AF Episodes Research Articles

Heart rate variability to predict 1-day atrial fibrillation episode onset using machine learning

Abstract Background Studies using AI assessment of 10-second 12-lead ECG suggest that it provides incremental identification of AF risk compared with clinical scores. However, it is not clear what preventive treatment should be given as the exact time of AF onset remains unknown. The use of machine learning (ML) with 2-lead Holter ECG allows the development of predictive models for paroxysmal AF within a short time window, potentially allowing an optimised pill-in-the-pocket (PITP)-like strategy. Aim To identify patients who are still in sinus rhythm but will develop an episode of AF in the next few hours using 24-hour Holter recordings and ML. Materials and methods We created a new database of 95871 Holter recordings that were manually analysed. We identified 1319 paroxysmal AF episodes from 872 patients. A total of 835 AF episodes from 506 recordings had more than 60 minutes of normal sinus rhythm (NSR) before AF onset and more than 10 minutes of AF after onset, and a total of 964 AF episodes had 30 minutes or more of NSR before AF onset. Patients were divided into five groups: all patients, patients younger than 60 years, 60-70 years, 70-80 years, and older than 80 years. A total of 365 recordings from 347 patients without rhythm abnormalities were identified and classified in our database, from which we took two ECG windows. We used a gradient-boosted decision tree model with heart rate variability (HRV) parameters as input. Results The most significant results were obtained from recordings with more than 5 minutes of AF with an AUROC of 0.919 (95% CI: 0.879-0.958) and an AUPRC of 0.919 (0.879-0.958) 15H08 ± 13H05 hours before the onset of AF (Figures 1 - 2). Using a threshold of 0.5, the accuracy was 84.5% (81.2-87.8), the sensitivity was 83.0% (79.5-86.4), the specificity was 86.6% (79.3-93.9), the PPV was 90.2% (85.5-94.9), the NPV was 78.4% (74.7-82.1) and the F1 score was 86.2% (83.5-89.0) for all patients. Conclusion These results suggest that the most important information for short-term prediction of AF onset is contained in HRV, allowing a preventive strategy. This could be exploited by wearables in mHealth allowing the use of a PITP-like preventive strategy to reduce the burden of AF. Prospective studies are needed to confirm the encouraging potential of these findings.AUROC of the XGBoost modelPrecision-recall curves

Impact of obesity and early recurrence of atrial fibrillation on very late recurrence following cryoballoon pulmonary vein isolation

Abstract Background Obesity and early recurrence of atrial fibrillation (ERAF) post cryoballoon (CB) pulmonary vein isolation (PVI) both portend a lower 1-year success rate of ablation. Even after an initial successful ablation, about 1/3 of patients develop a very late recurrence (VLR) of AF, defined as the first AF recurrence more than a year after ablation (excluding an initial 90 day blanking period [BP]). The impact of obesity and ERAF on VLR is still unknown. Purpose To evaluate the impact of obesity and ERAF on VLR following CB PVI. Methods We enrolled consecutive patients with symptomatic AF who underwent CB PVI and had an implantable loop recorder for long-term ECG monitoring. We identified patients who had no AF recurrence (outside the BP) in the first-year post ablation. ERAF was defined as any episode of AF recorded in the first 90 days post ablation. Patients were grouped as either obese (BMI ≥ 30 kg/m2) or non-obese (BMI <30 kg/ m2). AF recurrences after 1-year post-ablation were ascertained using the loop recorder. Results From the initial cohort of 210 patients, 109 (52%) patients (64 ± 10 years; 75 [68%] male; 64 [59%] PAF; CHA2DS2-VASc 2.3 ± 1.4, 38 [35%] with obesity and 41 [38%] had ERAF) were AF-free during the first year. During a follow-up of 961 ± 196 days, 51 (47%) patients had VLR. Non-obese patients without ERAF had the best outcome (Figure). In multivariate analysis, obesity and ERAF were the only significant predictors of VLR (Table). As compared to non-obese patients without ERAF, obese patients with ERAF had a 4-fold greater likelihood of VLR. Conclusions About 50% of patients have no AF recurrence in the first year after CB PVI. Non-obese patients have the best outcome regardless of ERAF occurrence. On the other hand, obese patients with ERAF almost always have VLR.

