Morten Lock Hansen

Aims: Catheter ablation (CA) for atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM) poses unique challenges due to structural and electrical remodelling. This study examines AF recurrence and complication rates following CA in HCM patients compared to a matched AF non-HCM cohort. Methods and results: A retrospective cohort study of Danish nationwide registries from 2010 to 2022 was conducted. Rates of AF recurrence, heart failure, ischaemic stroke, and death were analysed using propensity score matching and Cox regression models. Among 28 231 patients undergoing first-time CA for AF, 299 had a confirmed diagnosis of HCM. Patients with HCM demonstrated significantly higher rates of AF recurrence compared to a matched non-HCM cohort, with 40% experiencing recurrence vs. 30% in the non-HCM group after 1 year and 67% vs. 58% after 5 years [hazard ratio (HR) 1.41, P < 0.001]. Despite the elevated recurrence rates, no significant differences were observed in the incidence of ischaemic stroke (HR 0.99, P & 0.9) or all-cause mortality (HR 1.18, P & 0.3). However, the risk of heart failure was significantly increased (HR 2.45, P & <0.001). Conclusion: HCM patients experience higher AF recurrence rates post-CA as well as a higher risk of heart failure. These findings highlight the need for tailored strategies to improve outcomes in this high-risk group.

Aims: Catheter ablation (CA) is widely used for atrial fibrillation (AF), but pulmonary vein isolation (PVI) alone is less effective in persistent AF (peAF) than paroxysmal AF (PAF). Real-world data on patient selection, outcomes, and complications with PVI or PVI plus (≥1 additional line or CFAE/ganglionated plexi ablation) are limited. We examined characteristics, trends, recurrence, and complications in peAF ablations. Methods and results: Patients with peAF undergoing first-time catheter ablation between 2010 and 2020 were identified from the Danish National Ablation Database. They were categorized by ablation strategy (PVI or PVI plus), and baseline characteristics and trends were assessed. AF recurrence was analysed using cumulative incidence at one and five years, and across procedural years. Major adverse cardiovascular events (MACE) and procedure-related complications were also examined. Among 4144 peAF patients, 3.417 received PVI and 727 PVI plus. Baseline characteristics were similar, except the PVI plus group had longer diagnosis-to-ablation-time (mean 5.67 years vs. 3.9 years, P < 0.001) and more severe atrial enlargement (14.8% vs. 9.8%, P < 0.001). AF recurrence was higher with PVI plus at one- and five-years (54% vs. 46%, 77% vs. 68%). Recurrence rates declined over time (2010–2013 vs. 2018–2020). PVI plus use decreased from 58% to 15%. MACE and complication rates were low and similar. Conclusion: PVI plus was used less frequently over time and was associated with longer diagnosis-to-ablation times and larger left atria. We observed a proportional decline for both groups in AF recurrence across procedural years, and complication rates were low and similar.

Introduction: Pulmonary vein isolation (PVI) is the cornerstone in atrial fibrillation (AF) ablation but achieving durable PVI remains a challenge. The radiofrequency balloon (RFB) is a “single‐shot” ablation catheter for PVI that offers selective energy titration from 10 surface electrodes and 3D mapping system integration. The durability of RFB PVI has not been investigated.Methods: The objective of this study was to evaluate the durability of RFB PVI by protocol‐mandated remaps in patients with paroxysmal or persistent AF referred for AF ablation at a high‐volume center. RFB procedures were performed under conscious sedation, PVI assessed by high‐density mapping, bidirectional block confirmed after a waiting period of ≥ 20 min, and dormant conduction assessed by adenosine injections. After 4–6 months patients underwent a remap study for assessment of PVI durability by high‐density mapping and assessment of bidirectional block.Results: Forty‐five patients were enrolled, 43 completed the RFB PVI, and 35/43 (81%) completed the remap study: 26% female, 43% persistent AF, median age 65 (interquartile range: 61–69) years, median CHA₂DS₂‐VASc score 1 (0–2), and median left atrial volume 31 (25–42) mL/m². Acute PVI was achieved in 99% of pulmonary veins (PVs) but focal radiofrequency touch‐up lesions were required in 31% of patients. After 5.4 (4.9–6.1) months, 71% of PVs were durably isolated, and 29% of patients had all PVs durably isolated; 86% of patients were free from documented atrial tachyarrhythmias.Conclusion: The durability of RFB PVI achieved under conscious sedation was relatively low. However, medium‐term freedom from clinical recurrent arrhythmia was favorable.Trial Registration: URL: https://www.clinicaltrials.gov. Unique Identifier: NCT06296888.

