer. However, the benefits will not be fully realized if guidelines and guidance are not observed in routine clinical practice.

The symptomatology of post-stroke depression: comparison of stroke and myocardial infarction patients

BACKGROUND

Depression is a frequent problem in stroke patients but, all too often, the problem goes unrecognized. How depression-like symptoms in post-stroke depression (PSD) should be interpreted is still subject to debate. If PSD has a distinct symptom profile of depression accompanying other chronic vascular somatic conditions then this could imply that PSD is a specific disease entity.

OBJECTIVE

To study whether depressed stroke patients exhibit other signs and symptoms than patients suffering from depression after myocardial infarction (MI).

METHODS

Depressive signs and symptoms were measured using the Hospital Anxiety and Depression Scale and the 17-item Hamilton Depression Rating Scale. The results of 190 stroke patients were compared with the results of 198 MI patients every 3 months during the first year after the event.

RESULTS

Depressed stroke patients exhibited more loss of interest, psychomotor retardation, and gastro-intestinal complaints as compared to depressed MI patients. However, in multivariate analyses including both depressed and non-depressed stroke and MI patients, no specific symptom profile was found to differentiate between the two depressive syndromes by looking at the modifying effect of stroke vs MI on the occurrence of specific symptoms in depression.

CONCLUSION

Although in their clinical presentation, depressed stroke patients exhibit a symptom profile different from depressed MI patients, this is not due to differences in the depressive syndrome in these two patient groups but it reflects differences between stroke and MI patients in general.