Atrial High-rate Episodes Research Articles

Effects of sodium-glucose cotransporter-2 inhibitor on atrial high-rate episodes in patients with cardiovascular implantable electronic device: a randomized controlled trial

Effects of sodium-glucose cotransporter-2 inhibitor on atrial high-rate episodes in patients with cardiovascular implantable electronic device: a randomized controlled trial

Oral Anticoagulation in Device Patients With Atrial High-Rate Episodes: Shared Decision-Making After ARTESIA and NOAH-AFNET-6.

Oral Anticoagulation in Device Patients With Atrial High-Rate Episodes: Shared Decision-Making After ARTESIA and NOAH-AFNET-6.

Incidence of silent brain injury in pacemaker implanted patients with atrial high-speed episodes (AHRE)

Abstract Purpose Atrial high rate episodes (AHRE) are tachyarrhythmia attacks that can be detected by implantable cardiac devices. In the European Society of Cardiology (ESC) 2020 AF guideline, AHRE is defined as ≥ 175 bpm for the device-programmed rate criterion and ≥ 5 minutes for the duration criterion. AHRE has been shown to be one of the predisposing factors of AF and stroke. However, the relationship between AHRE and SBI has not been clarified yet. Neuron spesific enolase (NSE) is a valid biomarker for quantifying the volume of neuronal damage. In this study, we aimed to evaluate the incidence of silent brain injury (SBI), defined as elevated NSE levels in AHRE detected patients. Method Between January 2021 and June 2022, 80 patients who underwent routine pacemaker control, met the inclusion and exclusion criteria, and had AHRE detected in their permanent pacemaker records were included in a university faculty of medicine cardiology arrhythmia polyclinic. For the control group, patients who had a permanent pacemaker and did not have AHRE or any other arrhythmia were included. Of patients with AHRE detected in the last 6 months and those who had an AHRE attack within the last 72 hours were examined. Results Individuals included in the study were divided into subgroups according to AHRE duration. Group 1 (non-AHRE) 80 (50.0%), Group 2 (AHRE lasting <5 min) 24 (15.0%), Group 3 (≥5 min - <1h) 33 (20.6%), 19 (11.9%) patients in Group 4 (lasting ≥1 h - <24 h) and 4 (2.5%) patients in Group 5 (lasting ≥24 h). There was a statistically significant difference in NSE median values between groups (p=<0.001). In Mann Whitney U test with Bonferronni correction, the median values of all other groups were significantly different from each other (p=<0.001). In the correlational analysis, there was a statistically significant positive relationship between AHRE duration and NSE values (r=0.842; p=<0.001). Additionally, there was correlation between AHRE duration and age (r=0.235; p=0.036), CHA2DS2-VASc score (r=0.226, p=0.044) and LA diameter (r=0.300; p=0.007). NSE levels were positively correlated with AHRE duration (r=0.842; p=<0.001) and LA diameter (r=0.242; p=0.030). Conclusion AHRE duration was longer in patients with advanced age, increased CHA2DS2-VASc score, and increased LA diameter. This may play a role in explaining the underlying pathophysiological changes in AHRE before AF develops. Since NSE levels are related to LA diameter as well as AHRE duration, it can be thought that increasing LA diameter contributes to the development of thrombus.

