Mats Jensen-Urstad

Aims: Ventricular tachyarrhythmias (VT/VF) are common among patients with prior myocardial infarction (MI). MANTRA-VT trial was designed to compare the efficacy and safety of early substrate-based radiofrequency catheter ablation (RFCA) to antiarrhythmic drug (AAD) therapy for ventricular tachyarrhythmias. Methods and results: We randomly assigned 58 AAD naïve post MI patients with implantable cardioverter defibrillator (ICD) and at least one documented VT/VF episode after the device implantation to an initial treatment strategy of substrate-based RFCA or AAD therapy. The primary endpoint was cumulative number of ventricular tachyarrhythmias (VT/VF burden) at 12 months. The secondary endpoints included all-cause mortality, hospitalization, adverse events, and VT/VF burden at 24 months. Analyses were performed on an intention-to-treat basis. The median number of VT/VF episodes at 12 months was zero in both the RFCA (range 0–3) and the AAD group (range 0–23) (P = 0.454), whereas the rate of appropriate ICD shocks was 7% and 30% in the RFCA and the AAD groups (P = 0.026), respectively. During the extended follow-up, 82% of the patients in the RFCA group and 63% in the AAD group had no ICD therapies (P = 0.012). There was no significant difference between the groups in total mortality (HR 1.02, 95% CI 0.20–5.11, P = 0.86) and hospitalization (HR 1.35, 95% CI 0.36–5.09. P = 0.66) at 24 months. Therapy-related adverse events occurred in 3.6% and 16.7% of the patients in the RFCA and the AAD groups (P = 0.10), respectively. Conclusion: Early substrate-based RFCA was associated with reduced risk of ICD therapies, but with no meaningful difference in VT/VF burden, mortality, hospitalization, and adverse events.

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).

Purpose: Patients with WPW syndrome have an increased mortality rate compared to the general population. Although asymptomatic preexcitation has previously been considered benign, recent studies have found that also asymptomatic patients have clinical and electrophysiological factors associated with increased risk of sudden cardiac death. This study compares the baseline electrophysiological characteristics of accessory pathways in symptomatic and asymptomatic patients with preexcitation. We hypothesized that a significant proportion of asymptomatic patients has inducible orthodromic tachycardia during programmed electrical stimulation. Methods: This retrospective study includes 1853 patients with preexcitation who underwent invasive electrophysiological testing in two Swedish University Hospitals between 1991 and 2018. The mean age was 36 ± 17 years with a range of 3–89 years. Thirty-nine percent was women. A total of 269 patients (15%) were children younger than 18 years. Electrophysiological data included effective refractory period of the accessory pathway (APERP, in 1069 patients), tachycardia cycle length, inducibility and type of tachycardia, and AP localization. Results: A total of 1703 (93%) patients reported symptoms suggesting tachyarrhythmias before the study and 128 (7%) were asymptomatic. The proportion of potentially dangerous pathways with short APERP (≤ 250 ms) were similar in symptomatic and asymptomatic patients (187/949, 20% vs. 25/108, 23%) (P = 0.40) as was the mean APERP (303 ± 68 ms vs. 307 ± 75) (P = 0.61). The proportion of patients who had inducible arrhythmia was larger in the symptomatic group (64% vs. 31%) (P < 0.001). Conclusion: The results of this study strengthen the present guideline recommendation (IIA) to consider invasive risk assessment in patients with asymptomatic preexcitation.

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.

Palpitations, particularly common in women, are generally considered benign symptoms rarely caused by clinically important arrhythmias. Nevertheless, palpitations may cause anxiety, depression, and decreased health-related quality of life (HRQOL). This study investigates to what degree palpitations cause symptoms such as anxiety and depression and affect HRQOL in women and whether direct feedback of underlying heart rhythm during palpitations decrease anxiety and depression and increase HRQOL in women. The study included 821 women, age 21–88 years (mean 57 ± 11 years), with symptomatic palpitations recruited using social media. For 60 days, the participants used a handheld electrocardiogram (ECG)-recording device (Coala Heart Monitor) connected to their smartphones. ECG was recorded twice a day and when symptoms were present and was automatically algorithm-interpreted with immediate response to the user. Non-benign arrhythmias were also analysed manually. Questionnaires addressing anxiety and depression—Hospital Anxiety and Depression Scale (HADS), Generalized Anxiety Disorder (GAD-7), HRQOL (RAND-36), and Symptoms Checklist: Frequency and Severity (SCL)—were analysed before and after the data were collected. A total of 101 804 ECG recordings were automatically analysed. In 94%, sinus rhythm or premature atrial/ventricular contraction were recorded; in 6%, atrial fibrillation or supraventricular tachycardia were recorded. Apart from premature ventricular contractions, no ventricular arrhythmias were documented. Anxiety and depression (HADS and GAD-7) decreased (P < 0.001) as did frequency and severity of symptoms, and HRQOL increased in all domains (P < 0.001) at the 2-month follow-up. Instant analysis of the ECG with direct response during palpitations decreases symptoms, anxiety, and depression and increases HRQOL in women.

Background: In general, most clinical studies have long recruitment periods. Signing the informed consent is particularly time-consuming when the participant must meet physically with the researchers. Therefore, introducing fully web-based techniques with the use of eAuthentication (BankID) and new digital electrocardiogram (ECG) monitoring could speed up inclusion time, increase adherence, and also reach out to more remote regions. Objective: The objectives of this study were to explore whether inclusion of a large number of participants could be realized quickly by using a total digital approach both for information and signing of informed consent, along with ECG monitoring and instant feedback on a mobile device. We also explored whether this approach can increase adherence in registration of ECG recordings and answering questionnaires, and if it would result in a more geographically uniform distribution of participants covering a wide age span. Methods: Women with palpitations were intensively studied over 2 months by means of a handheld ECG monitoring device (Coala Heart Monitor). The device connects to a smartphone or tablet, which allows the participants to obtain the results immediately. Recruitment, study information, and signing the informed consent form with the help of BankID were performed in a completely digital manner. Results: Between March and May 2018, 2424 women indicated their interest in participating in the study. On June 19, 2018, presumptive participants were invited to log in and register. After 25 days, 1082 women were included in the study; among these, 1020 women fulfilled the inclusion criteria, 913 of whom completed all phases of the study: recording ECG using the handheld device, completion of the prestudy questionnaires, and completion of the poststudy questionnaires 2 months after the ECG recordings. The dropout rate was 9%. In total, 101,804 ECG recordings were made. The mean age was 56 (SD 11) years (range 21-88 years) and 35 participants were 75 years or older. The participants were evenly distributed between living in the countryside and in cities. Conclusions: Total digital inclusion recruitment of 1082 participants was achieved in only 25 days, and resulted in a good geographical distribution, excellent adherence, and ability to reach a vast age span, including elderly women. Studies using a total digital design would be particularly appealing during a pandemic since physical contact should be avoided as much as possible. Trial Registration: ISRCTN Registry ISRCTN22495299; http://www.isrctn.com/ISRCTN22495299

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