When is Device-Detected Atrial Fibrillation Actionable?

Device-detected atrial high-rate episodes (AHREs) are frequently encountered in patients with no history of atrial fibrillation (AF) and represent a challenge for clinicians because patients with device-only documented AF have not been included in clinical trials of anticoagulants and other AF therapies. For patients with known history of AF, wireless continuous rhythm monitoring and rapidly acting oral anticoagulants offer the possibility of tailored anticoagulation in response to AHREs, with studies ongoing to evaluate the safety of this approach. This article provides an overview of current evidence on device-detected AHREs and evolving areas of investigation.

Does the CHA2DS2-VASc score reliably predict atrial arrhythmias? Analysis of a nationwide database of remote monitoring data transmitted daily from cardiac implantable electronic devices

BACKGROUND

CHA₂DS₂-VASc is a validated score for predicting stroke in patients with atrial fibrillation (AF).

OBJECTIVE

The purpose of this study was to assess whether the CHA₂DS₂-VASc score can predict new-onset AF in a cohort of patients with a cardiac implantable electronic device (CIED) followed with remote monitoring.

METHODS

Using the database of the Home Monitoring Expert Alliance project, we selected 2410 patients with no documented AF who had received a CIED with diagnostics on atrial high rate episodes (AHREs). The primary endpoint was time to first day with cumulative AHRE burden ≥15 minutes, 5 hours, 24 hours, and ≥7 consecutive days.

RESULTS

During a median duration of 24.1(11.5-42.9) months, the incidence of AHRE increased with increasing CHA₂DS₂-VASc. At 6 years, occurrence of ≥15-minute AHRE was 80.2% (CHA₂DS₂-VASc ≤1) vs 93.7% (CHA₂DS₂-VASc ≥5), whereas ≥5-hour AHRE incidence was 68.4% (CHA₂DS₂-VASc ≤1) vs 92.5% (CHA₂DS₂-VASc ≥5). Occurrence of ≥24-hour and ≥7-day AHREs also increased with increasing CHA₂DS₂-VASc: 9.1% and 3.9% (CHA₂DS₂-VASc ≤1) vs 40.4% and 28.7% (CHA₂DS₂-VASc ≥5), respectively. Adjusted hazard ratio for unitary CHA₂DS₂-VASc increase ranged from 1.09 (confidence interval 1.04-1.14; P <.001) with AHRE burden ≥15 minutes to 1.26 (confidence interval 1.11-1.42; P <.001) with AHRE burden ≥7 days. At receiver operating curve analysis, CHA₂DS₂-VASc ≥2 was estimated to predict persistent forms of AHREs with 95.8% sensitivity but 11.7% specificity at 3 years. CHA₂DS₂-VASc ≥5 had 77.0% specificity but 34.6% sensitivity.

CONCLUSION

In a CIED population with no previous diagnosis of clinical AF, AHRE incidence increased with increasing CHA₂DS₂-VASc score. The association was stronger with longer AHREs, but the accuracy of CHA₂DS₂-VASc as AHRE predictor was moderate.

Physician decision making in anticoagulating atrial fibrillation: a prospective survey of a physician notification system for atrial fibrillation detected on cardiac implantable electronic devices of patients at increased risk of stroke

OBJECTIVES

The objectives of this study were to evaluate the effectiveness of a physician notification system for atrial fibrillation (AF) detected on cardiac devices, and to assess predictors of anticoagulation in patients with device-detected AF.

METHODS

In 2013, a physician notification system for AF detected on a patient's CIED [including pacemakers, implantable cardioverter defibrillators (ICD) or cardiac resynchronization therapy (CRT) devices] was implemented, with a recommendation to consider oral anticoagulation in high-risk patients. We prospectively investigated the effectiveness of this system, and evaluated both patient and physician predictors of anticoagulation, as well as factors influencing physician decision making in prescribing anticoagulation. Both uni- and multivariable analysis as well as descriptive statistics were used in the analysis.