The role of anticoagulation in atrial high-rate episodes: a meta-analysis

Abstract Background The role of anticoagulation in patients with atrial high-rate episodes (AHRE), who have no prior history of atrial fibrillation or atrial flutter, is being extensively studied. Purpose Given the increased thrombo-embolic risk in patients who have atrial high-rate episodes, our aim was to evaluate whether anticoagulation leads to enhanced clinical outcomes compared to no anticoagulation (1). Methods We searched PubMed, EMBASE, and the Cochrane Library, through February 2024, for studies evaluating outcomes in patients with atrial high-rate episodes managed with oral anticoagulation (OAC) compared to those not managed with oral anticoagulation. Outcomes assessed were ischemic stroke, thromboembolic events, major bleeding, and all-cause mortality. A fixed-effects model was used to calculate pooled risk risk ratios (RR) and their 95% confidence intervals (CI). Results A total of 4 studies comprising 6788 patients were included. Anticoagulation was associated with a significant reduction in the risks of ischemic stroke (RR 0.66; 95% CI 0.49 - 0.90; P = 0.0084) and thromboembolic events (RR 0.70; 95% CI 0.55 - 0.89; P = 0.0037). Compared to atrial high-rate episodes not managed with anticoagulation, there was a significantly increased risk of major bleeding with anticoagulation (RR 1.57; 95% CI 1.23 - 2.00; P = 0.0002), while the risk of all-cause mortality was similar (RR 1.07; 95% CI 0.95 - 1.21; P = 0.2437). Conclusion Our study suggests that anticoagulation in patients with atrial high-rate episodes decreases the risks of ischemic stroke and thromboembolic events, while increasing the risk of major bleeding, compared patients not managed with anticoagulation. Our study does not show a mortality benefit with the use of anticoagulation in patients with atrial high-rate episodes. Further studies are needed to confirm the safety and efficacy of anticoagulation in atrial high-rate episodes.Forest Plots of Outcomes Assessed

Clinical outcomes of atrial high-rate episodes: an updated meta-analysis

Abstract Background Atrial high-rate episodes (AHRE) are commonly detected in individuals with cardiac implantable electronic devices. Outcomes of atrial high-rate episodes remain unclear in those without a prior history of atrial fibrillation. Purpose This study aims to evaluate clinical outcomes of atrial high-rate episodes in patients who have no prior history of atrial fibrillation. Methods PubMed, EMBASE, and Cochrane databases were searched through February 2024 for studies evaluating clinical outcomes in individuals with cardiac implantable electronic devices who experienced atrial high-rate episodes, compared to those who did not. Individuals who had a prior history of atrial fibrillation were excluded. Outcomes assessed were clinical atrial fibrillation, thromboembolic events, and all-cause mortality. A fixed-effects model was used to calculate risk ratios (RRs) with 95% confidence intervals (CI). A subgroup analysis of thromboembolic events was conducted based on the duration of atrial high-rate episodes. Results A total of 9 studies met inclusion criteria with a combined enrollment of 7440 patients. Compared to those who did not experience atrial high-rate episodes, those who did had significantly increased risks of clinical atrial fibrillation (RR 3.33; 95% CI 1.99 - 5.57; P < 0.0001) and thromboembolic events (RR 2.21; 95% CI 1.72 -2.85; P < 0.0001). The risk of all-cause mortality was similar between both groups (RR 1.19; 95% CI 0.95 – 1.49; P = 0.13). Subgroup analysis revealed an increased risk of thromboembolic events among atrial high-rate episodes ≥ 24 hours (RR 12.34; 95% CI 2.70 – 56.36) while atrial high-rate episodes lasting < 24 hours were insignificantly associated with thromboembolic events (RR 0.83; 95% CI 0.12 – 5.58). Conclusions Our study indicates a heightened risk of clinical atrial fibrillation and thromboembolic events among patients with atrial high-rate episodes, with no observed increase in mortality risk. Furthermore, our findings suggest that the duration of atrial high-rate episodes influences the risk of thromboembolism. Further studies are warranted to confirm our findings.

Identifying at-risk patients for atrial high-rate episodes by machine learning

Abstract Background Current evidence suggests that atrial high rate episodes (AHRE)/subclinical atrial fibrillation (AF) are associated with increasing risk of clinical AF, and subsequently, ischaemic stroke and other adverse cardiovascular events. Purpose To construct a high-performance model by machine learning (ML) for the prediction of AHRE detected by a cardiac implantable electronic device (CIED) capable of atrial sensing in a European cohort. Methods We utilized data from a prospective cohort of patients with CIED. AHRE was defined as an episode lasting at least 5 minutes with atrial rate ≥ 175 beats per minute. We divided the cohort into training and internal validation cohorts in 7:3 and used 5-fold cross-validation in the training cohort to assess model performance and prevent model overfitting. Pre-selected features were imported into eight common ML algorithms to predict AHRE, including light gradient boosting machine (LightGBM), random forest (RF), logistic regression, support vector machine, multiple perceptron, eXtreme gradient boosting machine (XGBoost), Gaussian naïve Bayes, and K nearest neighbours. The importance ranking of the features was interpreted by calculating the SHapley Additive exPlanationation (SHAP) value for each feature within the optimal model. Results A total of 500 consecutive patients with CIEDs (mean age 70.2±13.3; 39.2% female) were included. Of these, 164 patients (32.8%) were found to have AHRE. Among all ML models, RF was the best performing model, which obtained the highest AUC (0.738), recall (0.673) and F1-score (0.584) in the internal validation cohort. The results of SHAP showed that antiplatelet, statin, age, white blood cell count, and cardiomyopathy were the first five important features, indicating that the RF model had good interpretability and reliability. Conclusion Our study is the first to demonstrate in a European cohort the effectiveness and feasibility of ML algorithms in predicting AHRE in patients detected by CIEDs. The best RF models require further external validation to assess generalizability to other cohorts.Figure 1Figure 2

