Astrid Paul Nordin

Background Atrial fibrillation (AF) is linked to significant morbidity and mortality, with ischaemic stroke being a leading cause of death. Identifying modifiable risk and protective factors may help reduce stroke incidence in patients with AF. Methods This umbrella review evaluated meta-analyses of observational studies and randomised controlled trials (RCTs) to assess the association of protective and risk factors with stroke and transient ischaemic attack (TIA) in patients with AF. Observational associations were graded with the Ioannidis framework. Associations from RCTs and non-randomised baseline factors in meta-analyses of RCTs were assessed with GRADE (Grading of Recommendations Assessment, Development and Evaluation). Composite risk scores were summarised separately as risk-stratification tools. Results 35 studies were included, comprising 23 meta-analyses of observational studies, reporting on 45 associations and 22 meta-analyses of RCTs on 24 associations based on data from over 7 276 000 participants. Among observational studies, only high levels of N-terminal pro-brain Natriuretic Peptide (NT-proBNP) provided convincing evidence of stroke risk. Previous stroke/TIA and age (65–74 years) were also associated with stroke, supported by a highly suggestive level of evidence. Among meta-analyses of non-randomised factors, female sex, kidney failure, non-paroxysmal AF and type 2 diabetes mellitus were risk factors with moderate to high evidence. However, other well-established risk factors, such as hypertension and vascular disease, were associated with stroke; however, they were supported with a weak level of evidence. Conclusions Despite stroke being the most severe complication of AF, this umbrella review reveals that few risk factors are supported by high-level evidence. Our findings confirm that elevated NT-proBNP, age and prior stroke are credible stroke risk factors in patients with AF. However, risk factors with weaker evidence, such as hypertension and vascular disease, require further investigation to clarify their actual impact. PROSPERO registration number CRD42023471263.

Aims: Voltage-based ablation is a promising catheter ablation strategy for atrial fibrillation (AF) in which low-voltage zones (LVZs) are targeted as a complement to pulmonary vein isolation (PVI). In a randomized setting, we intend to investigate whether PVI plus ablation of LVZs, compared to PVI-only, decreases the incidence of arrhythmia recurrence and improves health-related quality of life (HRQoL) in patients with persistent AF and LVZs. Methods and results: Individually designed ablation of low-voltage areas in persistent atrial fibrillation trial (IDEAL-AF; NCT04377594) is a multi-centre, randomized, controlled clinical trial. Patients with persistent AF and LVZs ≥ 3.0 cm² outside the PVI ablation lines will be randomized in a 1:1 ratio to either PVI or PVI plus LVZ ablation. The primary outcome will be the recurrence of atrial arrhythmias off anti-arrhythmic drugs during 12 months of follow-up after one to two ablation procedures within 6 months. A 3-month blanking period will be applied after the first procedure. Patients will be monitored using a smart phone-based ECG recording device throughout the follow-up period. With an anticipated enrolment of 936 patients, this study has 80% power to detect a 20% absolute risk reduction in the primary endpoint. Additionally, HRQoL improvement will be assessed using three questionnaires. Conclusion: IDEAL-AF is a multi-centre, randomized, controlled clinical trial investigating whether ablation of LVZs in addition to PVI reduces the recurrence rate of atrial arrhythmias and improves HRQoL compared to PVI-only in patients with persistent AF and LVZs. This study has the potential to modify recommendations regarding ablation techniques for this specific patient cohort.

Introduction: The presence of low‐voltage zones (LVZs) in the left atrium (LA) is associated with the recurrence of atrial fibrillation (AF) following pulmonary vein isolation (PVI). However, there is variability and conflict in the data regarding predictors of LVZs as reported in previous studies. The objective of this study was to identify predictors for the presence of LVZs in a cohort of patients with persistent AF.Methods: The study prospectively enrolled 439 patients with persistent AF who were scheduled for ablation. Voltage map of the LA was collected using a multipolar catheter. An LVZ was defined as an area of ≥3 cm² exhibiting a peak‐to‐peak bipolar voltage of p = .002); female sex (OR = 4.83, 95% CI = 2.66–8.76, p < .001); coronary artery disease (CAD) (OR = 3.20, 95% CI = 1.32–7.77, p = .01) and enlarged LA diameter (OR = 1.10, 95% CI = 1.04–1.17, p = .001). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the final model was 0.829.Conclusion: Approximately 25% of the patients with persistent AF had LVZs. Advanced age, female sex, CAD, and a larger LA were independent predictors for LVZs with the model demonstrating a very good AUC for the ROC curve. These findings hold the potential to be used to tailor the ablation procedure for the individual patient.

Aims: Controversy remains as to whether the exercise stress test (EST) is sufficient for risk evaluation in patients with pre-excitation. This study aims to clarify the usefulness of EST in risk stratification in both asymptomatic and symptomatic patients presenting with pre-excitation. Methods and results: This prospective study includes consecutive asymptomatic and symptomatic patients with pre-excitation referred for risk assessment. All participants performed an incremental EST (bicycle) prior to an electrophysiology study (EPS). Primary data from the EST included loss of pre-excitation during exercise, and primary data from the EPS included the measurement of accessory pathway effective refractory period (APERP), shortest pre-excited RR interval (SPERRI), and inducible arrhythmia with the use of a beta-adrenergic receptor agonist if deemed necessary. One hundred and sixty-four patients (59 asymptomatic, 105 symptomatic) completed an EST and EPS. Forty-five patients (27%) demonstrated low-risk findings on EST, of which 19 were asymptomatic and 26 were symptomatic. Six patients with low-risk EST findings had SPERRI/APERP ≤ 250 ms at EPS, and two of them were asymptomatic. The sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of low-risk EST for excluding patients with SPERRI/APERP ≤ 250 ms were 40, 91, 87, 51, and 60%, respectively. The number of patients with inducible arrhythmia at EPS was similar in the asymptomatic (36, 69%) and symptomatic (73, 61%) groups. Conclusion: Sudden loss of pre-excitation during EST has a low NPV in excluding high-risk APs. The EPS with the use of isoproterenol should be considered to accurately assess the risk of patients with pre-excitation regardless of symptoms (ClinicalTrials.gov Identifier: NCT03301935).