RESULTS

We identified 177 patients with device-detected AF, 126 with a CHADS2 ⩾2. Only 41% were prescribed anticoagulation at any point within 12 months. On multivariable analysis, stroke risk as predicted by CHADS2 was not a predictor of anticoagulation. ASA use predicted a lower rate of anticoagulation (OR 0.39, 95% CI 0.16-0.97, p = 0.04); physicians in practice for <20 years were more likely to prescribe anticoagulation (OR 3.39, 95% CI 1.28-8.93, p = 0.01); and physicians who believed both cardiologist and family doctor should be involved in managing anticoagulation were more likely to prescribe anticoagulation (OR 3.28, 95% CI 1.02-10.5, p = 0.05).

CONCLUSIONS

Patients on aspirin were less likely to be anticoagulated. Physicians in practice for <20 years and who believed that both the general practitioner and cardiologist should be involved in managing anticoagulants were more likely to prescribe anticoagulation.

Stroke risk in patients with device-detected atrial high-rate episodes

Cardiovascular implantable electronic devices (CIEDs) can detect atrial arrhythmias, i. e. atrial high-rate episodes (AHRE). The thrombo-embolic risk in patients showing AHRE appears to be lower than in patients with clinical atrial fibrillation (AF) and it is unclear whether the former will benefit from oral anticoagulants. Based on currently available evidence, it seems reasonable to consider antithrombotic therapy in patients without documented AF showing AHRE >24 hours and a CHA₂DS₂-VASc score (congestive heart failure, hypertension, age ≥75 years [doubled], diabetes mellitus, prior stroke [doubled], vascular disease, age 65-74 years and female sex) ≥1, awaiting definite answers from ongoing randomised clinical trials. In patients with AHRE <24 hours, current literature does not support starting oral anticoagulation. In these patients, intensifying CIED read-outs can be considered to find progression in AHRE duration sooner, enhancing timely stroke prevention. The notion that AHRE and stroke coincide perseveres but should be abandoned since CIED data show a clear disconnect.

[Device-based remote monitoring : Current evidence]

Telemedicine is increasingly used in clinical cardiology. It offers early detection of arrhythmias, technical device follow-up and support of heart failure management. Regarding technical device follow-up, remote monitoring significantly reduces usage of the health care system. Furthermore, remote monitoring is associated with a significantly reduced time from device malfunction to physician's perception of the event. Using remote monitoring, inappropriate ICD (implantable cardioverter defibrillator) shocks can be significantly reduced compared to routine in-office follow-up. In retrospective studies and meta-analyses a prognostic benefit with respect to mortality has been shown. Device-based detection of atrial fibrillation and atrial high rate episodes is feasible. However, clinical relevance is currently studied in prospective randomized clinical trials. Heart failure management based on surrogate parameters has not been shown to significantly improve outcome. However, therapeutic management based on pulmonary artery pressure has been shown to significantly reduce morbidity and mortality. This review offers a comprehensive overview on the role of remote monitoring in heart failure management, technical device follow-up and detection of atrial fibrillation and atrial high rate episodes.

Probing oral anticoagulation in patients with atrial high rate episodes: Rationale and design of the Non-vitamin K antagonist Oral anticoagulants in patients with Atrial High rate episodes (NOAH-AFNET 6) trial

Oral anticoagulation prevents ischemic strokes in patients with atrial fibrillation (AF). Early detection of AF and subsequent initiation of oral anticoagulation help to prevent strokes in AF patients. Implanted cardiac pacemakers and defibrillators allow seamless detection of atrial high rate episodes (AHRE), but the best antithrombotic therapy in patients with AHRE is not known.

Rationale

Stroke risk is higher in pacemaker patients with AHRE than in those without, but the available data also show that stroke risk in patients with AHRE is lower than in patients with AF. Furthermore, only a minority of patients with AHRE will develop AF, many strokes occur without a temporal relation to AHRE, and AHRE can reflect other arrhythmias than AF or artifacts. An adequately powered controlled trial of oral anticoagulation in patients with AHRE is needed.