Hypertrophic cardiomyopathy (HCM) is a complex genetic disorder that has garnered significant attention because of its diverse manifestations, including arrhythmias and heightened risk of sudden cardiac death. Advances in precision diagnostics, such as genetic testing and cardiac imaging with late gadolinium enhancement, have refined HCM diagnosis, enabling targeted therapeutic and risk stratification approaches. AF, prevalent in HCM, exacerbates symptoms and stroke risk, while ventricular arrhythmias pose a direct threat to survival. Catheter ablation offers symptom relief in AF patients with HCM, yet recurrence remains high because of unique myocardial changes, highlighting the need for refined patient selection and long-term monitoring. The risk of sudden cardiac death in HCM, particularly in younger individuals, underscores the importance of precise risk stratification tools such as the European Society of Cardiology HCM Risk-SCD model. The expanding role of ICDs and emerging pharmacological agents, including myosin inhibitors, marks a shift toward more individualised management of HCM. This review integrates recent developments in arrhythmia management, targeted therapies and risk assessment, offering a comprehensive perspective on HCM tailored to improve clinical outcomes through a precision-medicine lens.

Introduction: Atrial tachyarrhythmia recurrence during the blanking period (early ATA) after pulmonary vein isolation (PVI) is associated with an increased risk of later recurrence, but its relationship with pulmonary vein reconduction (PVR) is poorly understood. The objective of the present study was to evaluate the relationship between early ATA and PVR. Second, to provide data on the optimal blanking period by (a) evaluating how the predictive values of ATA for PVR are affected by blanking period duration, and (b) assessing the temporal development in atrial fibrillation (AF) burden.Methods: In this RACE‐AF substudy, 91 patients with paroxysmal AF undergoing PVI randomized to radiofrequency or cryoballoon ablation were included. All patients received an implantable cardiac monitor and underwent a protocol‐mandated repeat procedure after 4–6 months for assessment of PVR. ATA ≥ 30 s. ≤ 90 days after PVI constituted early ATA.Results: PVR was found in 37/54 (69%) patients with early ATA and in 11/37 (30%) patients without (p < .001). The positive predictive value of ATA for PVR was independent of blanking period duration (range 0–90 days). In both patients with and without PVR, AF burden was higher in the first month after PVI, but AF burden from the second month was similar to AF burden after the conventional blanking period.Conclusion: Early ATA indicates PVR, and the positive predictive value is independent of the blanking period duration. Altogether, the results of this study support substantially shortening the blanking period after PVI for paroxysmal AF.

Introduction: Reconnections to pulmonary vein (PV) triggers of atrial fibrillation (AF) are the primary cause of AF recurrence after PV isolation (PVI) with radiofrequency (RF) or cryoballoon catheter ablation (CRYO), but method‐specific contributions to PV reconduction pattern and conductive gap location are incompletely understood.Methods: The objective of this radiofrequency versus cryoballoon catheter ablation for paroxysmal atrial fibrillation substudy was to determine procedure‐specific patterns of PV reconduction in a randomized population with protocol‐mandated repeat procedures, irrespective of AF recurrence. Each PV was assessed in turn and PV reconnection sites were identified by high‐density electroanatomical mapping and locating the earliest activation site. Gap locations were verified by PV re‐isolation.Results: In 98 patients, 81% versus 76% previously isolated PVs remained isolated after CRYO versus RF (risk ratio [RR]: 1.06; 95% confidence interval [CI]: 0.96–1.18; p = .28). There were no significant differences for any PV: left superior PV: 90% versus 80%; left inferior PV: 80% versus 78%; right superior PV: 81% versus 80%, and right inferior PV: 76% versus 73%. For each reconnected PV, 34% of ipsilateral PVs were also reconnected after CRYO compared with 64% after RF (RR: 0.54; 95% CI: 0.32–0.90; p = .01). After RF, gaps were clustered by the carina and adjacent segments, whereas they were more heterogeneously distributed after CRYO.Conclusion: Although RF and CRYO produce similar proportions of durably isolated PVs, gap locations appear to develop in procedure‐specific patterns. After RF, ipsilateral PV reconduction is more frequent and gap sites cluster by the carina, suggesting that this region should be selectively ablated for more durable PVI.