Study of right atrial and right ventricular function in dual chamber pacemaker patients

Abstract Background Unlike left ventricular function, right ventricular (RV) function in pacemaker patients is less well studied with less studies comparing septal versus apical pacing effects on the RV function and almost none on the right atrial (RA) function. Purpose To assess the effect of RV pacing on the echocardiographic and clinical parameters of the RV and RA function and their correlation with the site of right ventricular lead implantation. Methods The study assessed 59 patients in need of permanent dual chamber pacemaker implantation using clinical and echocardiographic data of the RV and RA size and function using tricuspid annular plane systolic excursion (TAPSE), S wave velocity of the tricuspid annulus and fractional area change (FAC), free wall strain (FWSL), global longitudinal strain (GLS) of the RV, RA strain including reservoir, conduit and contraction phases and 3D ejection fraction of the RV using Epiq 7 Ultrasound machine (Philips Healthcare) by the same echocardiographer before implantation and 6 months after. All programming parameters were recorded postoperative and 6 months later. Results 31 patients had the RV lead in the RV apex whereas 28 had it in the septum and all patients had their RA lead in the right atrial appendage, with no significant difference between both groups regarding baseline demographic, clinical nor echocardiographic data. At 6 months, there was a significant decline of the 3D RVEF from a mean of (58.57% ± 6.35%) to (56.41% ± 6.17%), TAPSE from (2.61 cm ± 0.51) to (2.35 cm ± 0.52) and S wave from (13.73 cm/sec ± 2.84) to (12.64 cm/sec ± 2.61) but none showed a significant difference between septal and apical pacing, on the other hand, the RV strain showed a significant decline 6 months after implantation in both the FWSL from (-31.75% ± 5.39) to (-27.82% ± 5.73) and the GLS from (-25.89% ± 5.17) to (-21.65% ± 4.51) with more decline in the septal group compared to the apical (-20.33% ± 4.70 versus -22.84% ± 4.04 regarding the GLS and -26.11% ± 6.41 versus -29.37% ± 4.62 in the FWSL, respectively). There was no difference in the FAC, tricuspid regurgitation severity, gradient nor the estimated pulmonary artery pressure at 6 months. The RA size showed a significant decline at 6 months but no difference in any of the strain parameters. No clinical RV failure symptoms nor signs were observed. Programming revealed a mean percentage of ventricular pacing of (97.92% ± 2.67%) with a minimum of 91% and atrial pacing of (10.41% ± 12.52%), and the thresholds, impedance and atrial high-rate episodes were comparable postoperatively and 6 months after, with no difference between the septal and apical groups. Conclusion At 6 months follow-up after pacemaker implantation, right ventricular function starts to show decline in both the septal and apical groups with only the right ventricular strain more affected in the septal group compared to the apical.3D right ventricular ejection fraction3D right ventricular strain

Impact of atrial high-rate episodes on new onset of atrial fibrillation and all-cause mortality in elderly patients over 90 years old with dual-chamber pacemaker implantation