Design

The Non–vitamin K antagonist Oral anticoagulants in patients with Atrial High rate episodes (NOAH–AFNET 6 ) trial tests whether oral anticoagulation with edoxaban is superior to prevent the primary efficacy outcome of stroke or cardiovascular death compared with aspirin or no antithrombotic therapy based on evidence-based indications. The primary safety outcome will be major bleeding. NOAH–AFNET 6 will randomize 3,400 patients with AHRE, but without documented AF, aged ≥65 years with at least 1 other stroke risk factor, to oral anticoagulation therapy (edoxaban) or no anticoagulation. All patients will be followed until the end of this investigator-driven, prospective, parallel-group, randomized, event-driven, double-blind, multicenter phase IIIb trial. Patients will be censored when they develop AF and offered open-label anticoagulation. The sponsor is the Atrial Fibrillation NETwork (AFNET). The trial is supported by the DZHK (German Centre for Cardiovascular Research), the BMBF (German Ministry of Education and Research), and Daiichi Sankyo Europe.

Conclusion

NOAH–AFNET 6 will provide robust information on the effect of oral anticoagulation in patients with atrial high rate episodes detected by implanted devices.

Rationale and design of the Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation (ARTESiA) trial

BACKGROUND

Device-detected subclinical atrial fibrillation (AF) refers to infrequent, short-lasting, asymptomatic AF that is detected only with long-term continuous monitoring. Subclinical AF is common and associated with an increased risk of stroke; however, the risk of stroke with subclinical AF is lower than for clinical AF, and very few patients with subclinical AF alone have been included in large AF anticoagulation trials. The net benefit of anticoagulation in patients with subclinical AF is unknown.

DESIGN

ARTESiA is a prospective, multicenter, double-blind, randomized controlled trial, recruiting patients with subclinical AF detected by an implanted pacemaker, defibrillator, or cardiac monitor, and who have additional risk factors for stroke. Patients with clinical AF documented by surface electrocardiogram will be excluded from the study. Participants will be randomized to receive either apixaban (according to standard AF dosing) or aspirin 81mg daily. The primary outcome is the composite of stroke, transient ischemic attack with diffusion-weighted magnetic resonance imaging evidence of cerebral infarction, and systemic embolism. Approximately 4,000 patients will be enrolled from around 230 clinical sites, with an anticipated mean follow-up of 36months until 248 adjudicated primary outcome events have occurred.

SUMMARY

ARTESiA will determine whether oral anticoagulation therapy with apixaban compared with aspirin reduces the risk of stroke or systemic embolism in patients with subclinical AF and additional risk factors.

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.

Stroke Prevention for Patients with Atrial Fibrillation: Beyond the Guidelines

Atrial fibrillation (AF) is the most common serious heart rhythm disorder, with a lifetime incidence of 1 in 4 for patients >40 years of age[1]. AF is a major cause of death and disability, as it is associated with a 4-5 fold increase in the risk of ischemic stroke[2]. In patients with AF, oral anticoagulation (OAC) therapy can reduce the risk of stroke by about two-thirds and the risk of all-cause mortality by approximately one-quarter, but is associated with an increased risk of bleeding[3], [4]. Atrial fibrillation (AF) is the most common serious heart rhythm disorder and is associated with an increased risk of ischemic stroke. This risk can be moderated with oral anticoagulation therapy, but the decision to do so must be balanced against the risks of bleeding. Herein, we discuss three emerging areas where more high-quality evidence is required to guide risk stratification: 1) the relationships between the pattern and burden of AF and stroke 2) the risk conferred by short episodes of device-detected "sub-clinical" atrial fibrillation (SCAF) and 3) the significance of AF that occurs transiently with stress (AFOTS), as is often detected during medical illness or after surgery. Risk stratification is important to identify patients with AF who can benefit from OAC therapy. There are, however, several common clinical scenarios where guidelines do not yet provide direction for stroke prevention; or do so based on limited high-quality evidence.

