Atrial High-rate Episodes Research Articles

The role of biomarkers, sleep apnea and echocardiography as predictors of atrial fibrillation in a pacemaker population

Abstract Funding Acknowledgements Type of funding sources: None. Background Sleep apnea, dilated left atrial has been related to a higher possibility to develop atrial fibrillation (AF). Some pacemakers are able to detect periods of apnea during the sleeping time obtaining a respiratory disturbance index (RDI) related to sleep apnea (SA), as well as atrial high rate episodes (AHREs) that are also predictors of AF. Another possible predictor of AF is galectin-3, a biomarker related to fibrotic phenomena. This study aims to evaluate the relationship between ARI and AHRE detection, as well as the relationship between left atrial size measured by echocardiography and some biomarkers with the development of AHREs. Methods This is a single-centre, prospective, non-randomized, descriptive study carried out in a tertiary hospital, including patients with dual-chamber pacemaker able to detect SA, initially in sinus rhythm. Patients were included at the implantation date, between November 2015 and November 2018, and medium follow-up was 2 years. Those with a previous diagnosis of AF were not included. In a baseline visit, clinical, anthropometric characteristics, as well as echocardiography and analytical parameters were obtained, including NTproBNP, galectin-3 and ST-2. In addition to the baseline visit, device interrogation visits at six months, one year and tho years in order to obtain atrial activity and SA registers were performed. Those whose apnea recordings were illegible were excluded from the analysis. We performed a descriptive statistical analysis with Microsoft Excel. Results 102 patients with dual chamber pacemaker were included. 79 of the pacemakers provided legible apnea and atrial activity recordings. 22 of them showed an RDI>20 in more than 75% of the nights, and 38 of them recorded AHRE longer than 6 minutes in 24 hours. Tables 1 and 2 show baseline characteristics and the AHRE (episodes with duration >6 minutes) and RDI recordings suggestive of severe SA (RDI>20 in more than 75% of the nights). Differences in AHRE between both RDI groups did not reach statistical significance. After univariate analysis, the multivariate analysis showed significant relationship between AHRE >6 minutes and the galectin-3 level at baseline as well as between AHRE>6 minutes and the left atrial indexed volume at baseline. Conclusion In our study, 48% of the pacemakers registered AHRE longer than 6 minutes in 24 hours. No statistical relationship between RDI and AHRE was found. Baseline galectin-3 level and left atrial indexed volume appeared to be related to the development of AHRE in the follow-up.

Effects of antiarrhythmics on atrial high rate episodes and progression to clinical atrial fibrillation (ANTI-AHRE)

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial High Rates Episodes (AHRE) are associated with progression to clinical atrial fibrillation (AF), stroke, increased risk of MACE and increased mortality (1-4). Although oral anticoagulation should be initiated in patients with CHADs-VASc score ≥ 2 and episode duration ≥ 24h, treatment of AHRE with antiarrhythmics was not investigated so far. Purpose This study aimed to assess the effects of antiarrhythmic treatment on AHRE and its impact on the progression to clinical AF and AHRE burden. Methods This study included patients with AHRE duration ≥ 24h detected by dual-chamber pacemakers, without a previous diagnosis of AF and treatment with antiarrhythmics. Nominal settings with high atrial rate criterion programmed to 200 beats/min were used for AHRE detection. Patients were randomized to the Intervention (n=169) and Control Group (n=138). Patients in the Intervention Group received antiarrhythmic treatment (Ic antiarrhythmics (n=54), beta-blockers (n=58) and amiodarone (n=57)). The primary endpoint was progression to clinical AF and the secondary endpoint was AHRE burden. Results A total of 307 were included in the study, with a mean age of 71.4±8.15, 166 (54.07%) females and a mean follow-up 20.84±5.04 months. The baseline characteristics did not differ significantly between groups. During the follow-up, 50 patients (36.23%) from the Control group developed clinical AF. In groups of patients treated with Ic antiarrhythmics, beta-blockers and amiodarone, clinical AF developed in 11 (20.37%), 25 (25.86%) and 5 (8.77%) patients, respectively (p<0.001). Average time to clinical AF progression was significantly longer in groups of patients treated with antiarrhythmics (Ic antiarrhythmics, beta-blockers and amiodarone) compared to the Control group (17.7, 17.2, 19.0 vs 15.9 months, respectively, p<0.001). The Kaplan-Meier plot of freedom from clinical AF is given in Figure 1. Amiodarone prolonged the time to clinical AF progression significantly compared to beta-blockers (p=0.017), while a trend was observed compared to Ic antiarrhythmics (p=0.057). No significant differences between Ic antiarrhythmics and beta-blockers were observed in time to clinical AF progression (p=0.567). The AHRE burden was significantly lower in the Intervention group compared to the Control group (6.9% vs 15.4%, p<0.001). Amiodarone was superior in lowering the AHRE burden when compared to Ic antiarrhythmics and beta-blockers (2.1% vs 5.6% and 7.8%, respectively, p<0.001), while no significant differences were observed between Ic antiarrhythmics and beta-blockers (p=0.18) Conclusion Initiating antiarrhythmics for AHRE episodes leads to a lower AHRE burden and progression to clinical AF. Randomized clinical trials are needed to investigate further the early antiarrhythmic treatment of AHRE without clinical AF.