Cognitive behavioral therapy for symptomatic paroxysmal atrial fibrillation: effects on physical activity, sleep and heart rate variability

Abstract Background We have devised a novel psychological intervention, cognitive behavioral therapy for paroxysmal atrial fibrillation (AF-CBT), that targets symptom preoccupation and avoidance behaviour. AF-CBT significantly improved cardiac anxiety and quality of life (QoL) in a randomized trial. To what extent this may be attributed to changes in physiological parameters is yet to be determined. Purpose A) to assess changes in objective and subjective measures of physical activity and sleep. B) to evaluate potential treatment effects on heart rate variability (HRV). Methods Patients with paroxysmal AF on optimal medical therapy (65.4±8.3 years, 58% women) and European Heart Rhythm Association Symptom Score ≥2b were randomized to a 10-week therapist-led online AF-CBT (n=65) or a control group (n=62), with the primary outcome of Atrial Fibrillation Effect on Quality-of-life (AFEQT). A Patch-Holter with an integrated accelerometer was applied for five days at baseline, post-treatment, and at three months follow-up. Each recording was divided into day and night (sleep time) based on posture, heart rate, and activity. HRV was analysed in both time and frequency domains, excluding AF episodes and aberrant beats. Results AFEQT increased from 62.4±14.3 to 83.7± 13.8 points in the AF-CBT group at the 3-month follow-up with a relative difference of 15.0 points. At baseline, the participants walked 8040±2600 steps/day and slept 8.0 ± 1.1 hours. AF-CBT did not increase physical activity, and there were no significant changes in objective sleep duration. The Insomnia Severity Score went from subclinical (12.2±6.7) to near normal values (8.1±5.6), which was significant as compared to controls (p=0.032). AF burden increased from 5.3% to 7.3% in the AF-CBT group and 5.0% to 9.2% in the control group, with no difference between the groups (p=0.59). We did not observe any change in heart rate or HRV indices at rest during the day or at night. Conclusion AF-CBT did not mediate its effects on QoL by improving objective physiological variables. Thus, our findings underline the importance of subjective, psychological, and behavioural aspects and indicate that AF-CBT might fill a void beyond medical and lifestyle interventions in comprehensive AF care.

Characterization of Post Coronary Artery Bypass Grafting Atrial Fibrillation Patterns (CABG-AF): Rationale and Design of an Investigator-Initiated Observational Study

New-onset postoperative atrial fibrillation (POAF) after cardiac surgery is associated with increased rates of adverse events (including mortality and stroke). Its incidence after coronary artery bypass grafting (CABG) is considered to be approximately 30 % and it is thought to be a transient condition. However, studies investigating POAF after CABG fail to provide appropriate data on incidence and arrhythmia patterns due to the use of intermittent rhythm detection strategies. These methods have a low sensitivity as compared to continuous monitoring. Subsequently, studies utilizing these techniques most likely do not identify all patients with arrhythmia and do not adequately demonstrate the long-term incidence of arrhythmia, which in turn may affect its association with adverse events. The CABG-AF study (German Clinical Trials Register Nr.: DRKS00018887) tests the hypothesis that the incidence of AF in the first 12 months after CABG is significantly underestimated. CABG-AF is an investigator-initiated multicenter, prospective, observational study in which 196 patients with no history of arrhythmia undergoing first-time CABG, receive an insertable cardiac monitor for continuous postoperative rhythm monitoring. The primary endpoint of the study is any episode of AF within the first 12 months after surgery. Secondary endpoints include AF burden, AF density and the ratio of silent to symptomatic AF episodes. Endpoints will be investigated by automatic and patient-initiated data transfers from the implanted device, by telephone interview of patients and by follow-up forms sent to patients by mail. The patients will be followed for a planned follow-up of 3 years. In conclusion, the CABG-AF study will provide information on the true incidence of AF after CABG as well as on the temporal patterns of the arrhythmia.

"Real-world" performance of the Confirm Rx™ SharpSense AF detection algorithm: UK Confirm Rx study.

The novel Confirm Rx™ implantable cardiac monitor (ICM) with SharpSense™ technology incorporates a new P-wave discriminator designed to improve AF detection. This study aimed to evaluate the diagnostic performance of the Confirm Rx™ ICM in detecting AF episodes of varying durations. We conducted a multicenter retrospective analysis of consecutive patients implanted with a Confirm Rx™ ICM (v1.2) across nine UK hospitals, all with documented AF lasting at least 6 min. Electrocardiograms (ECGs) were manually adjudicated by cardiologists. To account for intra- and inter-reviewer variability, a random sample of 10% of ECGs underwent additional review. Disagreements were resolved by a third reviewer. Diagnostic performance was determined by calculating the gross and patient-averaged positive predictive value (PPV) for AF episodes of different duration. The source of false positive (FP) detection was also categorized. Overall, 16,230 individual ECGs from 232 patients were included. The median AF episode duration was 14 min. R-wave amplitude remained stable during follow-up (0.52 ± 0.27 mV [initial] vs. 0.54 ± 0.29 mV [end of follow-up], p = .10). The gross and patient-averaged PPV were 75.0% and 67.0%, respectively. Diagnostic performance (gross) increased with progressively longer AF episodes: 88.0% for ≥1 h, 97.3% for 6 h, and 100% for 24 h. The main source of FP during tachycardia was T-wave oversensing (54.2%), while in non-tachycardic episodes it was predominantly ectopy (71.2%). The AF burden precision was excellent (93.3%). The Confirm Rx™ ICM diagnostic performance was modest for all AF episodes (75%), with accuracy increasing for longer AF episodes.