Early Detection and Treatment of Atrial Arrhythmias Alleviates the Arrhythmic Burden in Paced Patients: The SETAM Study

BACKGROUND

Remote monitoring (RM) can remotely detect atrial tachyarrhythmias (ATAs). The benefit of RM compared to conventional follow-up in the detection and management of ATA was assessed in recipients of dual-chamber pacemakers.

METHODS

The multicenter randomized SETAM study enrolled 595 patients in sinus rhythm with a CHA₂ DS₂ -VASc score ≥2, without ATA history and untreated with antiarrhythmics and antithrombotics, randomly assigned to RM (RM-ON; n = 291) versus ambulatory follow-up (RM-OFF; n = 304) during 12.8 ± 3.3 months. ATA occurrence, burden, and management were analyzed together with adverse clinical events.

RESULTS

Patients were 79 ± 8 years old, 63% men, with a CHA₂ DS₂ -VASc score of 3.7± 1.2. ATA were detected in 83 patients (28%) in the RM-ON versus 66 (22%) in the RM-OFF group (P = 0.06). The median time between the pacemaker implantation and the first treated ATA was 114 days [44; 241] in the RM-ON versus 224 days [67; 366] in the RM-OFF group (hazard ratio [HR] = 0.56; 95% confidence interval [CI]: 0.37-0.86; P = 0.01). Therapies for ATA were initiated in 92 patients and the time to treatment of ATA was shortened by 44% in the RM-ON group (HR = 0.565; 95% CI: 0.37-0.86; P = 0.01). Over the last 4 months of follow-up, the mean ATA burden was alleviated by 4 hours/day (18%) in the RM-ON group. The rate of adverse clinical events was similar in both groups.

CONCLUSION

Remotely monitored patients were diagnosed and treated earlier for ATA, and subsequently had a lower ATA burden.

Atrial high-rate episodes and stroke prevention

While the benefit of oral anticoagulants (OACs) for stroke prevention in patients with atrial fibrillation (AF) is well established, it is not known whether oral anticoagulation is indicated in patients with atrial high-rate episodes (AHRE) recorded on a cardiac implantable electronic device, sometimes also called subclinical AF, and lasting for at least 6 min in the absence of clinically diagnosed AF. Clinical evidence has shown that short episodes of rapid atrial tachycarrhythmias are often detected in patients presenting with stroke and transient ischaemic attack. Patients with AHRE have a higher likelihood of suffering from subsequent strokes, but their stroke rate seems lower than in patients with diagnosed AF, and not all AHRE episodes correspond to AF. The prognostic and pathological significance of AHRE is not yet fully understood. Clinical trials of OAC therapy are being conducted to determine whether therapeutic intervention would be beneficial to patients experiencing AHRE in terms of reducing the risk of stroke.

Anticoagulation in patients at high risk of stroke without documented atrial fibrillation. Time for a paradigm shift?

Atrial fibrillation (AF) is currently considered a risk factor for stroke. Depending on the severity of clinical factors (risk scores) a recommendation for full anticoagulation is made. Although AF is most certainly a risk factor for ischemic stroke, it is not necessarily the direct cause of it. The causality of association between AF and ischemic stroke is questioned by the reported lack of temporal relation between stroke events and AF paroxysms (or atrial high-rate episodes detected by devices). In different studies, only 2% of patients had subclinical AF > 6 minutes in duration at the time of stroke or systemic embolism. Is it time to consider AF only one more factor of endothelial disarray rather than the main contributor to stroke? In this "opinion paper" we propose to consider not only clinical variables predicting AF/stroke but also electrocardiographic markers of atrial fibrosis, as we postulate this as a strong indicator of risk of AF/stroke. We ask if it is time to change the paradigm and to consider, in some special situations, to protect patients (preventing stroke) who have no evidence of AF.