Invasive electrophysiology study guided loop recorder implantation in myotonic dystrophy type 1: a prospective single-center study

Abstract Funding Acknowledgements Type of funding sources: None. Introduction In one third of the patients with myotonic dystrophy type 1 (DMT1) the cause of death is of cardiac origin. The most common cardiac manifestations are arrhythmias and conduction disturbances. Purpose Due to its extreme long monitoring properties, implantable loop recorders (ILRs) are highly suitable to detect rare cardiac arrhythmias. To date, there are only limited data using ILRs in DMT1. We aimed to evaluate the role of the invasive electrophysiology study (EPS)-guided loop recorder implantation in patients with DMT. Methods In our prospective study 18 genetically confirmed DMT1 patients underwent non-invasive cardiac examination including transthoracic echocardiography, 24-hour Holter monitoring and surface ECG. In addition, EPS was performed in all cases to evaluate the risk of sudden cardiac death and infra-Hisian conduction properties. Based on the performed non-invasive diagnostic evaluation and EPS findings, patients were divided into low, intermediate and high-risk groups. For patients with normal investigation results and normal HV interval (<55 ms) only annual cardiac follow-up visits were planned (low-risk group). Patients with increased PR interval (>240 ms), QRS duration (>120 ms), or slightly prolonged HV interval (55-70 ms) underwent implantable loop recorder (ILR) implantation (intermediate-risk group). Permanent pacemaker (PM) or implantable cardiac defibrillator (ICD) was implanted in patients with 2nd/3rd degree atrioventricular block (AVB), significantly prolonged HV interval (>100 ms) or if sustained ventricular tachyarrhythmia could be induced during EPS. All patients were followed for at least 3 years. Results According to our study criteria, 8 patients could be categorized as "intermediate risk", 7 of them received implantable loop recorder (ILR). 1 ILR had to be removed 3 weeks after implantation due to skin infarction. During three-years of follow-up, 2 patients had many asymptomatic atrial high-rate episodes, but no 2nd or 3rd degree AVB, significant asystole or malignant ventricular arrhythmia were detected. Conclusions Our single-center prospective study examined the EPS-guided ILR implantation for the risk stratification of DMT1 patients for the first time. A more extensive, multicenter study is warranted to define optimal management of DMT1 patients with slightly impaired infrahisian conduction.

Atrial high-rate episodes intensify R2CHA2DS2-VASc score for prognostic stratification in pacemaker patients