Incidence of All-Cause, Cardiovascular, and Atrial Fibrillation-Related Hospitalizations: Focus on Antiarrhythmic Drugs

BackgroundAtrial fibrillation (AF) is associated with an increased risk of hospital admission, but few data on reasons for hospitalization and on the role of anti-arrhythmic drugs are available. ObjectivesThe purpose of this study was to investigate the incidence rate and factors associated with all-cause, cardiovascular, and AF-related hospitalizations. MethodsProspective ongoing ATHERO-AF (Atherosclerosis in Atrial Fibrillation) cohort study enrolling AF patients on oral anticoagulants. Primary end points were all-cause, cardiovascular, and AF-related hospitalization, the latter defined as AF recurrences for paroxysmal AF and high-rate symptomatic AF episodes for persistent/permanent AF patients. Results2,782 patients were included (43.5% female; mean age was 74.6 ± 9.1 years). During a mean follow-up of 31 ± 26.8 months, 1,205 (12.1%/year) all-cause, 533 cardiac (5.7%/year), and 180 (2.0%/year) AF-related hospitalizations occurred. Predictors of AF-related hospitalizations were the use of flecainide/propafenone in both paroxysmal and persistent/permanent AF patients (HR: 1.861; 95% CI: 1.116 to 3.101 and 1.947; 95% CI: 1.069 to 3.548, respectively). Amiodarone (HR: 3.012; 95% CI: 1.835-4.943), verapamil/diltiazem (HR: 2.067; 95% CI: 1.117-3.825), and cancer (HR: 1.802; 95% CI: 1.057-3.070) but not beta-blockers and digoxin were associated with an increased risk of AF-related hospitalizations in persistent/permanent AF patients. ConclusionsElderly AF patients frequently undergo hospitalizations for both cardiovascular and noncardiovascular causes. The use of anti-arrhythmic drugs was associated with an increased risk of AF-related hospitalization suggesting a scarce effect of these drugs in preventing AF episodes. Therefore, their use should be carefully considered and reserved for symptomatic patients with frequent AF recurrences.

Detection of atrial fibrillation using a nonlinear Lorenz Scattergram and deep learning in primary care

BackgroundAtrial fibrillation (AF) is highly correlated with heart failure, stroke and death. Screening increases AF detection and facilitates the early adoption of comprehensive intervention. Long-term wearable devices have become increasingly popular for AF screening in primary care. However, interpreting data obtained by long-term wearable ECG devices is a problem in primary care. To diagnose the disease quickly and accurately, we aimed to build AF episode detection model based on a nonlinear Lorenz scattergram (LS) and deep learning.MethodsThe MIT-BIH Normal Sinus Rhythm Database, MIT-BIH Arrhythmia Database and the Long-Term AF Database were extracted to construct the MIT-BIH Ambulatory Electrocardiograph (MIT-BIH AE) dataset. We converted the long-term ECG into a two-dimensional LSs. The LSs from MIT-BIH AE dataset was randomly divided into training and internal validation sets in a 9:1 ratio, which was used to develop and internally validated model. We built a MOBILE-SCREEN-AF (MS-AF) dataset from a single-lead wearable ECG device in primary care for external validation. Performance was quantified using a confusion matrix and standard classification metrics.ResultsDuring the evaluation of model performance based on the LS, the sensitivity, specificity and accuracy of the model in diagnosing AF were 0.992, 0.973, and 0.983 in the internal validation set respectively. In the external validation set, these metrics were 0.989, 0.956, and 0.967, respectively. Furthermore, when evaluating the model’s performance based on ECG records in the MS-AF dataset, the sensitivity, specificity and accuracy of model diagnosis paroxysmal AF were 1.000, 0.870 and 0.876 respectively, and 0.927, 1.000 and 0.973 for the persistent AF.ConclusionsThe model based on the nonlinear LS and deep learning has high accuracy, making it promising for AF screening in primary care. It has potential for generalization and practical application.

Automated continuous rhythm monitoring with implantable cardiac monitor and real-time smartphone alerts during af episodes: SMART-ALERT study