Determinants of Time in Therapeutic Range in Patients Receiving Oral Anticoagulants (A Substudy of IMPACT)

Implanted cardiac arrhythmia devices can detect atrial tachyarrhythmias (atrial high-rate episodes [AHREs]) that are considered to correlate with atrial fibrillation and risk of stroke. In the IMPACT trial, oral anticoagulation was initiated when AHREs were detected by implanted cardioverter-defibrillators and withdrawn when they abated, according to a protocol accounting both for AHRE duration as detected by remote device monitoring and stroke risk assessment. In this analysis, we ascertained determinants of time in therapeutic range (TTR) among protocol-determined vitamin K antagonist-treated patients during the trial. We enrolled 2,718 patients with at least 1 additional stroke risk factor (CHADS₂ score ≥1) at 104 arrhythmia centers. The sex, age <60, medical history, treatments interacting with VKA, tobacco use (2 points) and race (2 points for non-Caucasian) (SAMe-TT₂R₂) score is a simple clinical-derived score designed to aid decision-making on whether a patient is likely to achieve good anticoagulation control on vitamin K antagonist (e.g., warfarin), which was calculated and related to TTR achieved using the Rosendaal method. We analyzed 229 patients (mean age 66.7 years; mean CHADS₂ score 2.85 [SD 1.1]) with mean TTR of 0.536 (SD 0.23) overall. Univariate analysis identified 5 variables associated with differences in mean TTR. Mean TTR was lower in those who were women (p = 0.031), of black race (p = 0.005) and in New York Heart Association class IV (p = 0.014), whereas hemoglobin >13.5 g/dl (p = 0.010) and New York Heart Association class I (p = 0.037) were associated with higher mean TTR. There was a significant difference in mean TTR value between US and non-US sites (Canada and Germany) (mean TTR for US: 0.513 vs non-US: 0.686; p <0.0001). Mean TTR was significantly lower (Δ = 0.1382, 95% CI 0.0382 to 0.2382) for patients with SAMe-TT₂R₂ scores of 4 (p = 0.007) and higher (Δ = 0.0612, 95% CI 0.0005 to 0.1219) for patients with SAMe-TT₂R₂ scores of 1 (p = 0.048). Linear regression confirmed a significant association between lower SAMe-TT₂R₂ score and improved anticoagulation control (p = 0.0021) with a 1-unit decrease in SAMe-TT₂R₂ score associated with an increase in TTR of 0.0404 (95% CI 0.0149 to 0.0659). In conclusion, clinical, geographical, and demographic factors were associated with the quality of anticoagulation control as reflected by TTR. Although overall TTR in this population was poor, lower SAMe-TT₂R₂ scores were associated with better TTR.

Electrocardiographic and Echocardiographic predictors of paroxysmal atrial fibrillation detected after ischemic stroke

BACKGROUND

Detection of atrial fibrillation after ischemic stroke is challenging due to its paroxysmal nature. We aimed to assess predictors of paroxysmal atrial fibrillation using non-invasive surface ECG and transthoracic echocardiography to select candidates for atrial fibrillation screening.

METHODS

Ischemic stroke patients without documented atrial fibrillation (n = 110, 67 ± 10 years, 40 female) and a control group of age- and gender-matched patients with history of paroxysmal atrial fibrillation prior to stroke (n = 55, 67 ± 10 years, 19 female) comprised the study sample. Using non-invasive ECG monitoring for three weeks, short episodes of paroxysmal atrial fibrillation were detected in 24 of 110 patients (22 %). The standard 12-lead ECG with sinus rhythm at stroke onset was digitally processed and analyzed. Transthoracic echocardiography data were reviewed for these patients.

RESULTS

Atrial fibrillation history was independently associated with P terminal force in lead V 1 > 40 mm*ms (OR 4.04 95 % CI 1.34-12.14, p = 0.013) and left atrial volume index (OR 1.08 95 % CI 1.03-1.13, p = 0.002; for LAVI > 40 mL/m² OR 6.40 95 % CL 1.47-27.91, p = 0.013). Among patients without atrial fibrillation history, no ECG characteristics were predictive of atrial fibrillation detected after stroke. Left atrial volume index remained an independent predictor of atrial fibrillation detected after stroke (OR 1.09 95 % CI 1.02-1.16, p = 0.017). A cutoff of <40 mL/m² had an 84 % negative predictive value for ruling out atrial fibrillation on ambulatory monitoring with a sensitivity of 50 % and a specificity of 86 %.

