Long-term health-related quality of life and rhythm outcomes of catheter ablation versus antiarrhythmic drugs in patients with atrial fibrillation.

BACKGROUND: Data on long-term effects of catheter ablation vs antiarrhythmic drugs (AADs) on health-related quality of life (HRQoL) and atrial fibrillation (AF) burden are limited. OBJECTIVE: The study aimed to assess long-term HRQoL and rhythm data in patients with symptomatic AF. METHODS: The 75 patients who underwent ablation and 74 receiving AAD in the Catheter Ablation compared with Pharmacological Therapy for Atrial Fibrillation trial were followed for 48 months. The General Health subscale of the 36-Item Short-Form Health Survey, time to first AF episode ≥1 hour, and AF burden, recorded by implantable cardiac monitors, were compared. RESULTS: One hundred forty-seven patients completed follow-up, with 7 crossovers in the ablation group and 34 crossovers in the AAD group. General Health improved by ablation from a median of 62 points at baseline to 79.2 points at follow-up (P < .001) and by AAD from a median of 67 to 77 points (P < .001), without treatment differences (P = .77). Time to first AF episode ≥1 hour was longer (median 257 days in the ablation group vs 180 days in the AAD group; P = .025). The cumulative AF burden during follow-up was lower in the ablation group (median 0.3%; interquartile range [IQR] 0%-1.4%) than in the AAD group (1.6%; IQR 0.1%-11.0%) (P = .01). The cumulative reduction in AF burden compared with baseline was greater in the ablation group (median -89.5%; IQR -98.4% to -51.3%) than in the AAD group (-52.7%; IQR -92.6% to 263.6%); P < .001). CONCLUSION: HRQoL improvement at long-term did not differ between ablation and AAD groups despite a larger reduction in AF burden after ablation. The results should be interpreted in the light of a high crossover rate in the AAD group.

Age-Dependent Detection of Atrial Fibrillation with Implantable Cardiac Monitors in Patients with Cryptogenic Stroke.

Background Continuous monitoring using implantable cardiac monitors (ICMs) results in atrial fibrillation (AF) detection rates of up to 30% in patients with cryptogenic stroke (CS). Although higher age is an independent risk factor for AF, there are no age-specific recommendations for the implantation of ICM. Objective The aim of this study was to analyze age-related AF rates in patients with CS and continuous rhythm monitoring, to determine the rates of oral anticoagulation (OAC) and recurrent cerebrovascular events (stroke or transient ischemic attack) in patients with ICM-detected AF, and to describe the temporal relationship of AF detection and recurrent cerebrovascular events. Methods In this observational study, patients with CS provided with ICMs were systematically followed. All patients underwent 72-hour electrocardiography monitoring, transcranial Doppler ultrasound, and transthoracic echocardiography prior to ICM insertion. Follow-up included a regular outpatient presentation every 3 months with medical history, physical examination, and interrogation of the ICM. Results One-hundred eighty-six patients (mean age: 65 ± 12 years, 54% female) were included in this analysis. AF was detected in 6, 27, 56, and 65% ( p < 0.001) of patients aged less than 60, 60 to 69, 70 to 79, and more than or equal to 80 years, respectively. All patients with AF under 60 years had an impaired left ventricular systolic function. OAC was initiated in 85% of the patients with AF. Recurrent cerebrovascular events occurred in 34 patients of whom 14 had a diagnosis of AF. In nine patients, AF was diagnosed before the occurrence of a recurrent cerebrovascular event. Conclusion AF prevalence increased with age and was absent in CS patients younger than 60 years and with preserved left ventricular ejection fraction. The temporal relationship of AF and recurrent cerebrovascular events was weak.

Ambulatory Risk Stratification for Worsening Heart Failure in Patients with Reduced and Preserved Ejection Fraction Using Diagnostic Parameters Available in Implantable Cardiac Monitors.