Patients with device detected atrial high-rate episodes (AHRE) have an increased risk of MACE. The R2CHA2DS2-VASc, CHADS2, R2CHADS2 and CHA2DS2-VASc score have been investigated for predicting major adverse cardiovascular events (MACE) in different groups of patients. We aimed to evaluate the R2CHA2DS2-VASc score in combination with AHRE ≥ 6 min for predicting MACE in patients with dual-chamber PPM but no prior atrial fibrillation (AF). We retrospectively enrolled 376 consecutive patients undergoing dual-chamber PPM implantation and no prior AF. The primary endpoint was subsequent MACE. For all patients in the cohort, CHADS2, R2CHADS2, CHA2DS2-VASc, R2CHA2DS2-VASc scores and AHRE ≥ or < 6 min were determined. AHRE was recorded as a heart rate > 175 bpm (Medtronic) or > 200 bpm (Biotronik) lasting ≥ 30 s. Multivariate Cox regression analysis with time-dependent covariates was used to determine the independent predictors of MACE. ROC-AUC analysis was performed for CHADS2, R2CHADS2, CHA2DS2-VASc, and R2CHA2DS2-VASc scores and then adding AHRE ≥ 6 min to the four scores. The median age was 77 years, and 107 patients (28.5%) developed AHRE ≥ 6 min. After a median follow-up of 32 months, 46 (12.2%) MACE occurred. Multivariate Cox regression analysis showed that R2CHA2DS2-VASc score (HR, 1.485; 95% CI, 1.212–1.818; p < 0.001) and AHRE ≥ 6 min (HR, 2.125; 95% CI, 1.162–3.887; p = 0.014) were independent predictors for MACE. The optimal R2CHA2DS2-VASc score cutoff value was 4.5 (set at ≥ 5), with the highest Youden index (AUC, 0.770; 95% CI, 0.709–0.831; p < 0.001). ROC-AUC analysis of the four risk scores separately combined with AHRE ≥ 6 min all showed better discriminatory power than the four scores alone (All Z-statistic p < 0.05). In patients with PPM who develop AHRE ≥ 6 min, it is crucial to perform risk assessment with either four scores to further stratify risk for MACE.

PO-03-074 INITIAL HEART RATE SCORE IS PREDICTOR FOR OCCURRENCE OF NEW ATRIAL FIBRILLATION INDEPENDENT OF WELL-KNOWN RISK FACTORS AND RELATES TO RIGHT ATRIAL PACING RATE IN PACEMAKER PATIENTS

Heart Rate Score (HRSc), the percent of right atrial (RA) beats in the largest paced or sensed 10-bpm histogram bin, predicts survival in ICD and CRT-D patients without atrial fibrillation (AF). For pacemaker (PM) patients, although age, gender and RA and right ventricular pacing percent (% RA and RV pacing) have been related to AF, the relationship of HRSc to subsequent AF is unknown. To evaluate the relationship between initial post implantation HRSc and incidence of newly developed AF, and well-known predictors for AF in PM patients. Patients with dual-chamber, atrial tracking PMs, implanted 2013-2017, who had ALTITIUDE remote monitoring data available, were included. HRSc was determined from histogram data during the first 3 months post-implant. Only patients with ≥600,000 beats of histogram data collected at baseline were included. Patients with single-chamber or biventricular PMs were excluded. Patients were excluded if they had AF, defined as atrial high rate episodes >5 minutes or >1% of RA beats >170 bpm during the initial 3-months post-implant. AF after the baseline period was evaluated by the definition: >1% of atrial beats >170 bpm. Sinus node disease (SND) was defined as needed for RA pacing ≥ 40% and atrio-ventricular block (AVB) as needed for right ventricular pacing ≥ 20% during the baseline period. Of the total population (N=34,543), 15,252 patients had device-determined SND and 16,190 patients had AVB. Utilizing multivariable analysis, the initial HRSc (HR: 1.07, 95% CI: 1.05-1.09; P<0.0001) independently predicted subsequent AF after adjusting for age, gender, % RV pacing and rate-response programming. Patients with initial HRSc≥70% were older, and had higher % RA pacing, lower % RV pacing and were more likely programmed with rate-response vs subjects with initial HRSc<70%. There was a direct, and significant, increase in new-onset AF with each 20% increment in HRSc and/or % RA pacing (both P<0.001, Figure) during median of 2.8 (1.0-4.0) years follow-up. The %RA pacing and initial HRSc were strongly correlated (Pearson correlation coefficient=0.9). % RV pacing did not predict AF. Both SND patients and AVB patients with initial HRSc≥70% had a significantly increased risk of AF (log-rank P <0.001) compared to patients with HRSc<70%. Initial HRSc, strongly related to percent RA pacing, predicts subsequent AF independent of well-known risk factors in both device-determined SND and AVB.