Abstract Introduction The 'Pill-in-the-pocket' oral anticoagulation (OAC) strategy is based upon the concept of dynamic thromboembolic risk which increases during and shortly after an atrial fibrillation (AF) episode. Limiting OAC use in low-risk patients with infrequent AF may offer comparable stroke protection and reduce bleeding. However, this approach relies on precise continuous rhythm monitoring with real-time alerts to patients. LINQ II implantable cardiac monitor transmits regularly to Carelink via smartphone app, but lacks patient alerts. To address this limitation, we developed bespoke software that triages transmissions in Carelink and sends alerts via SMS to patients. Purpose This feasibility study evaluates the precision of the LINQ II in detecting AF and assesses the efficacy of bespoke software in delivering 'real-time' SMS alerts to participants' smartphones, and measures compliance with these alerts. Methods In this single-center feasibility study, individuals with frequent AF episodes underwent LINQII implantation. The bespoke software, operating in the cloud, systematically reviewed all Carelink transmissions at 5-min intervals. SMS alerts were triggered based on specific criteria: 1)AF >30 min; 2)only the initial AF episode >30 min within a 24h period was transmitted; and 3)AF episodes uploaded or detected after a 24h delay were disregarded. Participants confirmed receipt of the alert by responding to the SMS, and timestamps for these interactions were recorded in a database (Fig. 1). Results A total of 50 patients were prospectively enrolled, and LINQ II was implanted. The median age was 49 years, 62% male, 90% had paroxysmal AF. Over a 3-month mean follow-up, 4080 AF episodes >30 min occurred in 32 patients. Among these, 700 met the criteria for triggering an alert, with 72.14% sent to patients within 24 h. Alerts were not transmitted for 3 main reasons: smartphone failure to transmit to Carelink within a 24 h period, software issues connecting to Carelink (website maintenance), and updates in the webservers. The median time from an AF episode to the transmission of SMS alerts was 2.47 h, with 85.54% of alerts being sent within 12 hours. Once an SMS was sent, the median time for acknowledgment was 4.3 min. The median time from an AF episode to acknowledgment was 4.23 h (Fig. 2). Notably, 97.62% of episodes were acknowledged within 24 hours. Patients failed to acknowledge an SMS alert on only 3 occasions. Conclusions Safely delivering 'pill-in-the-pocket' OAC requires a closed-loop system where devices provide real-time alerts during during AF , thus minimising delays in initiating OAC. This feasibility study establishes that the integration of bespoke software with LINQ II exhibits promising efficacy with a high percentage of SMS alerts within 24 hours, exceptional patient compliance, and a median response time of only 4.3 min. Nonetheless, further efforts are needed for seamless integration with Carelink to enhance connectivity.

Clinical characteristics and genetic substrate of lone atrial fibrillation: a single center experience

Abstract Background Juvenile-onset lone atrial fibrillation (LAF) may be the initial manifestation of a concealed channelopathy or cardiomyopathy (CMP) or it may be due to an atrial specific genetic susceptibility. Clinical characteristics, genetic background and proper management are still largely unknown. Purpose Aim of the present study is to describe the clinical and genetic characteristics of patients with juvenile-onset LAF. Methods We enrolled patients referred to our center for ablation between 1/2018 and 11/2023 with a first diagnosis of LAF before the age of 60, a structurally normal heart (absence of known CMP, ischemic, valvular, congenital heart disease) and no overt channelopathy. A concealed Brugada syndrome was systematically excluded. Genetic testing was performed using Next Genome Sequencing and a dedicated gene panel. Results 89 patients were included (84% male, LAF onset 43 ± 8 years, BMI 25 ± 7 kg/m2): 32% had a first-degree family history of AF (including 15% below 60 years), 18% of sudden death, 8% of cardiac conduction disorders and 2% of CMP. Cardiovascular risk factors included arterial hypertension in 24%, smoking in 47% and obstructive sleep apnea syndrome in 4%; 20% were competitive athletes. Most patients (89%) presented with paroxysmal AF and 92% were symptomatic (mainly palpitations). At presentation LVEF was 61±5% and LAVI 35±14 ml/m2. Median follow-up time after the first AF episode was 6 years (IQR 4-10). Most patients (81, 91%) underwent at least one transcatheter ablation procedure after failed anti-arrhythmic drug (AAD) therapy (mostly IC). The first procedure (73% radiofrequency, 27% cryoablation) included pulmonary veins isolation (PVI) in all and additional lesions in 5%; the second procedure (n=18, 22% of the ablation group) included PV re-isolation in all (mostly due to multiple vein reconnections) and additional lesions in 17%; the third procedure (n=8, 10% of the ablation group) included PV re-isolation in 25% and additional lesions in 75%. The remaining 8 patients were treated with AAD only (mostly IC). By the last follow-up, 7% of patients in the ablation group and 25% in the AAD group had documented recurrences (even though 50% of those who received ablation were still on AAD). Among the 35 patients subjected to genetic investigation, 10 have available results: 30% tested positive for C4-C5 variants (2 for KCNQ1, 1 for TTN), 50% for C3 variants (RYR2, ABCC9, LMNA, KCNH2 and RMB20) and 20% were negative. Conclusions In the present single center cohort of patients with juvenile-onset LAF, a positive family history was found in almost one third of patients. Despite prompt diagnosis and treatment (including >1 ablation in 20% of patients), recurrences rate is not trivial. The yield of genetic test so far is high, supporting its use in this population.