Evaluation of the diagnostic accuracy of a rhythm recording device, for detection of atrial tachyarrhythmia (ATA) and atrial fibrillation (AF) compared to 12-lead-electrocardiogram (12-L-ECG).Two h...

Aim: Data on ablation for atypical recurrent atrioventricular nodal reentry tachycardia (AVNRT) and long‐term follow‐up are generally sparse. Furthermore, the rate of recurrence and safety of cryoablation for atypical AVNRT has not been established. We compared patients cryoablated for atypical AVNRT and typical AVNRT during long‐term follow‐up.Methods: All patients (n = 2612) who underwent catheter ablation for AVNRT at the Karolinska University Hospital between January 2009 and August 2019 were analyzed. A total of 91 patients undergoing first‐time cryoablation for atypical AVNRT were included. A control group with first‐time cryoablation for typical AVNRT was matched in a 1:1 ratio. Patients were followed‐up for recurrences for a median of 5.0 years (interquartile range: 3.1–7.5 years).Results: After 5 years, AVNRT recurrence occurred in 10 patients (11.0%) in the atypical AVNRT group and in 8 patients (8.8%) in the typical AVNRT group (hazard ratio: 1.31 [95% confidence interval: 0.52–3.32]; p = 0.568). The duration of the index procedure was significantly longer for atypical compared to typical AVNRT ablation (132.1 ± 49.2 min vs. 110.1 ± 38.8 min; p = 0.001). Transient AV blocks occurred in a similar fashion in the atypical compared to typical group (11 [12.1%] vs. 4 [4.9%]; p = 0.103). However, no ablation induced persistent AV block developed in either group.Conclusion: Cryoablation for atypical AVNRT showed similar rate of recurrences and safety compared to typical AVNRT during long‐term follow‐up.

Aims: This study evaluates the incidence of procedural complications related to catheter ablation of atrial fibrillation (AF) to assess the potential feasibility and safety of same‐day discharge in a large cohort.Methods: We performed an analysis of prospectively collected data of complications of all patients staying overnight after undergoing AF ablation between 2001 and 2020 at a tertiary center. Using medical records, we analyzed complications occurring intraprocedurally until 6 h postablation and between 6 h postablation and discharge the day after the ablation procedure.Results: In 5414 AF ablations, we identified a total of 108 (2.0%) major complications occurring intraprocedural or before discharge. Most major complications occurred intraprocedurally or within 6 h after the procedure (n = 96, 1.8%). Twelve (0.2%) major complications occurred between 6 h Postablation and discharge. The most common of these major complications were congestive heart failure (n = 6) and transient ischemic attack (TIA, n = 4). During this time span, 61 (1.1%) minor complications occurred. Factors independently associated with major complications intraprocedurally and until discharge were body mass index (BMI) ≥ 30 kg/m² (p = .009), significant valvular disease (p = .001), cardiomyopathy (p < .001), prior stroke or TIA (p = .014), first‐time procedure versus repeat procedure (p = .013), cryoablation versus radiofrequency (p < .001), and procedure duration (p < .001).Conclusion: After AF ablation, very few complications occurred between 6 h postprocedure and discharge the next day. Therefore, same‐day discharge is a safe option for a majority of patients.

Aim: To investigate the association of sinus heart rate pre- and post-ablation and recurrence rates in patients undergoing catheter ablation for atrial fibrillation. Methods: Between January 2012 and December 2017, data of 482 patients undergoing their first pulmonary vein isolation (PVI) were included. All patients were followed-up for 12 months and were screened for any atrial tachyarrhythmia. Sinus heart rate measurements were recorded before (PRE), directly post ablation (POST) and 3 months post ablation (3M). Results: In the total study population, the mean resting sinus heart rate at PRE (mean 57.9 bpm (95% CI, 57.1–58.7 bpm)) increased by over 10 bpm to POST (mean 69.4 bpm (95% CI, 68.5–70.3 bpm); p<0.001) followed by a slight decrease at 3M (mean 67.3 bpm (95% CI, 66.4–68.2 bpm)) but still remaining higher compared to PRE (p<0.001). This pattern was observed in patients with and without recurrences at PRE, POST and 3M respectively (both p<0.001). However, only at 3M, there was a significant difference in mean heart rate being lower in patients with compared to patients without recurrences (p=0.031). In this regard, patients with a heart rate ≥60 bpm at 3M and a heart rate change ≥11 bpm (PRE to 3M) had a favorable outcome in terms of recurrences compared to the remaining patients (HR 0.61 (95% CI, 0.44–0.84), p=0.002 and HR 0.55 (95% CI, 0.40–0.76), p<0.001, respectively). These variables remained independently associated in multivariable analysis. Conclusion: Our study confirms the impact of PVI on cardiac autonomic function with a significant heart increase post-ablation. A heart rate ≥60bpm at 3M and a heart rate change ≥11 bpm (PRE to 3M) are associated with a favorable outcome in terms of recurrences. Funding Acknowledgement: Type of funding source: Foundation. Main funding source(s): German Research Foundation