BACKGROUND: Ambulatory risk stratification for worsening heart failure (HF) using diagnostics measured by insertable cardiac monitors (ICM) may depend on the left ventricular ejection fraction (LVEF). We evaluated risk stratification performance in patients with reduced versus preserved LVEF. METHODS: ICM patients with a history of HF events (HFEs) were included from the Optum® de-identified Electronic Health Record dataset merged with ICM device-collected data during 2007-2021. ICM measures nighttime heart rate (NHR), heart rate variability (HRV), atrial fibrillation (AF) burden, rate during AF, and activity duration (ACT) daily. Each diagnostic was categorized into high, medium, or low risk using previously defined features. HFEs were HF-related inpatient, observation unit, or emergency department stays with IV diuresis administration. Patients were divided into two cohorts: LVEF ≤ 40% and LVEF > 40%. A marginal Cox proportional hazards model compared HFEs for different risk groups. RESULTS: A total of 1020 ICM patients with 18,383 follow-up months and 301 months with HFEs (1.6%) were included. Monthly evaluations with a high risk were 2.3, 4.2, 5.0, and 4.5 times (p < 0.001 for all) more likely to have HFEs in the next 30 days compared to those with a low risk for AF, ACT, NHR, and HRV, respectively. HFE rates were higher for patients with LVEF > 40% compared to LVEF ≤ 40% (2.0% vs. 1.3%), and the relative risk between high-risk and low-risk for each diagnostic parameter was higher for patients with LVEF ≤ 40%. CONCLUSIONS: Diagnostics measured by ICM identified patients at risk for impending HFEs. Patients with preserved LVEF showed a higher absolute risk, and the relative risk between risk groups was higher in patients with reduced LVEF.

Heart rate characteristic based modelling of atrial fibrillatory rate using implanted cardiac monitor data.

Objective. The objective of the present study is to investigate the feasibility of using heart rate characteristics to estimate atrial fibrillatory rate (AFR) in a cohort of atrial fibrillation (AF) patients continuously monitored with an implantable cardiac monitor. We will use a mixed model approach to investigate population effect and patient specific effects of heart rate characteristics on AFR, and will correct for the effect of previous ablations, episode duration, and onset date and time.Approach. The f-wave signals, from which AFR is estimated, were extracted using a QRST cancellation process of the AF episodes in a cohort of 99 patients (67% male; 57 ± 12 years) monitored for 9.2(0.2-24.3) months as median(min-max). The AFR from 2453 f-wave signals included in the analysis was estimated using a model-based approach. The association between AFR and heart rate characteristics, prior ablations, and episode-related features were modelled using fixed-effect and mixed-effect modelling approaches.Main results. The mixed-effect models had a better fit to the data than fixed-effect models showing h.c. of determination (R2 = 0.49 versusR2 = 0.04) when relating the variations of AFR to the heart rate features. However, when correcting for the other factors, the mixed-effect model showed the best fit (R2 = 0.04). AFR was found to be significantly affected by previous catheter ablations (p< 0.05), episode duration (p< 0.05), and irregularity of theRRinterval series (p< 0.05).Significance. Mixed-effect models are more suitable for AFR modelling. AFR was shown to be faster in episodes with longer duration, less organizedRRintervals and after several ablation procedures.

An ensemble of features based deep learning neural network for reduction of inappropriate atrial fibrillation detection in implantable cardiac monitors.

Background: Multiple studies have reported on classification of raw electrocardiograms (ECGs) using convolutional neural networks (CNNs). Objective: We investigated an application-specific CNN using a custom ensemble of features designed based on characteristics of the ECG during atrial fibrillation (AF) to reduce inappropriate AF detections in implantable cardiac monitors (ICMs). Methods: An ensemble of features was developed and combined to form an input signal for the CNN. The features were based on the morphological characteristics of AF, incoherence of RR intervals, and the fact that AF begets more AF. A custom CNN model and the RESNET18 model were trained using ICM-detected AF episodes that were adjudicated to be true AF or false detections. The trained models were evaluated using a test dataset from independent patients. Results: The training and validation datasets consisted of 31,757 AF episodes (2516 patients) and 28,506 false episodes (2126 patients). The validation set (20% randomly chosen episodes of each type) had an area under the curve of 0.996 for custom CNN (0.993 for RESNET18). Thresholds were chosen to obtain a relative sensitivity and specificity of 99.2% and 92.8%, respectively (99.2% and 87.9% for RESNET18, respectively). The performance in the independent test set (4546 AF episodes from 418 patients; 5384 false episodes from 605 patients) showed an area under the curve of 0.993 (0.991 for RESNET18) and relative sensitivity and specificity of 98.7% and 91.4%, respectively, at chosen thresholds (98.9% and 88.2% for RESNET18, respectively). Conclusion: An ensemble of features-based CNNs was developed that reduced inappropriate AF detection in ICMs by over 90% while preserving sensitivity.