Postoperative atrial fibrillation burden and progression patterns after cardiac surgery during 2.5 years of continuous rhythm monitoring

Abstract Background Early postoperative atrial fibrillation (POAF) is a frequent complication after cardiac surgery, with an incidence of up to 50%.(1, 2) The clinical presentation of early-POAF, however, might be highly diverse, showing great individual differences in symptoms, as well as POAF-specific characteristics such as the number of episodes, duration of episodes, and the percentage of time spent in POAF (POAF-burden). It is currently unknown how these early-POAF characteristics, particularly POAF-burden, are related to the risk of developing late-POAF recurrences. Purpose To establish the association between early-POAF characteristics, in particular POAF-burden, and late-POAF occurrence and burden. Methods Patients with and without a history of AF undergoing cardiac surgery were included. Preoperatively, all patients underwent echocardiography, electrocardiography, and blood biomarker analysis. Intraoperatively, all patients received an implantable loop recorder for a period of 2.5 years. POAF was defined as an AF episode lasting at least 2 minutes, detected by the ILR algorithm, and all episodes were manually checked by the investigators. POAF-burden was calculated as the percentage of time in AF for different time intervals (early: 0-3 months, late: 3-30 months). Classification of burden was performed based on cut-off values for tertiles. Also, associations between early-POAF characteristics, such as episode duration, and the incidence of late-POAF were analyzed. Results The study population consisted of 98 patients undergoing cardiac surgery (71 without preoperative AF history and 27 with preoperative AF history), out of which 53 developed POAF. Early-POAF occurred in 46 patients, and late-POAF in 36 patients. Early-POAF was associated with an increased occurrence of late POAF after adjusting for age, sex, PAF-history, and persistent AF-history (adjusted hazard ratio [aHR] = 4.62, 95% CI: 1.93-11.05, p<0.001) (Figure 1A). Multiple regression analysis, adjusted for age, sex, PAF-history, and persistent AF-history, revealed a gradual increase in late-POAF hazard between the early-POAF burden tertiles compared to patients without early-POAF (p<0.001) (Figure 1B). Similarly, the longest individual early-POAF episode and the number of early-POAF episodes were both associated with an increased late-POAF hazard (p<0.001 and p<0.001, respectively) (Figure 1C-D). The highest POAF-burden was observed in the early postoperative phase, with a significant reduction in the late phase (p=0.007) (Figure 2A). Overall, 84 patients had no late-POAF or a reduction in POAF burden, while 14 patients showed an increase in POAF-burden compared to the early postoperative phase (Figure 2B). Conclusion Early-POAF characteristics, such as POAF-burden, are strongly associated with an increased occurrence of late-POAF. The highest POAF-burden is present in the early postoperative phase, and only a minority of patients experience an increase in late-POAF burden.Figure 1Figure 2

Temporal association between atrial fibrillation and ischemic stroke: Systematic review and meta-analysis.

Paroxysmal atrial fibrillation (PAF) is strongly associated with ischemic stroke. Continuous cardiac implantable electronic devices (CIEDs) can assess PAF episodes over prolonged periods. Studies that attempted to find a temporal association between PAF and ischemic stroke were inconclusive. Thus, we performed a systematic review and meta-analysis to assess this relationship. This study aimed to assess the temporal association between AF episodes and stroke within 30 days of the arrhythmic episode. The secondary outcome is a temporal association within a 90-day period. A total of 2804 studies that discussed the temporal relationship between PAF and ischemic stroke were screened, and 7 studies were included in the meta-analysis. Among the 4041 patients included in these studies, there were 138 patients with device detected PAF episodes and stroke. Four studies used a 30-day window for temporality and the pooled odds ratio (OR) showed a significant association (OR 4.11 (95% CI 1.03-16.40)). The three studies reporting on AF and stroke within a 90-day window did not find a significant temporal relationship (OR 0.43 (95% CI 0.13-1.41)). Finally, the pooled result of those seven studies did not show a significant association (OR 1.51 (95% CI 0.44-5.17)). This meta-analysis supports a temporal relationship between PAF and ischemic stroke within a 30-day window. Establishing this relationship is important for individualized risk prediction and targeted anticoagulation treatment. The data will be made available upon reasonable request.

Pulmonary vein isolation combined with a new protocol of linear ablation to treat persistent atrial fibrillation: a prospective cohort with 1 year follow-up