Objective: To investigate the impacts of atrial high-rate episodes (AHRE) on the risks of new onset of atrial fibrillation and all-cause mortality in elderly patients over 90 years old after cardiac dual-chamber pacemaker implantation. Methods: This study was a retrospective study. Patients aged 90 years and above who were implanted with cardiac dual-chamber pacemakers and followed up in the People's Liberation Army General Hospital from January 2017 to June 2022 were enrolled and divided into AHRE≥6 h group and AHRE<6 h group according to the onset time of AHRE. The primary endpoint was new onset of atrial fibrillation, and the secondary endpoints were all-cause mortality and cardiovascular mortality. Kaplan-Meier survival curve was poltted, and log-rank test was used to compare the differences in the incidence of new onset of atrial fibrillation, all-cause death and cardiovascular death between AHRE≥6 h and AHRE<6 h groups. Multivariate Cox survival analysis was used to investigate the factors affecting new onset of atrial fibrillation, all-cause death and cardiovascular death in elderly patients aged 90 years and above with dual-chamber pacemaker implantation. Results: A total of 169 patients were enrolled, aged (93.95±3.28) years, including 18 females (11%). The median follow-up time was 28.9 months. There were 87 and 82 patients in AHRE≥6 h group and AHRE<6 h group, respectively. Kaplan-Meier survival curve analysis showed that the incidence of new onset of atrial fibrillation (log-rank P<0.001), all-cause death (log-rank P=0.004) and cardiovascular death (log-rank P=0.026) in AHRE≥6 h group was significantly higher than that in AHRE<6 h group.After adjusting for traditional risk factors, multivariate Cox survival analysis showed that AHRE≥6 h was an independent risk factor for new onset of atrial fibrillation (HR=4.046, 95%CI 2.402-6.814, P<0.001) and all-cause mortality (HR=1.668, 95%CI 1.119-2.487, P=0.012) in elderly patients over 90 years old with cardiac dual-chamber pacemaker implantation. However, AHRE≥6 h had no effect on cardiovascular mortality (P>0.05). Anemia (HR=3.098, 95%CI 1.342-7.153, P=0.008) and heart failure with reduced ejection fraction (HR=3.028, 95%CI 1.181-7.763, P=0.021) were both independently associated with cardiovascular mortality. Conclusions: AHRE is common in cardiac dual-chamber pacemakers recipients aged 90 years and above, and AHRE≥6 h can be used as a predictor of new onset of atrial fibrillation or all-cause mortality in these patients.

Association Between P-Wave Duration, Dispersion, and Interatrial Block and Atrial High-Rate Episodes in CIED Patients.

Atrial high-rate episodes (AHRE) have been linked to increased thromboembolic risk and all-cause mortality in patients with cardiac implantable electronic devices (CIEDs). Various predictors of AHRE development have been identified, emphasizing the need for close monitoring and the potential transition to clinical atrial fibrillation (AF). However, the predictive value of P wave characteristics on AHRE development remains conflicting. This meta-analysis aims to summarize existing data to investigate this association. We examined studies from MEDLINE and EMBASE databases up to May 2024 to investigate the association of baseline P-wave duration (PWD), P-wave dispersion (PWDIS), and interatrial block (IAB) with the risk of developing AHRE. We extracted the mean and standard deviations of PWD and PWDIS to calculate the pooled mean difference (MD). Risk ratios (RR) and 95% confidence intervals (CIs) were used to assess the association between IAB and AHRE risk, using the generic inverse variance method for combination. The meta-analysis included nine studies. Patients with AHRE had longer PWD and PWDIS compared to those without AHRE, with a pooled MD for PWD of 9.17ms (95% CI: 4.74-13.60; I2 = 47%, p < 0.001) and a pooled MD for PWDIS of 20.56ms (95% CI: 11.57-29.56; I2 = 57%, p < 0.001). Additionally, patients with IAB had a higher risk of developing AHRE, with a pooled RR of 3.33 (95% CI: 2.53-4.38; I2 = 0%, p < 0.001), compared to those without IAB. Our meta-analysis found that patients with AHRE had higher PWD and PWDIS than those without AHRE. Additionally, IAB was associated with a higher risk of developing AHRE. These findings emphasize the importance of close monitoring and risk stratification, particularly for patients with P wave abnormalities.