CONCLUSION

In a post hoc analysis, left atrial dilatation assessed by left atrial volume index independently predicted atrial fibrillation after stroke in patients without prior atrial fibrillation history, while the other clinical or ECG markers were not predictive of atrial fibrillation detected early after ischemic stroke.

TRIAL REGISTRATION

This study is a post hoc analysis from the prospective case-control study registered in December 2011, ClinicalTrials.gov ID: NCT01325545 .

Implantable cardioverter defibrillator management: an update

Implantable cardioverter defibrillator (ICD) is the cornerstone of primary and secondary prevention of sudden cardiac death. In 35 years of technologic improvement and clinical trials, there has been a continuous increase in implantation rate. Purpose of this review is to point out and discuss every aspect related to actual ICD management, investigating implantation procedure and predischarge care, office and remote monitoring follow-up, diagnostic evaluations, management of patients with suspected therapies or malfunctions, heart failure, surgery, radiotherapy and endoscopic procedures. Also, ICD backface such as infections and other complications will be discussed. Finally, we will focus on interesting future perspectives for this setting of patients.

Clinical Implications of Brief Device-Detected Atrial Tachyarrhythmias in a Cardiac Rhythm Management Device Population

Background:

The RATE Registry (Registry of Atrial Tachycardia and Atrial Fibrillation Episodes) is a prospective, outcomes-oriented registry designed to document the prevalence of atrial tachycardia and/or fibrillation (AT/AF) of any duration in patients with pacemakers and implantable cardioverter defibrillators (ICDs) and evaluate associations between rigorously adjudicated AT/AF and predefined clinical events, including stroke. The appropriate clinical response to brief episodes of AT/AF remains unclear.

Methods:

Rigorously adjudicated electrogram (EGM) data were correlated with adjudicated clinical events with logistic regression and Cox models. Long episodes of AT/AF were defined as episodes in which the onset and/or offset of AT/AF was not present within a single EGM recording. Short episodes of AT/AF were defined as episodes in which both the onset and offset of AT/AF were present within a single EGM recording.

Results:

We enrolled 5379 patients with pacemakers (N=3141) or ICDs (N=2238) at 225 US sites (median follow-up 22.9 months). There were 359 deaths. There were 478 hospitalizations among 342 patients for clinical events. We adjudicated 37 531 EGMs; 50% of patients had at least one episode of AT/AF. Patients with clinical events were more likely than those without to have long AT/AF (31.9% vs. 22.1% for pacemaker patients and 28.7% vs. 20.2% for ICD patients; P <0.05 for both groups). Only short episodes of AT/AF were documented in 9% of pacemaker patients and 16% of ICD patients. Patients with clinical events were no more likely than those without to have short AT/AF (5.1% vs. 7.9% for pacemaker patients and 11.5% vs. 10.4% for ICD patients; P =0.21 and 0.66, respectively).

Conclusions:

In the RATE Registry, rigorously adjudicated short episodes of AT/AF, as defined, were not associated with increased risk of clinical events compared with patients without documented AT/AF.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00837798.

Cost Effectiveness of Implantable Cardiac Monitor-Guided Intermittent Anticoagulation for Atrial Fibrillation: An Analysis of the REACT.COM Pilot Study

INTRODUCTION

Anticoagulation guidelines for patients with atrial fibrillation (AF) disregard AF burden. A strategy of targeted anticoagulation with novel oral anticoagulants (NOACs) based on continuous rhythm assessment with an implantable cardiac monitor (ICM) has recently been explored. We evaluated the potential cost-effectiveness of this strategy versus projected outcomes with continuous anticoagulation.