Abstract Background The clinical value of ablation strategies beyond pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (perFA) is not clearly established and the optimal strategy to cure perFA remains a challenge due to the high recurrence rate after PVI alone (up to 50% of patients during 1-year follow-up). Purpose To determine the additional therapeutic value of a new design of linear ablation in the left atrium (LA) added to PVI in patients with perFA. Methods In this prospective study consecutive patients with perFA were included and underwent PVI combined with a predefined homogeneous protocol of linear ablation in the LA: anterolateral line from the mitral annulus to the left superior pulmonary vein around the left atrial appendage, anteroseptal line and posterior wall isolation. Patients were followed during 12 months after ablation with daily 30 s single-lead ECG obtained with mobile applications. The main endpoint was the incidence of recurrences, defined as any documented, sustained (>30 s) episodes of atrial arrhythmia that occurred after a 3 months blanking period. Antiarrhythmic drugs were avoided after the blanking period. Results 59 patients were included (61 [IQR 53-69] years old, 76% male sex). Acutely successful PVI was achieved in all patients and the linear ablation protocol was performed in 52 (89,7%) patients. The linea ablation protocol was not completed in 6 patients due to the following reasons: repetitive AF triggering from the same PV in 2 patients, induction and successful focal ablation of left atrial flutter in 1 patient, respiratory failure in 1 patient with severe obstructive lung disease and excessively prolonged procedure time in 2 patients. 58 patients completed the 12 months follow-up period and 1 patient was lost due to end-stage heart failure. The survival free of atrial arrhythmia recurrences was 69.1% [95%CI 55.1-79.5] (Figure). No patient had recurrences of perAF (>7 days continuous AF). 9 (53%) patients had at least 1 episode of self-limited paroxysmal AF. In these patients the average paroxysmal AF burden during the follow-up was 24 hours/year [IQR 9-24 hours/year]. In another 8 (47%) patients the recurrent arrhythmia was atypical left atrial flutter exclusively The incidence of procedure-related complications was 6,9%: 1 pericardial bleeding, 1 acute pulmonary edema, 1 splenic infarction and 1 stroke); no patient died during the study period. Conclusions A combined strategy of PVI plus the specific linear ablation protocol used in this study is associated with a low rate of atrial arrhythmia recurrences and total absence of persistent AF after ablation. A randomized multicenter clinical trial is ongoing to validate these results.Ablation strategy.Kaplan-Meier curve: recurrences

Atrial fibrillation recurrence in oncocardiological patients treated with catheter ablation. A retrospective cohort study

Abstract Background The relationship between oncological events and cardiovascular pathologies is a subject still widely discussed. Certain chemotherapy drugs, including alkylating agents, anthracyclines, taxanes, and topoisomerase II inhibitors have proven to possess arrhythmic and cardiotoxic capabilities. There is enough evidence to suggest an association between oncological events and the appearance of newly onset AF, but there is little to no scientific literature about the management of these patients and the outcome of normal therapeutically procedures. Purpose This study assess if oncocardiological patients with AF should be considered a risk group when planning to undergo catheter ablation for the arrhythmia treatment. Methods The studied population was based on the data recollection from the electrophysiology department and consisted of patients with AF intervened by radiofrequency catheter ablation. All the procedures were conducted between January 1st 2019 and December 31st 2022. Among 138 participants enrolled for this study, 68 of them had either recent history of oncological events (maximum of 5 years cancer-free). The control group had no previous nor active history of cancer. The cohort with the desired exposure (cancer patients) was compared with a cancer-free group. Two primary outcomes were measured: procedure related complications, and first AF recurrence within the first 12 months. Complications were categorized according to two dichotomous variables: the existence of acute complications directly during the procedure or within the first 12 hours after the end of the procedure, and the occurrence of self-limited arrhythmic events during the blanking period. Results When compared as dichotomous variables (yes/no) with Fisher’s exact test, no statistical significance was observed between the studied cohort and control for complications and events during blanking. The proportion of patients free of sustained episodes of AF at 12 months was 52,9% in the oncologic group and 77,9% in the Control group (P = 0.003; RR of 3.14; 95% CI 1.5 - 6.6) for the oncologic group. When not adjusted by any other factor, association with Cancer was shown (HR 2.43; P =0.005; 95% CI 1.3 – 4.4) for recurrence of arrhythmic events. The regression model with Kaplan-Meier method shows the overall 12-month survival in two groups and the difference between the two survival curves was statistically significant (P=0.0016). Conclusion Oncocardiological patients have demonstrated a significantly higher incidence in post-ablational recurrence when compared with a similar cancer-free control group. Results found in acute and chronic procedural complications were similar in both cohorts.

A Simple Score for Predicting Paroxysmal Atrial Fibrillation in Patients with Embolic Stroke of Undetermined Source in a Tunisian Cohort Study.