Incidence and Clinical Predictors of Atrial Fibrillation in Patients with Dual-Chamber Pacemakers: A Retrospective Analysis

Abstract Atrial fibrillation (AF) is a prevalent cardiac arrhythmia, affecting millions worldwide and increasing in frequency with age. Despite progress in treatment and prevention, AF remains a significant contributor to stroke, heart failure, and overall cardiovascular morbidity. One particularly challenging type of AF, paroxysmal atrial fibrillation (PAF), is often asymptomatic, leading to delayed diagnosis and increasing the risk of severe complications like stroke. The advent of cardiac implantable electronic devices (CIEDs) has significantly improved the ability to detect subclinical AF or atrial high-rate episodes (AHRE), even in patients with no symptoms. These devices, particularly pacemakers, offer long-term, continuous monitoring of atrial rhythms, making them an invaluable tool for diagnosing AF early and assessing its burden in real time. This study focused on a cohort of patients from the Oltenia region who received dual-chamber pacemakers with no prior diagnosis of AF. The research aimed to monitor the incidence of AF in these patients over a follow-up period of 12 to 18 months and to identify potential clinical predictors for developing AF. A total of 91 patients were assessed in this study, all of whom received dual-chamber pacemakers by the pacing guidelines for conditions such as atrioventricular block and sick sinus syndrome. None of the patients had a history of AF at the time of implantation. Follow-up results indicated an incidence of AHRE in 13.19% of patients, with significant predictors including advanced age and the presence of hypertension. These findings align with the broader literature, which consistently associates both factors with an increased risk of AF. The study underscores the importance of continuous monitoring in pacemaker patients, particularly for detecting asymptomatic AF, which may necessitate specific therapeutic interventions. Although the study’s sample size was limited, its findings contribute valuable insights into managing AF in pacemaker patients, particularly regarding early detection and potential risk factors. Future research with larger cohorts is necessary to confirm and expand these results.

The incidence and risk factors of atrial high‐rate episodes in patients with a dual‐chamber pacemaker

AbstractBackground and ObjectivesCardiovascular implantable electronic devices can detect atrial high‐rate episodes (AHREs). However, the predictors of clinically relevant AHREs have not been well identified.MethodsThis prospective study included 145 patients (median age 64.5 ± 16.4 years, 53.1% females) without atrial fibrillation (AF) from December 2020 to January 2022. AHREs were defined as a programmed atrial detection rate &gt;190 beats per minute. Cox regression analysis was used to identify the risk factors of AHREs.ResultsDuring 6 months of follow‐up, AHREs occurred in 30.3% of patients. Multivariable Cox regression analysis showed factors related to development of AHREs including using anti‐arrhythmic drugs (AAD) before implantation (Hazard ratio (HR) 7.71; 95% confidence interval [95% CI], 2.58–23.02, p &lt; .001), history of paroxysmal supraventricular tachycardia (PSVT; HR 2.45; [95% CI], 1.18–5.09, p = .016), the percentage of premature atrial contraction (PAC) on 24‐h Holter electrocardiogram (ECG) monitoring (HR 1.008; [95% CI], 1.003–1.014, p = .003), and left ventricular global longitudinal strain (GLS‐LV; HR 0.92;[95% CI], 0.84–0.99, p = .049).ConclusionsThis study showed that a history of PSVT and using AAD, the percentage of PAC on 24‐h Holter ECG monitoring, and GLS‐LV were the independent predictors of new‐onset AHREs.