Monitoring and diagnosis of intermittent arrhythmias: evidence-based guidance and role of novel monitoring strategies.

Technological advances have made diagnosis of heart rhythm disturbances much easier, with a wide variety of options, including single-lead portable devices, smartphones/watches to sophisticated implantable cardiac monitors, allowing accurate data to be collected over different time periods depending on symptoms frequency. This review provides an overview of the novel and existing heart rhythm testing options, including a description of the supporting evidence for their use. A description of each of the tests is provided, along with discussion of their advantages and limitations. This is intended to help clinicians towards choosing the most appropriate test, thus improving diagnostic yield management of patients with suspected arrhythmias.

Clinical applications of heart rhythm monitoring tools in symptomatic patients and for screening in high-risk groups.

Recent technological advances have facilitated and diversified the options available for the diagnosis of cardiac arrhythmias. Ranging from simple resting or exercise electrocardiograms to more sophisticated and expensive smartphones and implantable cardiac monitors. These tests and devices may be used for varying periods of time depending on symptom frequency. The choice of the most appropriate heart rhythm test should be guided by clinical evaluation and optimized following accurate characterization of underlying symptoms, 'red flags', risk factors, and consideration of cost-effectiveness of the different tests. This review provides evidence-based guidance for assessing suspected arrhythmia in patients who present with symptoms or in the context of screening, such as atrial fibrillation or advanced conduction disturbances following transcatheter aortic valve implantation in high-risk groups. This is intended to help clinicians choose the most appropriate diagnostic tool to facilitate the management of patients with suspected arrhythmias.

Prediction of occult atrial fibrillation in patients after cryptogenic stroke and transient ischaemic attack: PROACTIA.

AIMS: Studies with implantable cardiac monitors (ICMs) show that one-third of patients with cryptogenic stroke/transient ischaemic attack (TIA) have episodes of subclinical atrial fibrillation (SCAF) and benefit switching from antiplatelet- to anticoagulant therapy. However, ICMs are costly and resource demanding. We aimed to build a score based on participant's baseline characteristics that could assess individual risk of SCAF. METHODS AND RESULTS: In a prospective study, 236 eligible patients with a final diagnosis of cryptogenic stroke/TIA had an ICM implantated during the index hospitalization. Pre-specified evaluated variables were: CHA2DS2-VASc, P-wave duration, P-wave morphology, premature atrial beats (PAC)/24 h, supraventricular tachycardia/24 h, left atrial end-systolic volume index (LAVI), Troponin-T, NT-proBNP, and D-dimer. SCAF was detected in 84 patients (36%). All pre-specified variables were significantly associated with SCAF detection in univariate analysis. P-wave duration, followed by PAC/24 h, NT-proBNP, and LAVI, had the largest ratio of SCAF prevalence between its upper and lower quartiles (3.3, vs. 3.2, vs. 3.1 vs. 2.8, respectively). However, in a multivariate analysis, only PAC/24t, P-wave duration, P-wave morphology, and LAVIs remained significant predictors and were included in the PROACTIA score. Subclinical atrial fibrillation prevalence was 75% in the highest vs. 10% in the lowest quartile of the PROACTIA score with a 10-fold higher number of patients with an atrial fibrillation burden >6 h in the highest vs. the lowest quartile. CONCLUSION: The PROACTIA score can identify patients with cryptogenic stroke/TIA at risk of subsequent SCAF detection. The large difference in SCAF prevalence between groups may provide a basis for future tailored therapy. CLINICAL TRIAL REGISTRATION: Clinical Trial Registration: ClinicalTrials.gov; NCT02725944.