The annualized recurrent stroke rate in patients with Embolic Stroke of Undetermined Source (ESUS) under antiplatelet therapy is around 4.5%. Only a fraction of these patients will develop atrial fibrillation (FA), to which a stroke can be attributed retrospectively. The challenge is to identify patients at risk of occult AF during follow-up. This work aims to determine clinical factors and electrocardiographic and ultrasound parameters that can predict occult AF in patients with ESUS and build a simple predictive score applicable worldwide. This is a single-center, registry-based retrospective study conducted at the stroke unit of Sahloul University Hospital, Sousse, Tunisia, between January 2016 and December 2020. Consecutive patients meeting ESUS criteria were monitored for a minimum of one year, with a standardized follow-up consisting of outpatient visits, including ECG every three months and a new 24-hour Holter monitoring in case of palpitations. We performed multivariate stepwise regression to identify predictors of new paroxysmal AF among initial clinical, electrocardiographic (ECG and 24-hour Holter monitoring) and echocardiographic parameters. The coefficient of each independent covariate of the fitted multivariable model was used to generate an integerbased point-scoring system. Three hundred patients met the criteria for ESUS. Among them, 42 (14%) patients showed at least one episode of paroxysmal AF during a median follow-up of two years. In univariate analysis, age, gender, coronary artery disease, history of ischemic stroke, higher NIHSS at admission and lower NIHSS at discharge, abnormal P-wave axis, prolonged P-wave duration, premature atrial contractions (PAC) frequency of more than 500/24 hours, and left atrial (LA) mean area of more than 20 cm2 were associated with the risk of occurrence of paroxysmal AF. We proposed an AF predictive score based on (1.771 x NIHSS score at admission) + (10.015 x P-wave dispersion; coded 1 if yes and 0 if no) + (9.841x PAC class; coded 1 if ≥500 and 0 if no) + (9.828x LA class surface; coded 1 if ≥20 and 0 if no) + (0.548xNIHSS score at discharge) + 0.004. A score of ≥33 had a sensitivity of 76% and a specificity of 93%. In this cohort of patients with ESUS, NIHSS at both admission and discharge, Pwave dispersion, PAC≥500/24h on a 24-hour Holter monitoring, and LA surface area≥20 cm2 provide a simple AF predictive score with very reasonable sensitivity and specificity and is applicable almost worldwide. An external validation of this score is ongoing.

Recurrence of Atrial Fibrillation in Patients With New-Onset Postoperative Atrial Fibrillation After Coronary Artery Bypass Grafting

New-onset postoperative atrial fibrillation (POAF) occurs in approximately 30% of patients undergoing coronary artery bypass grafting (CABG). It is unknown whether early recurrence is associated with worse outcomes. To test the hypothesis that early AF recurrence in patients with POAF after CABG is associated with worse outcomes. This Swedish nationwide cohort study used prospectively collected data from the SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry and 3 other mandatory national registries. The study included patients who underwent isolated first-time CABG between January 1, 2007, and December 31, 2020, and developed POAF. Data analysis was performed between March 6 and September 16, 2023. Early AF recurrence defined as an episode of AF leading to hospital care within 3 months after discharge. The primary outcome was all-cause mortality. Secondary outcomes included ischemic stroke, any thromboembolism, heart failure hospitalization, and major bleeding within 2 years after discharge. The groups were compared with multivariable Cox regression models, with early AF recurrence as a time-dependent covariate. The hypothesis tested was formulated after data collection. Of the 35 329 patients identified, 10 609 (30.0%) developed POAF after CABG and were included in this study. Their median age was 71 (IQR, 66-76) years. The median follow-up was 7.1 (IQR, 2.9-9.0) years, and most patients (81.6%) were men. Early AF recurrence occurred in 6.7% of patients. Event rates (95% CIs) per 100 patient-years with vs without early AF recurrence were 2.21 (1.49-3.24) vs 2.03 (1.83-2.25) for all-cause mortality, 3.94 (2.92-5.28) vs 2.79 (2.56-3.05) for heart failure hospitalization, and 3.97 (2.95-5.30) vs 2.74 (2.51-2.99) for major bleeding. No association between early AF recurrence and all-cause mortality was observed (adjusted hazard ratio [AHR], 1.17 [95% CI, 0.80-1.74]; P = .41). In exploratory analyses, there was an association with heart failure hospitalization (AHR, 1.80 [95% CI, 1.32-2.45]; P = .001) and major bleeding (AHR, 1.92 [1.42-2.61]; P < .001). In this cohort study of early AF recurrence after POAF in patients who underwent CABG, no association was found between early AF recurrence and all-cause mortality. Exploratory analyses showed associations between AF recurrence and heart failure hospitalization, oral anticoagulation, and major bleeding.

Isolation of the superior vena cava by ultra-low temperature cryoablation.

A patient with shocks from his ICD related to AF underwent redo ablation. The only identifiable target was the superior vena cava. This was isolated using ultra-low cryotherapy, eliminating episodes of AF.