METHODS AND RESULTS

We developed a Markov model using data from the Rhythm Evaluation for AntiCoagulaTion With COntinuous Monitoring (REACT.COM) pilot study (N = 59) and prior NOAC trials to calculate the costs and quality-adjusted life years (QALYs) associated with ICM-guided intermittent anticoagulation for AF versus standard care during a 3-year time horizon. Health state utilities were estimated from the pilot study population using the SF-12. Costs were based on current Medicare reimbursement. Over 14 ± 4 months of follow-up, 18 of 59 patients had 35 AF episodes. The ICM-guided strategy resulted in a 94% reduction in anticoagulant use relative to continuous treatment. There were no strokes, 3 (5.1%) TIAs, 2 major bleeding events (on aspirin) and 3 minor bleeding events with the ICM-guided strategy. The projected total 3-year costs were $12,535 for the ICM-guided strategy versus $13,340 for continuous anticoagulation. Projected QALYs were 2.45 for both groups.

CONCLUSION

Based on a pilot study, a strategy of ICM-guided anticoagulation with NOACs may be cost-saving relative to expected outcomes with continuous anticoagulation, with similar quality-adjusted survival. This strategy could be attractive from a health economic perspective if shown to be safe and effective in a rigorous clinical trial.

Intermittent vs. Continuous Anticoagulation theRapy in patiEnts with Atrial Fibrillation (iCARE-AF): a randomized pilot study

PURPOSE

We hypothesized that intermittent anticoagulation based on daily rhythm monitoring using the novel oral anticoagulants (NOACs) is feasible and safe among patients with paroxysmal atrial fibrillation (AF).

METHODS

Patients with paroxysmal AF and ≥1 risk factors for stroke were randomized to either intermittent or continuous anticoagulation. Those in the intermittent group were instructed to transmit a daily ECG using an iPhone-based rhythm monitoring device. If AF was detected, patients received one of the NOACs for 48 h-1 week. Patients who failed to transmit an ECG for three consecutive days or more than 7 days total were crossed over to continuous anticoagulation. Patients in the continuous group received one of the NOACs.

RESULTS

Fifty-eight patients were randomized to either intermittent (n = 29) or continuous anticoagulation (n = 29). Over a median follow-up of 20 months, 20 patients in the intermittent group failed to submit a daily ECG at least once (median three failed submissions). Four patients (14 %) crossed over to continuous anticoagulation due to failure to submit an ECG for three consecutive days. One stroke (continuous group) occurred during the study. Major bleeding occurred in two patients in the continuous and one patient in the intermittent group, after crossing over to continuous anticoagulation. In a prespecified per-protocol analysis, gastrointestinal bleeding was more frequent in the continuous group (16 vs. 0 %; p = 0.047).

CONCLUSIONS

Intermittent anticoagulation based on daily rhythm monitoring is feasible and may decrease bleeding in low-risk patients with paroxysmal AF. A larger trial, adequately powered to detect clinical outcomes, is warranted.

Position paper for management of elderly patients with pacemakers and implantable cardiac defibrillators: Groupe de Rythmologie et Stimulation Cardiaque de la Société Française de Cardiologie and Société Française de Gériatrie et Gérontologie