ESC Working Group on e-Cardiology Position Paper: accuracy and reliability of electrocardiogram monitoring in the detection of atrial fibrillation in cryptogenic stroke patients : In collaboration with the Council on Stroke, the European Heart Rhythm Association, and the Digital Health Committee.

The role of subclinical atrial fibrillation as a cause of cryptogenic stroke is unambiguously established. Long-term electrocardiogram (ECG) monitoring remains the sole method for determining its presence following a negative initial workup. This position paper of the European Society of Cardiology Working Group on e-Cardiology first presents the definition, epidemiology, and clinical impact of cryptogenic ischaemic stroke, as well as its aetiopathogenic association with occult atrial fibrillation. Then, classification methods for ischaemic stroke will be discussed, along with their value in providing meaningful guidance for further diagnostic efforts, given disappointing findings of studies based on the embolic stroke of unknown significance construct. Patient selection criteria for long-term ECG monitoring, crucial for determining pre-test probability of subclinical atrial fibrillation, will also be discussed. Subsequently, the two major classes of long-term ECG monitoring tools (non-invasive and invasive) will be presented, with a discussion of each method's pitfalls and related algorithms to improve diagnostic yield and accuracy. Although novel mobile health (mHealth) devices, including smartphones and smartwatches, have dramatically increased atrial fibrillation detection post ischaemic stroke, the latest evidence appears to favour implantable cardiac monitors as the modality of choice; however, the answer to whether they should constitute the initial diagnostic choice for all cryptogenic stroke patients remains elusive. Finally, institutional and organizational issues, such as reimbursement, responsibility for patient management, data ownership, and handling will be briefly touched upon, despite the fact that guidance remains scarce and widespread clinical application and experience are the most likely sources for definite answers.

[Remote monitoring of implantable monitors : Towards coverage ? Evaluation of the procedure by the French National Authority for Health]. / Télésurveillance des Moniteurs cardiaques implantables : Vers une prise en charge ? Évaluation de l'acte par la Haute autorité de santé.

Implantable cardiac monitors are recommended and reimbursed in two specific cases: the etiological diagnosis of unexplained recurrent syncope and the etiological diagnosis of a cryptogenic ischemic stroke. According to the French National Authority for Health (HAS), remote monitoring "leads to early diagnosis and therapeutic care". However, remote tracking of these devices for diagnostic purposes is not included in the ETAPES program, which will end soon. This article presents a summary of the evaluation by HAS of the remote monitoring of implantable cardiac monitors. It also addresses the question of its reimbursement, as for therapeutic implantable devices.

Second-generation laser balloon ablation for the treatment of atrial fibrillation assessed by continuous rhythm monitoring: the LIGHT-AF study.

AIMS: Balloon-based technologies have been developed to simplify catheter ablation of atrial fibrillation (AF), to improve the clinical outcome of the procedure and to achieve durable pulmonary vein isolation (PVI). The objective of this study is to evaluate the safety and efficacy of second-generation laser balloon (LB2) ablation in the treatment of AF using a continuous cardiac rhythm monitoring strategy. Atrial tachyarrhythmias (ATas) recurrences were assessed with implantable cardiac monitors (ICMs) or devices. METHODS AND RESULTS: All patients underwent LB2 ablation procedure. The primary endpoint was the first recurrence of any, >5.5 and >24 h duration ATas after the blanking period (90 days). In-hospital visits were performed at 3, 6, and 12 months. Seventy-three patients (68% male, mean age 59.8 ± 11.3) were included in the study. The average procedure, fluoroscopy, and laser ablation times were 81.5 ± 30.1, 21.5 ± 12.4, and 33.8 ± 9.7, respectively. All PVs were isolated using the LB2 with no need of touch-up using focal catheters. No major complications occurred during or after the procedures. The one-year freedom from recurrences was 66.9% (95% CI: 57.0-76.7%), 81.0% (69.5-88.5%), and 86.8% (76.1-92.9%) considering any, 5.5-h and 24-h cut-off duration, respectively. At 3, 6, and 12 months, any ATas was recorded in 22%, 32%, and 25% of patients, with a ≥5% arrhythmic burden documented in 4%, 5%, and 3%, respectively. Few patients reported AF-related symptoms (7%, 8%, and 5%). CONCLUSION: LB2 ablation is a safe and effective procedure, showing a high freedom from recurrences and low arrhythmic burden as documented by a continuous rhythm monitoring strategy.