Management of Device Detected Subclinical Atrial Fibrillation

Abstract Purpose of Review Whilst the management of clinically apparent atrial fibrillation (AF) is well-described and evidenced, the same is not true for subclinical atrial fibrillation (SCAF) and atrial high rate episodes (AHRE). In this review article we discuss the management of device-detected AHRE/SCAF in light of recent major trials and meta-analyses. Recent Findings Anticoagulation in AHRE/SCAF reduces thromboembolic risk but causes an increase in bleeding events. Of note, ischaemic stroke risk in untreated AHRE/SCAF has been observed to be lesser than that of untreated clinically evident AF. With regard to reduction of AHRE/SCAF prevalence or burden, increased physical activity has been associated with reduced AHRE/SCAF incidence in a dose-dependent manner. There exists mixed evidence for both angiotensin 2 inhibition therapy and statin therapy in the prevention of AHRE/SCAF in studies with smaller populations. Ongoing studies are assessing the impact of sodium-glucose cotransporter-2 inhibition on AHRE/SCAF. Although there is no evidence for atrial overdrive pacing in preventing AHRE/SCAF, limited evidence suggests pacing lead position and reducing ventricular pacing may minimise AHRE/SCAF. Summary The identification of AHRE/SCAF poses unanswered questions regarding treatment. The benefit of anticoagulation in reducing ischaemic stroke is lesser than that seen in clinical AF. As such, anticoagulation decisions in AHRE/SCAF should take into consideration individual bleeding risk, thromboembolic risk, and arrythmia burden. Management of co-morbidities and physical activity show promise in reducing AHRE/SCAF. Further study is required to investigate the impact of various pharmacologic interventions and pacing considerations on the reduction of AHRE/SCAF.

Anticoagulation in Patients With Device-Detected Atrial Fibrillation With and Without a Prior Stroke or Transient Ischemic Attack: The NOAH-AFNET 6 Trial.

Short and rare episodes of atrial fibrillation (AF) are commonly detected using implanted devices (device-detected AF) in patients with prior stroke or transient ischemic attack (TIA). The effectiveness and safety of oral anticoagulation in patients with prior stroke or TIA and device-detected AF but with no ECG-documented AF is unclear. This prespecified analysis of the NOAH-AFNET 6 (Non-Vitamin K Antagonist Oral Anticoagulants in Patients With Atrial High Rate Episodes) trial with post hoc elements assessed the effect of oral anticoagulation in patients with device-detected AF with and without a prior stroke or TIA in the randomized, double-blind, double-dummy NOAH-AFNET 6 trial. Outcomes were stroke, systemic embolism, and cardiovascular death (primary outcome) and major bleeding and death (safety outcome). A prior stroke or TIA was found in 253 patients with device-detected AF randomized in the NOAH-AFNET 6 (mean age, 78 years; 36.4% women). There was no treatment interaction with prior stroke or TIA for any of the primary and secondary time-to-event outcomes. In patients with a prior stroke or TIA, 14 out of 122 patients experienced a primary outcome event with anticoagulation (5.7% per patient-year). Without anticoagulation, there were 16 out of 131 patients with an event (6.3% per patient-year). The rate of stroke was lower than expected (anticoagulation: 4 out of 122 [1.6% per patient-year]; no anticoagulation: 6 out of 131 [2.3% per patient-year]). Numerically, there were more major bleeding events with anticoagulation in patients with prior stroke or TIA (8 out of 122 patients) than without anticoagulation (2 out of 131 patients). Anticoagulation appears to have ambiguous effects in patients with device-detected AF and a prior stroke or TIA in this hypothesis-generating analysis of the NOAH-AFNET 6 in the absence of ECG-documented AF, partially due to a low rate of stroke without anticoagulation.

Atrial High-Rate Episodes and Subclinical Atrial Fibrillation: State of the Art and Clinical Questions with Complex Solutions.

Atrial high-rate episodes (AHREs) and subclinical atrial fibrillation (AF) are frequently registered in asymptomatic patients with cardiac implantable electronic devices (CIEDs) and insertable cardiac monitors (ICMs). While an increased risk of thromboembolic events (e.g., stroke) and benefits from anticoagulation have been widely assessed in the setting of clinical AF, concerns persist about optimal clinical management of subclinical AF/AHREs. As a matter of fact, an optimal threshold of subclinical episodes' duration to predict stroke risk is still lacking and recently published randomized clinical trials assessing the impact of anticoagulation on thromboembolic events in this specific setting have shown contrasting results. The aim of this review is to summarize current evidence regarding classification and clinical impact of subclinical AF/AHREs and to discuss the latest evidence regarding the potential benefit of anticoagulation in this setting, highlighting which clinical questions are still unanswered.

Controversies in Diagnosis and Management of Atrial Fibrillation.