Despite the increasingly high rate of implantation of pacemakers (PMs) and implantable cardioverter defibrillators (ICDs) in elderly patients, data supporting their clinical and cost-effectiveness in this age stratum are ambiguous and contradictory. We reviewed the data regarding the applicability, safety and effectiveness of conventional pacing, ICDs and cardiac resynchronization therapy (CRT) in elderly patients. Although periprocedural risk may be slightly higher in the elderly, the implantation procedure for PMs and ICDs is still relatively safe in this age group. In older patients with sinus node disease, the general consensus is that DDD pacing with the programming of an algorithm to minimize ventricular pacing is preferred. In very old patients presenting with intermittent or suspected atrioventricular block, VVI pacing may be appropriate. In terms of correcting potentially life-threatening arrhythmias, the effectiveness of ICD therapy is similar in older and younger individuals. However, the assumption of persistent ICD benefit in the elderly population is questionable, as any advantageous effect of the device on arrhythmic death may be attenuated by higher total non-arrhythmic mortality. While septuagenarians and octogenarians have higher annual all-cause mortality rates, ICD therapy may remain effective in selected patients at high risk of arrhythmic death and with minimum comorbidities despite advanced age. ICD implantation among the elderly, as a group, may not be cost-effective, but the procedure may reach cost-effectiveness in those expected to live more than 5-7years after implantation. Elderly patients usually experience significant functional improvement after CRT, similar to that observed in middle-aged patients. Management of CRT non-responders remains globally the same, while considering a less aggressive approach in terms of reinterventions (revision of left ventricular [LV] lead placement, addition of a right ventricular or LV lead, LV endocardial pacing configuration). Overall, physiological age, general status and comorbidities rather than chronological age per se should be the decisive factors in making a decision about device implantation selection for survival and well-being benefit in elderly patients.

Subclinical atrial fibrillation: A new entity and what it means?

New device technologies allow for detection of clinically silent atrial fibrillation. This new entity has been associated with increased risk for stroke, even if detected for only relatively brief time periods. Current practice guidelines do not provide recommendations on how to approach this new clinical entity.

Stroke prevention in atrial fibrillation

Atrial fibrillation is found in a third of all ischaemic strokes, even more after post-stroke atrial fibrillation monitoring. Data from stroke registries show that both unknown and untreated or under treated atrial fibrillation is responsible for most of these strokes, which are often fatal or debilitating. Most could be prevented if efforts were directed towards detection of atrial fibrillation before stroke occurs, through screening or case finding, and treatment of all patients with atrial fibrillation at increased risk of stroke with well-controlled vitamin K antagonists or non-vitamin K antagonist anticoagulants. The default strategy should be to offer anticoagulant thromboprophylaxis to all patients with atrial fibrillation unless defined as truly low risk by simple validated risk scores, such as CHA2DS2-VASc. Assessment of bleeding risk using the HAS-BLED score should focus attention on reversible bleeding risk factors. Finally, patients need support from physicians and various other sources to start anticoagulant treatment and to ensure adherence to and persistence with treatment in the long term.

Perioperative atrial fibrillation: a systematic review of evolving therapeutic options in pharmacologic and procedural management

Given the high incidence of atrial fibrillation (AF) in the surgical population and the associated morbidity, physicians managing these complicated patients in the perioperative period need to be aware of the new and emerging trends in its therapy. The cornerstones of AF management have always been rate/rhythm control as well as anticoagulation. Restoration of sinus rhythm remains the fundamental philosophy as it maintains the atrial contribution to cardiac output and improves ventricular function. The recent years have seen a dramatic increase in the number of randomized AF trials that have made significant advances to our understanding of both pharmacologic and procedural management, from the introduction of the new generation of oral anticoagulants (NOAC's) to catheter approaches for AF ablation. This paper will summarize the newest data that will affect the perioperative management of these patients.

Stroke risk assessment in atrial fibrillation: risk factors and markers of atrial myopathy

Atrial fibrillation (AF) is a complex phenomenon associated with electrical, mechanical, and structural abnormalities of the atria. Ischaemic stroke in AF is only partially understood, but the mechanisms are known to be related to the atrial substrate as well as the atrial rhythm. The temporal dissociation between timing of AF and occurrence of stroke has led to the hypothesis that fibrotic, prothrombotic atrial tissue is an important cause of thrombus formation in patients with AF, independent of the atrial rhythm. Current stroke risk scores are practical, but limited in their capacity to predict stroke risk accurately in individual patients. Stroke prediction might be improved by the addition of emerging risk factors, many of which are expressions of atrial fibrosis. The use of novel parameters, including clinical criteria, biomarkers, and imaging data, might improve stroke risk prediction and inform on optimal treatment for patients with AF and perhaps individuals only at risk of AF.