Galectin-3, Inflammation, and the Risk of Atrial High-Rate Episodes in Patients with Dual Chamber Pacemakers.

Atrial high-rate episodes (AHREs) are atrial tachyarrhythmias that are exclusively detected by cardiac implantable electronic devices (CIEDs) with an atrial lead. The objective of this study was to investigate the incidence and predictive factors for AHREs, and to evaluate the ability of inflammation biomarkers to predict the occurrence of AHREs. 102 patients undergoing CIED procedure who received a dual chamber pacemaker were included. CIED interrogation was performed 1 year after the implantation procedure. Patients were divided into groups according to the occurrence of AHREs, which was the primary endpoint of the study. The mean age of the patients was of 73 ± 8.6 years and 48% were male. The incidence of AHREs was 67% at 1 year follow-up. Patients with AHREs were older, had higher left atrial indexed volume (LAVi), higher baseline galectin-3 levels (1007.5 ± 447.3 vs. 790 ± 411.7 pg/mL) and received betablockers more often, along with amiodarone and anticoagulants. Interestingly, the CHADSVASC score did not differ significantly between the two groups. A cut-off value of galectin > 990 pg/mL predicted AHREs with moderate accuracy (AUC of 0.63, 95% CI 0.52 to 0.73, p = 0.04), and this association was confirmed in the univariate regression analysis (OR 1.0012, 95% CI 1.0001 to 1.0023, p = 0.0328). However, based on the multivariate regression analysis, galectin lost its prognostic significance under the effect of LAVi, which remained the only independent predictor of AHREs (OR 1.0883, 95% CI 1.0351 to 1.1441, p = 0.0009). AHREs are common in CIEDs patients. Galectin-3 may bring additional data in the prediction of AHREs.

Ability to remotely monitor atrial high-rate episodes using a single-chamber implantable cardioverter-defibrillator with a floating atrial sensing dipole.

To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend remote monitoring (RM) of device-detected atrial high-rate episodes (AHREs) and progression of arrhythmia duration along pre-specified strata (6 min…<1 h, 1 h…<24 h, ≥ 24 h). We used the MATRIX registry data to assess the capability of a single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (DX ICD system) to follow this recommendation in patients with standard indication for single-chamber ICD. In 1841 DX ICD patients with daily automatic RM transmissions, electrograms of first device-detected AHREs per patient in each duration stratum were adjudicated, and the corresponding positive predictive values (PPVs) for the detections to be true atrial arrhythmia were calculated. Moreover, the incidence and progression of new-onset AF was assessed in 1451 patients with no AF history. A total of 610 AHREs ≥6 min were adjudicated. The PPV was 95.1% (271 of 285) for episodes 6min…<1 h, 99.6% (253/254) for episodes 1 h…<24 h, 100% (71/71) for episodes ≥24 h, or 97.5% for all episodes (595/610). The incidence of new-onset AF was 8.2% (119/1451), and in 31.1% of them (37/119), new-onset AF progressed to a higher duration stratum. Nearly 80% of new-onset AF patients had high CHA2DS2-VASc stroke risk, and 70% were not on anticoagulation therapy. Age was the only significant predictor of new-onset AF. A 99.7% detection accuracy for AHRE ≥1 h in patients with DX ICD systems in combination with daily RM allows a reliable guideline-recommended screening for subclinical AF and monitoring of AF-duration progression.

Detection of Atrial High-Rate Episodes in Patients with Cardiac Implantable Electronic Devices — a Multicenter Experience from Pakistan: A Cross-Sectional Study