Insertable cardiac monitors for detection of atrial fibrillation after cryptogenic stroke: a meta-analysis.

BACKGROUND: In recent years, the implantable cardiac monitors (ICM) have enhanced the recognition ability of atrial fibrillation (AF), which makes ICM have a new application in AF detection. We conducted a meta-analysis to determine the total incidence of newly found AF detected by ICM after cryptogenic stroke and to evaluate the factors related to the detection of AF. METHODS: A literature search was conducted in the PubMed, EMBASE, Web of Science, and Cochrane library databases until March 1, 2020. Studies that reported the detection rate of AF using ICM in cryptogenic stroke patients with negative initial AF screening were analyzed. RESULTS: A total of 23 studies were included. The overall proportion of AF detected by ICM in cryptogenic stroke patients was 25% (95% confidence interval [CI], 22-29%). The rate of AF detected by ICM was independently related to both cardiac monitoring time (coefficient = 0.0003; 95% CI, 0.0001-0.0005; P = 0.0001) and CHA2DS2-VASc score (coefficient = 0.0834; 95% CI, 0.0339-0.1329; P = 0.001). In subgroup analysis, we found a significant difference in the detection rate of AF for monitoring duration (< 6 months: 9.6% [95% CI, 4.4-16.4%]; ≥ 6 and ≤ 12 months: 19.3% [95% CI, 15.9-23.0%]; > 12 and ≤ 24 months: 23.6% [95% CI, 19.9-27.5%]; > 24 months and ≤ 36 months: 36.5% [95% CI, 24.2-49.9%]; P < 0.001), and continent (Europe: 26.5% [95% CI, 22.2-31.0%]; North America: 16.0% [95% CI, 10.3-22.6%]; Asia: 17.4% [95% CI, 12.4-23.0%]; P = 0.005). CONCLUSIONS: The longer the time of ICM monitoring after cryptogenic stroke, the higher the detection rate of AF. Further research is still needed to determine the optimal duration of long-term cardiac monitoring.

[Clinical differential indication : Wearables vs implantables]. / Klinische Differenzialindikation : Wearables vs. Implantables.

In order to document arrhythmias, indicated due to symptoms or for prognostic purposes, both invasive and noninvasive possibilities for ECG monitoring are available. The choice of the device for monitoring depends mainly on the frequency of arrhythmias. If they occur less than once a month, long-term monitoring becomes necessary which either continuously monitors the rhythm by an implantable device (implantables) or by wearable systems (wearables) which usually register the ECG discontinuously. Because wearables, e.g. smartphones, are basically ubiquitously available, they may be used for ECG monitoring. This paper comments on the use of implantables and wearables for the detection of atrial fibrillation and the documentation of symptomatic arrhythmias in syncope or palpitations.

Implantable cardiac monitors to detect atrial fibrillation after cryptogenic stroke: a systematic review and economic evaluation.