Early detection of atrial fibrillation (AF) plays an important role in decreasing adverse cardiovascular outcomes. It is estimated, however, that one-third of those with AF are asymptomatic and may experience the adverse effects of the arrhythmia prior to being detected clinically. In the past, AF was diagnosed on 12-lead electrocardiogram or medically prescribed external monitors. The development of device-monitoring technologies capable of recording AF or AF-surrogates such as atrial high-rate episodes on cardiovascular implantable electronic devices or photoplethysmography/electrocardiogram on consumer-grade wearable devices, has resulted in increased recognition of device-detected, subclinical, AF. Recent studies reveal information about the stroke risk associated with these subclinical events and the response to anticoagulation and raise important questions about the use of both medical and direct-to-consumer AF detection devices for screening purposes. In addition to screening and detection of AF, emerging studies are also being conducted on different strategies for maintenance of sinus rhythm and stroke prevention including catheter ablation and left atrial appendage occlusion. This review aims to highlight recent developments and future studies in these areas.

Closed loop stimulation reduces the incidence of atrial high-rate episodes compared with conventional rate-adaptive pacing in patients with sinus node dysfunctions.

Subclinical atrial fibrillation (AF) is associated with increased risk of progression to clinical AF, stroke, and cardiovascular death. We hypothesized that in pacemaker patients requiring dual-chamber rate-adaptive (DDDR) pacing, closed loop stimulation (CLS) integrated into the circulatory control system through intra-cardiac impedance monitoring would reduce the occurrence of atrial high-rate episodes (AHREs) compared with conventional DDDR pacing. Patients with sinus node dysfunctions (SNDs) and an implanted pacemaker or defibrillator were randomly allocated to dual-chamber CLS (n = 612) or accelerometer-based DDDR pacing (n = 598) and followed for 3 years. The primary endpoint was time to the composite endpoint of the first AHRE lasting ≥6 min, stroke, or transient ischaemic attack (TIA). All AHREs were independently adjudicated using intra-cardiac electrograms. The incidence of the primary endpoint was lower in the CLS arm (50.6%) than in the DDDR arm (55.7%), primarily due to the reduction in AHREs lasting between 6 h and 7 days. Unadjusted site-stratified hazard ratio (HR) for CLS vs. DDDR was 0.84 [95% confidence interval (CI), 0.72-0.99; P = 0.035]. After adjusting for CHA2DS2-VASc score, the HR remained 0.84 (95% CI, 0.71-0.99; P = 0.033). In subgroup analyses of AHRE incidence, the incremental benefit of CLS was greatest in patients without atrioventricular block (HR, 0.77; P = 0.008) and in patients without AF history (HR, 0.73; P = 0.009). The contribution of stroke/TIA to the primary endpoint (1.3%) was low and not statistically different between study arms. Dual-chamber CLS in patients with SND is associated with a significantly lower AHRE incidence than conventional DDDR pacing.

New-onset atrial high-rate episodes in left bundle branch area pacing versus right ventricular pacing for patients with atrioventricular block.

Left bundle branch area pacing (LBBAP) demonstrated beneficial effects on clinical outcomes. Comparative data on the risk of atrial high-rate episodes (AHREs) between LBBAP and right ventricular pacing (RVP) are lacking. This study aimed to investigate whether LBBAP can reduce the risk of new-onset AHREs compared with RVP in patients with atrioventricular block (AVB). We enrolled 175 consecutive AVB patients with no history of atrial fibrillation undergoing dual-chamber pacemaker implantation (LBBAP or RVP). Propensity score matching for baseline characteristics yielded 43 matched pairs. The primary outcome was new-onset AHREs detected on a scheduled device follow-up. Changes in echocardiographic measurements were also compared between the groups. New-onset AHREs occurred in 42 (24.0%) of all enrolled patients (follow-up 14.1 [7.5] months) and the incidence of new-onset AHREs in the LBBAP group was lower than in the RVP group (19.8% vs. 34.7%; P = 0.04). After propensity score matching, LBBAP still resulted in a lower incidence of new-onset AHREs (11.6% vs. 32.6%; P = 0.02), and a lower hazard ratio for new-onset AHREs compared with RVP (HR, 0.274; 95% CI, 0.113-0.692). At 1 year, LBBAP achieved preserved left ventricular ejection fraction (LVEF) (63.0 [3.2]% to 63.1 [3.1]%; P = 0.56), while RVP resulted in reduced LVEF (63.4 [4.9]% to 60.5 [7.3]%; P = 0.01]). Changes in LVEF were significantly different between the 2 groups (by 2.6% [0.2 to 5.0]%; P = 0.03). LBBAP demonstrated a reduced risk of new-onset AHREs compared with RVP in patients with AVB.