Objectives: Atrial high-rate episodes (AHRE) are associated with an increased risk of subclinical atrial fibrillation (SCAF) and can be identified in patients with cardiac implantable electronic devices (CIEDs). This first study from Pakistan aims to determine the incidence of AHREs and the characteristics of a Pakistani cohort with AHREs. Methodology: In this bicentric Cross-sectional study, there were 162 patients of more than 18 years with CIEDs presenting to the device clinics were enrolled. The AHREs cutoff was predefined and AHREs were documented if they last for &gt;30 seconds. Patients with known atrial fibrillation were excluded. Results: Mean age of the patients was 64.69±11.64 years and men were of 62.3%. AHREs were found in 22 (13.6%) patients out of which 13(8%) lasted more than 5 minutes. Mean AHREs cutoff 182.27±20.93. Mean CHA₂DS₂-VASc score; 3.10±1.47. 54.9% on beta-blockers, and 37% on angiotensin receptor blockers (ARB). Dual-chamber pacemaker (75.3%) and AV block (60.5%) mostly complete AV block , were the most common CIED and indication for an implant respectively. 43.8% had mildly dilated LA, only 1.2 % had severe mitral stenosis, and 3.1% had severe mitral regurgitation. Multivariable binary logistic regression analysis showed that patients on ARB had fewer episodes of AHREs (OR=0.2, 95% CI= 0.05 -0.8, P-value =0.023) while positive family history for coronary artery disease (CAD) was associated with more episodes (OR=5.62, 95% CI=1.58 -20, P-value =0.008). Conclusion: The incidence of AHREs was considerably lower in our population on CIEDs interrogation as compared to prior studies, although the CHA₂DS₂-VASc score is higher. ARB use and positive family history of CAD had a statistically significant association with AHRE occurrence.

REACT DX registry: Real world REACTion to atrial high rate episodes detected in implantable cardioverter-defibrillator recipients with a DX lead.

Atrial fibrillation (AF) is associated with significant morbidity and is predicted by atrial high rate events. The early detection of AF is paramount to timely interventions to reduce the morbidity of AF. The DX ICD system combined with Home Monitoring® allows for continuous atrial rhythm monitoring without the need for a dedicated atrial lead. To establish the reaction to and timing of reactions to the detection of atrial high rate episodes (AHRE). A prospective cohort of DX ICD systems was followed up and the response to AHREs was collected and evaluated. A total of 234 patients were enrolled; an AHRE ⩾ 6 min was detected in 13.7% of patients (n= 32) within a mean follow-up duration of 16 months. A high rate of oral anticoagulation (OAC) prescription was seen with the detection of AHREs in patients with a not-low risk CHA2DS2-VASc score. There was a delay in this prescription highlighting the potential to improve the timeliness of patient care in this group of patients. The DX ICD system provides rapid and ongoing atrial rhythm monitoring such that physicians are rapidly aware of AHRE without the need for a dedicated atrial lead, but local protocols are needed to improve the response time of anti-coagulation prescription.

Incidence and outcomes of patients with atrial high-rate episodes (AHRE) at a single, tertiary-care centre

Incidence and outcomes of patients with atrial high-rate episodes (AHRE) at a single, tertiary-care centre

Abstract 31: The ATTICUS Randomized Controlled Trial - Subgroup Analyses

Background: ATTICUS is the third prospective randomized controlled trial that compared a direct oral anticoagulant (DOAC) vs. acetylsalicylic acid (ASA) for secondary prevention after embolic stroke of undetermined source (ESUS). Aim of ATTICUS was to determine whether apixaban, initiated within 28 days after ESUS, is superior to ASA in preventing new ischemic lesions on 12-month follow- up MRI (primary endpoint) in subjects with remote atrial fibrillation (AF) monitoring. Methods: Multicenter (14 German centers) open-label randomized (1:1) controlled trial with blinded endpoint assessment. ESUS patients with at least one risk factor for AF/cardiac thromboembolism (i.e., left atrium (LA) size &gt; 45 mm, spontaneous echo contrast in LA appendage, LA appendage flow velocity ≤ 0.2 m/s, atrial high-rate episodes, CHA2DS2-VASc ≥ 4, patent foramen ovale (PFO)) were enrolled. Study drug was initiated 3 to 28 days after minor/moderate stroke and ≥ 14 to 28 days after major stroke. ClinicalTrials.gov: NCT02427126. Funding by Bristol Meyers Squibb-Pfizer Alliance (Euro 2.2 Mio.) and Medtronic. Results: 352 patients were available for final analysis. New ischemic lesion(s) were found in 13.6% vs. 16.0% of patients in the apixaban and the ASA arm, respectively (p=0.57), intention-to-treat. AF was detected in 25.6 % of patients. No difference between study arms was found for other thromboembolism, death, SAE, major and clinically relevant bleeds. Conclusions: ATTICUS was the first trial testing the concept of DOAC vs. ASA in an enriched ESUS population. Mandatory cardiac monitoring, vessel imaging, and MRI in all ATTICUS patients will help to better understand this complex condition. We will present secondary analyses including on-treatment analysis, prevention of embolic/disabling lesions/strokes, association of stroke pattern with AF occurrence/macroangiopathic changes.