BACKGROUND: Cryptogenic stroke is a stroke for which no cause is identified after standard diagnostic tests. Long-term implantable cardiac monitors may be better at diagnosing atrial fibrillation and provide an opportunity to reduce the risk of stroke recurrence with anticoagulants. OBJECTIVES: The objectives were to assess the diagnostic test accuracy, clinical effectiveness and cost-effectiveness of three implantable monitors [BioMonitor 2-AF™ (Biotronik SE & Co. KG, Berlin, Germany), Confirm Rx™ (Abbott Laboratories, Lake Bluff, IL, USA) and Reveal LINQ™ (Medtronic plc, Minneapolis, MN, USA)] in patients who have had a cryptogenic stroke and for whom no atrial fibrillation is detected after 24 hours of external electrocardiographic monitoring. DATA SOURCES: MEDLINE, EMBASE, The Cochrane Library, Database of Abstracts of Reviews of Effects and Health Technology Assessment databases were searched from inception until September 2018. REVIEW METHODS: A systematic review was undertaken. Two reviewers agreed on studies for inclusion and performed quality assessment using the Cochrane Risk of Bias 2.0 tool. Results were discussed narratively because there were insufficient data for synthesis. A two-stage de novo economic model was developed: (1) a short-term patient flow model to identify cryptogenic stroke patients who have had atrial fibrillation detected and been prescribed anticoagulation treatment (rather than remaining on antiplatelet treatment) and (2) a long-term Markov model that captured the lifetime costs and benefits of patients on either anticoagulation or antiplatelet treatment. RESULTS: One randomised controlled trial, Cryptogenic Stroke and underlying Atrial Fibrillation (CRYSTAL-AF) (Sanna T, Diener HC, Passman RS, Di Lazzaro V, Bernstein RA, Morillo CA, et al. Cryptogenic stroke and underlying atrial fibrillation. N Engl J Med 2014;370:2478-86), was identified, and no diagnostic test accuracy study was identified. The CRYSTAL-AF trial compared the Reveal™ XT (a Reveal LINQ predecessor) (Medtronic plc) monitor with standard of care monitoring. Twenty-six single-arm observational studies for the Reveal devices were also identified. The only data for BioMonitor 2-AF or Confirm Rx were from mixed population studies supplied by the companies. Atrial fibrillation detection in the CRYSTAL-AF trial was higher with the Reveal XT than with standard monitoring at all time points. By 36 months, atrial fibrillation was detected in 19% of patients with an implantable cardiac monitor and in 2.3% of patients receiving conventional follow-up. The 26 observational studies demonstrated that, even in a cryptogenic stroke population, atrial fibrillation detection rates are highly variable and most cases are asymptomatic; therefore, they probably would not have been picked up without an implantable cardiac monitor. Device-related adverse events, such as pain and infection, were low in all studies. The de novo economic model produced incremental cost effectiveness ratios comparing implantable cardiac monitors with standard of care monitoring to detect atrial fibrillation in cryptogenic stroke patients based on data for the Reveal XT device, which can be related to Reveal LINQ. The BioMonitor 2-AF and Confirm RX were included in the analysis by making a strong assumption of equivalence with Reveal LINQ. The results indicate that implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold. When each device is compared incrementally, BioMonitor 2-AF dominates Reveal LINQ and Confirm RX. LIMITATIONS: The cost-effectiveness analysis for implantable cardiac monitors is based on a strong assumption of clinical equivalence and should be interpreted with caution. CONCLUSIONS: All three implantable cardiac monitors could be considered cost-effective at a £20,000-30,000 threshold, compared with standard of care monitoring, for cryptogenic stroke patients with no atrial fibrillation detected after 24 hours of external electrocardiographic monitoring; however, further clinical studies are required to confirm their efficacy in cryptogenic stroke patients. STUDY REGISTRATION: This study is registered as PROSPERO CRD42018109216. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 5. See the NIHR Journals Library website for further project information.

An abnormal heart rhythm (atrial fibrillation) is an important cause of stroke. Clots form in the heart, break off, pass into blood vessels in the head and block the blood supply to parts of the brain. This is important to diagnose because atrial fibrillation can be treated with blood-thinning drugs, which can prevent further stroke. For this reason, all patients with stroke are tested for atrial fibrillation. Unfortunately, the standard tests, which include 24 hours of outpatient external heart monitoring, may miss the condition. Implantable cardiac monitors, which are small devices placed beneath the skin of the chest that can monitor the heart for up to 4 years, may be better than the standard tests. This study compared three different implantable cardiac monitors [BioMonitor 2-AF™ (Biotronik SE & Co. KG, Berlin, Germany), Confirm Rx™ (Abbott Laboratories, Lake Bluff, IL, USA) and Reveal LINQ™ (Medtronic plc, Minneapolis, MN, USA)] to determine how effective they are at detecting atrial fibrillation in people who have had a cryptogenic stroke (a stroke for which no cause is identified), whether or not they are better than standard monitoring and whether or not they offer good value for money. No evidence was found that directly compared the three implantable monitors in cryptogenic stroke patients. The limited evidence found suggested that all three monitors had few side effects; only one monitor (Reveal LINQ) had evidence that it was better than standard monitoring. By 36 months, 19% of patients had atrial fibrillation detected by Reveal LINQ compared with only 2.3% with conventional monitoring. There was insufficient information for the other monitors. Overall, implantable monitors offer value for money when compared with standard monitoring for people who have had a cryptogenic stroke and for whom atrial fibrillation has not been detected with standard tests.