Very-early detection of atrial fibrillation after ablation evaluated by a wearable ECG-patch predicts late blanking period recurrence: Preliminary data from a prospective registry

IntroductionAtrial fibrillation (AF) ablation represents a safe and effective procedure to restore sinus rhythm. The idea that post-procedural AF episodes - during theblanking period-are not considered treatment failure has been increasingly challenged. The E-Patch, a single-use adhesive electrode, facilitates extended continuous ECG monitoring for 120 h. This pilot study aims to assess the effectiveness of this ambulatory monitoring device and investigate whether very-early AF recurrence correlates with delayed blanking period ablation outcomes. MethodsWe conducted a single-center, prospective, longitudinal study, including consecutive post-ablation patients monitored with the E-patch. The ability of the device to continuously record was analyzed, as well as the occurrence of AF episodes during external 7-day loop-recorder in the 2nd-month post-ablation. ResultsWe included 40 patients, median age 62 years (IQR 56–70). E-Patch monitoring was obtained for a median of 118 h (IQR 112–120), with no discomfort nor interpretation artefacts. Very-early AF recurrence was detected in 11 (27.5 %) patients, with a median AF burden of 7 % (IQR 6 %–33 %). Late-blanking period AF was detected in 13 (33 %) of theexternal 7-day looprecordings.Of the 11 patients that had very-early AF recurrence, 10 (91 %) had late-blanking AF. Very-early AF detectionshowed77 % (95 % CI 64 %-90 %) sensitivityand 96 % (95 % CI 90–100 %) specificity inpredictinglate-blanking AF, with a non-parametric ROCcurve AUC of 0.903 (95 % 0.797––1.0). ConclusionThe E-Patch was able to detect very-early AF during an extended period. Very-early AF detection emerges as a predictor of AF recurrence during the late blanking period post-ablation.

New-onset postoperative atrial fibrillation following coronary artery bypass grafting: Incidence, clinical course and short-term outcomes

The aims of this retrospective study were to investigate the incidence, clinical course and short term outcomes of new-onset postoperative atrial fibrillation (POAF) following coronary artery bypass surgery (CABG). A nation-wide study on 1622 patients who underwent CABG from 2006-2020 at Landspitali University Hospital. Clinical data were extracted from registries and 121 patients with pre-existing AF excluded, leaving 1501 patients for further analysis. Patient charts and postoperative ECGs were manually reviewed for determining details of POAF, which was defined as a postoperative episode of AF before discharge lasting at least 5 minutes. Patients with POAF (n=483) were compared to non-POAF patients (n=1018). Altogether 483 (32.2%) patients developed POAF; the annual incidence decreasing over time (tau= -0,45, p=0.023). Most patients were diagnosed on the second day postoperatively (43.5%) and over 90% were diagnosed within 4 days. The median number of POAF episodes was 3 (IQR: 1-5), the first episode lasting 1-6 hours in half of the cases and the total POAF-duration being 12 hours median (IQR: 5-30). Over 94% of cases converted to sinus rythm before discharge, with 25 (5.3%) patients being discharged in AF. Most patients were treated with beta-blockers (98.8%), amiodarone (95%) and 14.9% with electric cardioversion. POAF-patients were older, had higher EuroSCORE II and a longer hospital stay, however, they had similar rates of early postoperative stroke and 30 day mortality. The incidence of POAF remains high and was associated with prolonged hospital stay, but not significantly higher 30 day mortality or early postoperative stroke compared to patients in sinus rhythm. POAF-episodes were predominantly transient and almost 95% of patients were discharged in sinus rythm.

Is there a temporal relationship between atrial fibrillation and stroke? A review

ImportanceAtrial fibrillation (AF) is an established risk factor for ischaemic stroke. The introduction of continuous cardiac rhythm monitoring devices has enabled detection of brief and asymptomatic episodes of AF.ObservationsThe search...

Atrial fibrillation and survival on a medical intensive care unit

BackgroundAtrial fibrillation (AF) is common among patients in the intensive care unit (ICU) and can be triggered by severe illness or preexisting conditions. It is debated if AF is an independent predictor of poor outcome. MethodsData derives from a single center retrospective registry including all patients with a stay on the medical ICU for >24 h. The primary endpoint was ICU survival. Secondary endpoints included receiving mechanical support (renal, respiratory or circulatory), hemodynamic parameters during AF, rate and rhythm control strategies, anticoagulation, and documentation. ResultsA total of 616 patients (male gender 62.3%, median age 75 years) were included in our analysis. New-onset AF was diagnosed in 87 patients (14.1%), 136 (22.1%) presented with preexisting AF, and 393 (63.8%) did not develop AF. Initial episodes of new-onset AF exhibited higher hemodynamic instability than episodes in preexisting cases, with elevated heart rates and increased catecholamine doses (both p < 0.001). ICU survival in new-onset AF was 80.5% (70/87) compared to 92.4% (363/393) in patients without AF (OR 0.340, CI 0.182–0.658, p < 0.001). Likewise, ICU survival in preexisting AF was 86.8% (118/136) was significantly lower compared to no AF (OR 0.542, CI 0.290–0.986, p = 0.050*). Independent predictors of ICU survival for patients were atrial fibrillation (p = 0.016), resuscitation before or during ICU stay (p < 0.001), and receiving acute dialysis on ICU (p = 0.002). ConclusionsICU survival is noticeably lower in patients with new-onset or preexisting atrial fibrillation compared to those without. Patients who develop new-onset AF during their ICU stay warrant special attention for both short-term and long-term care strategies.