Clinical Implications of Device-Detected Atrial Fibrillation in Cardiac Resynchronization Therapy.

Atrial fibrillation (AF) is associated with decreased cardiac resynchronization therapy (CRT) benefits compared to sinus rhythm (SR). Effective biventricular (BiV) pacing is a determinant of CRT success, but AF can interfere with adequate BiV pacing and affect clinical outcomes. We investigated the effect of device-detected AF on clinical outcomes and optimal BiV pacing in patients with heart failure (HF) treated with CRT. We retrospectively analyzed 174 patients who underwent CRT implantation between 2012 and 2019 at a tertiary center. The optimal BiV pacing percentage was defined as ≥98%. Device-detected AF was defined as an atrial high-rate episode ≥180 beats per minute lasting more than 6 minutes during the follow-up period. We stratified the patients without preexisting AF at pre-implantation into device-detected AF and no-AF groups. A total of 120 patients did not show preexisting AF at pre-implantation, and 54 had AF. Among these 120 patients, 19 (15.8%) showed device-detected AF during a median follow-up of 25.1 months. The proportion of optimal BiV pacing was significantly lower in the device-detected AF group than in the no-AF group (42.1% vs. 75.2%, p=0.009). The device-detected AF group had a higher incidence of HF hospitalization, cardiovascular death, and all-cause death than the no-AF group. The device-detected AF and previous AF groups showed no significant differences regarding the percentage of BiV pacing and clinical outcomes. For HF patients implanted with CRT, device-detected AF was associated with lower optimal BiV pacing and worse clinical outcomes than no-AF.

Prediction of Clinical Atrial Fibrillation by Cardiac Implantable Electronic Device detected Atrial High Rate Episodes

Prediction of Clinical Atrial Fibrillation by Cardiac Implantable Electronic Device detected Atrial High Rate Episodes

Incidence and characteristics of atrial high-rate episodes in patients with implantable cardiac devices

Incidence and characteristics of atrial high-rate episodes in patients with implantable cardiac devices

918 EARLY RECOGNITION OF SUBCLINICAL ATRIAL FIBRILLATION IN PATIENTS IMPLANTED WITH DIFFERENT DEVICES

Abstract Background Atrial fibrillation (AF) is the supra-ventricular tachyarrhythmia mostly encountered in the clinical practice.While appearing silent or with a constellation of symptoms, it confers a 5-fold risk of stroke. Early detection is mandatory to establish the diagnosis and recommend anticoagulation. Besides the arrhythmia recognition through several tools, such as Holter ECG and loop recorders, it has been underlined that cardiac implantable electronic devices with an atrial lead can help in recognizing asymptomatic AF periods, also known as atrial high-rate episodes (AHREs). Materials and Methods 48 patients with AHRE detection at device telemetry checks were enrolled; implanted device were pacemakers (n=31, 64.8%); implantable cardioverter/defibrillators (ICD, n=8, 16.6%); cardiac resynchronization therapy devices with defibrillators (CRT-D, n=9, 18.5%). Male gender was predominant (40 vs. 8), age was &amp;gt; 65years, and mean CHA2DS2VASc was 4.2±2.8. Patients underwent ECG assessment in 6-month intervals (at baseline and during follow-up), MOntreal Cognitive Assessment test, and device interrogation for AHRE of duration &amp;gt;5 minutes and rate &amp;gt;175 beats per minute. Randomization to a direct oral anticoagulant (DOAC) or usual care (aspirin when needed or placebo) was provided in a blind fashion and maintained for the entire study observation until occurrence of overt AF, followed by exclusion from the study. Results We found that 13%-16% of patients with device-detected AHRE developed AF over a mean follow-up of 2.5 year (range 4.6±2.0). These cases were given oral anticoagulation since change of indication according to current guidelines. Most important comorbidities were coronary artery disease (n=18 patients, 36.73%); systemic hypertension (n=41, 83.67%); diabetes (n=13, 26.53%); dyslipidemia (n=23, 46.8%); heart failure (n=17, 35.4%). 30 patients were treated with beta-blockers(62.5%). 2 patients died for gastrointestinal bleeding. One patient was excluded for major bleeding after one month from the enrollment. Total AHREs duration was significantly lower in patients with pacemaker (14 hrs) compared to patients with CRT-D (17 hrs) and ICD (20 hrs, p&amp;lt;0.05). Conclusions The impact of AHREs was higher in patients affected by cardiac dysfunction and concomitant diseases; none of the patients enrolled in the study developed ischemic stroke; major bleedings were observed in both arms. Further studies are warranted for considering oral anticoagulation based on the sole device interrogation in the context of subclinical atrial fibrillation.