Phased multipolar radiofrequency pulmonary vein isolation is as effective and safe as conventional irrigated point-to-point ablation. A prospective randomised 1-year implantable cardiac monitoring device follow-up trial.

PURPOSE: Pulmonary vein isolation (PVI) is conventionally performed using 3D electroanatomical mapping to guide point-to-point ablation. The Pulmonary Vein Ablation Catheter (PVAC)® is a phased multipolar ablation (PMRA) catheter designed for rapid PVI using radiological anatomical information. Comparison of these methods of PVI using continuous beat-to-beat monitoring was undertaken. METHODS: Fifty patients with drug-refractory, symptomatic paroxysmal atrial fibrillation (PAF) were recruited. Patients all had REVEAL® XT ILR or a DDDRP permanent pacemaker (PPM) inserted prior to PVI. PPM was programmed to monitoring mode (ODO). Patients were randomised 1:1 to undergo PVI with either point-to-point irrigated radiofrequency ablation (Conv) or PMRA technology. Follow-up was performed at 0, 3, 6, 9, and 12 months using Holter downloads to assess arrhythmia burden. Outcomes were examined following a 3-month blanking period. RESULTS: The AF burden pre-ablation, at 3-month and at 12-month post-ablations, was not significantly different (pre-ablation AF burdens (mean ± SE) Conv 16.6 ± 5.0%, PVAC 17.0 ± 5.6 %, 3 months Conv 4.0 ± 1.6 %, PVAC 4.7 ± 1.5%, 12 months Conv 4.3 ± 2.3%, PVAC 3.8 ± 1.5%). In both groups, there was a significant reduction in AF burden from pre-ablation (at 3 months p = 0.01, p = 0.04, at 12 months p = 0.04, p = 0.03 for Conv and PMRA groups, respectively). Overall success rate for zero AF recurrence at 12 months was 54%. CONCLUSION: PMRA PVI is comparable to conventional technology for AF extinction at 1 year. The PMRA is as safe as conventional technology but enables the operator to perform the procedure faster. Device monitored success rates were lower than other studies not utilising such intensive monitoring confirming that sporadic ECG monitoring is not sufficient to detect all AF recurrence. TRIAL REGISTRATION: NCT01095770. URL: https://clinicaltrials.gov/ct2/show/NCT01095770.

Anticoagulation after catheter ablation of atrial fibrillation guided by implantable cardiac monitors.

BACKGROUND: Discontinuation of oral anticoagulation (OAC) after catheter ablation of atrial fibrillation (AF) is not recommended in patients with elevated CHADS2 scores. However, a low incidence of thromboembolic events is reported when OAC is stopped in these patients. We introduce an algorithm for discontinuation of OAC after ablation based on the AF burden documented by implantable cardiac monitors (ICM). METHODS: Sixty-five patients with CHADS2 scores 1-3 free from AF 3 months after ablation (AF ablation [n = 49] or ablation of possible AF triggers [n = 16]) were included. One day after implantation of the ICM, OAC was stopped. Patients performed a daily interrogation of the ICM which was programmed to alarm the patient if daily AF burden exceeded 1 hour. Study end point was the first recurrence of a daily AF burden ≥1 hour or a thromboembolic event, which both triggered reinitiation of OAC. RESULTS: During a follow-up time of 32 ± 12 months (126 patient-years), 41 of the 65 patients (63%) had an AF burden <1 h/day and were able to stay off OAC. Twenty-one patients (32%) had to reinitiate OAC due to an AF burden ≥1 hour and three patients due to other reasons. No stroke, transitory ischemic attack, or other thromboembolic event was observed during follow-up. CONCLUSIONS: Rhythm monitoring by ICM in patients who have stopped OAC after catheter ablation of AF or ablation of possible AF triggers seems to be a safe and promising method to monitor for AF recurrence. Within 1.3 years after ablation, about two-thirds of patients were able to stay off OAC.