Atrial High-Rate Episodes in Elderly Patients: The Anticoagulation Therapy Dilemma.

Atrial fibrillation (AF) has been associated with higher morbidity and mortality rates, especially in older patients. Subclinical atrial fibrillation (SCAF) is defined as the presence of atrial high-rate episodes (AHREs) > 190 bpm for 10 consecutive beats > 6 min and <24 h, as detected by cardiac implanted electronic devices (CIEDs). The selection of eligible patients for anticoagulation therapy among elderly individuals with AHREs detected through CIEDs remains a contentious issue. The meta-analysis of ARTESiA and NOAH-AFNET 6 clinical trials revealed that taking Edoxaban or Apixaban as oral anticoagulation therapy can reduce the risk of stroke by approximately 32% while increasing the risk of major bleeding by approximately 62%. However, it is still unclear which are, among patients with SCAF, those who can take the highest net clinical benefit from anticoagulant therapy. The present review summarizes the current evidence on this intriguing issue and suggests strategies to try to better stratify the risk of stroke and systemic embolism in patients with AHREs. We propose incorporating some parameters including chronic kidney disease (CKD), obesity, enlarged left atrial volume, the efficacy in blood pressure management, and frailty into the traditional CHA2DS2-VASc score. Future trials will be needed to verify the clinical usefulness of the proposed prognostic score mainly in the view of a personalized therapeutic approach in patients with SCAF.

Pacemaker-induced atrial fibrillation reconsidered-associations with different pacing sites and prevention approaches.

The incidence of atrial fibrillation (AF) is significantly higher in patients with pacemakers than in the general population, which could be due to patient characteristics and the diagnostic tool of the pacemaker in detecting atrial high-rate episodes and subclinical AF, but also to the pacemaker itself providing AF-promoting conditions. It is well known that high ventricular pacemaker burden increases the likelihood of AF occurrence. However, the sites of atrial and ventricular pacing may also influence the risk for AF. The conventional sites for atrial and ventricular pacing are in the right atrial appendage and in the right ventricular apex. However, growing evidence suggests that alternative pacing sites may be superior for the prevention of AF. Bachmann bundle pacing, for example, promotes interatrial excitation conduction, resulting in atrial synchronicity and a shorter total atrial activation time, which may be preventive for the occurrence of AF. Moreover, in recent years, new ventricular pacing sites have come into focus with His bundle and left bundle branch pacing. In addition to the hemodynamic and electrophysiological cardiac benefits, these new options may also offer benefits in the prevention of AF. This review provides an overview of pacing-induced AF mechanisms and the association with different pacing sites, as well as approaches for prevention of pacing-induced AF, highlighting different sites and modes of atrial pacing and the newer sites of ventricular pacing.

Outcomes of Device-detected Atrial High-rate Episodes in Patients with No Prior History of Atrial Fibrillation: A Systematic Review and Meta-analysis.

Outcomes of device-detected AF remain unclear in individuals without a prior history of AF. A meta-analysis was conducted to evaluate outcomes in individuals with no prior history of AF who experienced device-detected AF. Outcomes assessed were clinical AF, thromboembolism and all-cause mortality. A fixed-effects model was used to calculate RRs with 95% CI. Compared to individuals who did not experience device-detected AF, those who did had increased risks of clinical AF (RR 3.33, 95% CI [1.99.5.57]; p<0.0001) and thromboembolic events (RR 2.21; 95% CI [1.72.2.85]; p<0.0001). The risk of all-cause mortality was similar between both groups (RR 1.19; 95% CI [0.95.1.49]; p=0.13). Subgroup analysis revealed an increased risk of thromboembolic events among device-detected AF .24 hours (RR 12.34; 95% CI [2.70.56.36]). While there is an increased risk of clinical AF and thromboembolism in individuals with device-detected AF, mortality was insignificant.