Novel findings of an old algorithm: PVC response "Atrial Pace'' initiates atrial arrhythmias in Abbott ICD and CRT-D devices.

Many algorithms have been developed to ensure the safety and accuracy of cardiac implantable electric devices (CIED). A specific algorithm designed to prevent pacemaker induced tachycardia (PMT) after a premature ventricular complex (PVC response) is available in all Abbott (former St. Jude Medical) CIED. However, a few case reports suggest that this algorithm may be proarrhythmic when programmed to Atrial Pace (A-Pace on PVC). We analyzed the data of all (n=333) Abbot implantable cardioverter defibrillator (ICD) and cardiac resynchronization defibrillator (CRT-D) devices followed remote using the Merlin.net Patient Care Network in our institute in 2020. Status of the PVC response algorithm A-Pace on PVC or Off was collected, and all atrial mode switch (AMS) episodes longer than 30 s were thoroughly evaluated. Data on clinical characteristics of the patients was collect from the electronic patient records. A total of 173 patients had A-Pace on PVC and twenty-five of them (14%) had at least one atrial high rate episode (AHRE) >30 s (AHRE) triggered by the action of this algorithm. The median PVC count was higher in patients who had algorithm triggered AHRE than in those with no algorithm-triggered AHRE (1.7% [IQR 0-3.2] vs. 0% [IQR 0-1.1], p<.0001). The major clinical characteristics were comparable in the two groups. The A-Pace on PVC setting was frequently used in our patients. Our study shows that a considerable number of patients had at least one AHRE triggered by the algorithm. The use of this algorithm should be carefully reconsidered.

When to set anticoagulant therapy in asymptomatic AF? looking for a cut-off duration.

The incidence of atrial fibrillation (AF) is progressively increasing, in line with the aging of the population and with the increase in chronic diseases. The care burden of the disease and above all to its consequences (i.e. ischaemic stroke and heart failure) significantly impacts the various health systems with forecasts of exponential increase in the near future. Clinical forms of AF, i.e. those diagnosed with electrocardiogram, have a clear correlation with systemic embolic events and also with a reduction in survival. Thromboembolic prophylaxis in these patients, with anticoagulant drugs, has in fact been shown to greatly reduce the incidence of ischaemic stroke and improve survival. In recent decades, the widespread use of therapeutic intra-cardiac devices, which allow constant and continuous monitoring of myocardial electrical activity, is bringing to light a large number of atrial high rate episodes (AHREs), which are not associated with clinical manifestation. The incidence of these findings grows linearly with the duration of the observation. More independent studies have shown that AHREs are associated with a risk of stroke that is higher (about double) than controls but significantly lower than in patients with manifest AF. However, taking into consideration patients with ischaemic stroke and wearers of implantable devices, no temporal correlation emerged between the incidence of the ischaemic episode and arrhythmia. The presence of AHRE is associated with an approximately six-fold increase in the incidence of clinical AF but only a minority of these patients meet the criteria for prescribing anticoagulation. Pending the publication of the studies still in progress, the European Society of Cardiology guidelines for the treatment of AF recommend considering the initiation of anticoagulant therapy in patients with long-lasting AHRE (> 24 h) associated with a high embolic risk. In patients with episodes of shorter duration (1-24 h), especially if with high burden, anticoagulant therapy can be considered in case of very high embolic risk (e.g. secondary prevention, CHADVASc ≥ 3).