Aims: Overweight is associated with increased risk of atrial fibrillation (AF), but the impact of overweight and AF recurrence after ablation is less clear. Despite this, an increasing number of AF ablations are carried out in overweight patients. We investigated the impact of body mass index (BMI) on AF recurrence rates after ablation.Methods and results: Through Danish nationwide registers, all patients undergoing first-time AF ablation between 2010 and 2018 were identified. Exposure of interest was BMI. The primary outcome was recurrent AF, defined from either any usage of antiarrhythmic medication, AF hospitalization, cardioversion, or re-ablation. A total of 9188 patients were included. Median age and interquartile range was 64 (60–75) in the normal-weight group and 60 (53–66) in the morbidly obese. There was an increase in comorbidity burden with increasing BMI, including a higher prevalence of heart failure, chronic obstructive pulmonary disease, diabetes, and hypertension. At 1- and 5-year follow ups, recurrence rates of AF increased incrementally by BMI categories. The hazard ratios and 95% confidence intervals of recurrent AF after ablation were 1.15 (1.07–1.23), 1.18 (1.09–1.28), and 1.26 (1.13–1.41) in overweight, obese, and morbidly obese, respectively, compared with normal-weight patients. Procedure duration and X-ray dose exposure also increased with increasing BMI.Conclusion: Following AF ablation, recurrence rates of AF increased incrementally with increasing BMI. Therefore, aggressive weight management pre ablation in overweight patients could potentially provide substantial benefits and improve short- and long-term outcomes after ablation.

Background: Knowledge is scarce regarding how multimorbidity is associated with therapeutic decisions regarding oral anticoagulants (OACs) in patients with atrial fibrillation. Methods and Results: We conducted a cross‐sectional study of hospitalized patients with atrial fibrillation using the Get With The Guidelines‐Atrial Fibrillation registry from 2013 to 2019. We identified patients ≥65 years and eligible for OAC therapy. Using 16 available comorbidity categories, patients were stratified by morbidity burden. A multivariable logistic regression model was used to determine the odds of receiving OAC prescription at discharge by morbidity burden. We included 34 174 patients with a median (interquartile range) age of 76 (71–83) years, 56.6% women, and 41.9% were not anticoagulated at admission. Of these patients, 38.6% had 0 to 2 comorbidities, 50.7% had 3 to 5 comorbidities, and 10.7% had ≥6 comorbidities. The overall discharge OAC prescription was high (85.6%). The prevalence of patients with multimorbidity increased from 59.7% in 2014 to 64.3% in 2019 ( P trend=0.002). Using 0 to 2 comorbidities as the reference, the adjusted odds ratio (95% CI) of OAC prescription were 0.93 (0.82, 1.05) for patients with 3 to 5 comorbidities and 0.72 (0.60, 0.86) for patients with ≥6 comorbidities. In those with ≥6 comorbidities, the most common reason for nonprescription of OACs were frequent falls/frailty (31.0%). Conclusions: In a contemporary quality‐of‐care database of hospitalized patients with atrial fibrillation eligible for OAC therapy, multimorbidity was common. A higher morbidity burden was associated with a lower odds of OAC prescription. This highlights the need for interventions to improve adherence to guideline‐recommended anticoagulation in multimorbid patients with atrial fibrillation.

To examine the risk of gastrointestinal adverse effects associated with dabigatran use compared with warfarin among patients with atrial fibrillation (AF). Patients with AF and no history of gastrointestinal diseases initiating dabigatran or warfarin were identified from Danish nationwide registries from 22 August 2011 until 31 December 2012. Patients were classified as naive or experienced users, according to prior use of oral anticoagulant (OAC) therapy. The risk of subsequent proton pump inhibitor (PPI) use, upper dyspepsia-like diagnoses (gastroesophageal reflux, gastritis, gastric, and duodenal ulcer) and gastrointestinal bleeding requiring hospitalization, gastroscopy, and discontinuation of dabigatran and warfarin was examined by cumulative incidence rates and multivariable adjusted Cox regression models. We identified five groups: OAC-naive warfarin (n = 4534); OAC-naive dabigatran 110 mg b.i.d. (dabigatran 110) (n = 1168); OAC-naive dabigatran 150 mg b.i.d. (dabigatran 150) (n = 1844); OAC-experienced dabigatran 110 (n = 1143); and OAC-experienced dabigatran 150 (n = 1748). Compared with OAC-naive warfarin, the rate of initiating PPIs was significantly increased for OAC-naive dabigatran 110 [hazard ratio (HR), 1.24; 95% confidence interval (CI), 1.02–1.50]. Other dabigatran regimes were not associated with a higher risk of initiating PPIs, upper dyspepsia-like diagnoses, gastrointestinal bleeding, or gastroscopy. The risk of discontinuation was increased for OAC-experienced dabigatran 150 (HR, 1.13; 95% CI, 1.02–1.25), but not for the other dabigatran-treated groups, relative to OAC-naive warfarin. Dabigatran was not associated with upper dyspepsia-like diagnoses or gastrointestinal bleeding requiring hospitalization, and gastroscopy. The risk of subsequent PPI use was increased for OAC-naive dabigatran 110 mg users, and the risk of discontinuation was increased for OAC-experienced dabigatran 150 mg users.