Incidence of atrial high rate episodes after dual-chamber permanent pacemaker implantation and its clinical predictors

Atrial high rate episodes (AHRE) confers increased morbidity and mortality amongst patients with permanent pacemaker implantation (PPI). The incidence of AHREs and it's clinical predictors in Indian patients without prior history of atrial fibrillation (AF) are not well understood. A total of 100 dual-chamber PPI patients, who had no prior history of AF, underwent pacemaker interrogation starting from a minimum of 1 month after implantation to detect any AHREs. The incidence of AHREs was 17% at a mean follow up 15.2 ± 7.5 months. Only right ventricular apical lead position was found to have an independent association with AHREs (OR: 3.50, 95% CI: 1.02–12.03; p = 0.04).

Multimodality imaging assessment of the Biatrial remodeling of the burden of atrial high-rate episodes in patients with cardiac implanted electronic devices

AimsThe underlying mechanisms of atrial remodeling in cardiac implanted electronic device(CIED)-detected atrial high-rate episodes(AHRE) remains to be elucidated. MethodsA cardiac computed tomography and a strain echocardiography were performed to delineate the structural and functional characteristics of both atria. Biatrial volumes, emptying fraction(EF) and peak atrial longitudinal/contractile strain(PALS/PACS) were evaluated. All AHRE were analyzed. ResultsA total of 80 CIED patients with AHRE were categorized by AHRE duration into 3 groups: Group 1: <6 min(n = 42), Group 2: 6 min ∼ 6 h(n = 23), and Group 3: >6 h(n = 15). Left atrial(LA) maximal volume(Vmax), atrial precontraction volume(Vapc), minimal volume(Vmin), LAEF, and PALS/PACS were all increasingly worsened among the patients in the 3 groups (p value for trend <0.05).Compared to Group 1, Group 2 had decreased LA PALS/PACS. There was no significant difference in LA volume or EF between Group 1 and 2. Group 3 had enlarged biatrial volumes (LAVmax: 57.1(SD 16.0) vs. 45.4(SD 9.2) mL/m2, p = 0.002; LAVmin: 42.6(SD 18.2) vs. 28.2(SD 7.2) mL/m2, p < 0.001), impaired total LAEF (28.0(SD 13.7) vs. 38.2(SD 7.7)%, p = 0.004) and reduced PALS/PACS compared to Group 1. Atrial remodeling in those with AHRE >6 h had increased LA volumes, impaired LAEF and reduced PALS/PACS compared to those with AHRE <6 h. ConclusionFunctional remodeling of the atria manifested after AHRE >6 min. Increased biatrial volumes and decreased LA reservoir and pump function occurred when AHRE were > 6 h. These LA structural and functional may be considered surrogate imaging markers for stroke risk assessment in patients with CHA2DS2-VASc ≥2 and AHRE.

Cardiac variables associated with atrial fibrillation occurrence and mortality in octogenarians implanted with dual chamber permanent pacemakers.

There is a dearth of data on the predictors of atrial fibrillation (AF) and the association between AF and long-term mortality in octogenarians with dual-chamber permanent pacemakers (PPM). We investigate the occurrence of AF and whether it is associated with overall mortality among octogenarians with dual-chamber PPM implants. Three hundred and fifty-four patients with PPM implants were divided into two groups based on their long-term survival status. Baseline characteristics, laboratory variables, and echocardiographic variables were then compared between the groups, and independent predictors of the long-term incidence of AF and mortality were determined. Multivariable Cox regression analysis performed after adjusting for the parameters in univariable analysis revealed that diabetes, urea levels, albumin levels, paced QRS duration, and the frequency of atrial high-rate episodes (AHREs) were independently associated with a long-term risk of AF in octogenarians after having dual chamber PPMs implanted. The left ventricular (LV) ejection fraction, left atrial (LA) anteroposterior diameter, and AHRE + AF (HR 1.498, 95%CI 1.003-2.237, p = 0.048) were independent risk factors for the long-term mortality in octogenarians receiving dual-chamber PPMs implants. The occurrence of AF following dual-chamber PPM implantation is a significant prognostic factor in octogenarian patients.