Atrial fibrillation (AF) remains the most common cardiac arrhythmia worldwide and is associated with significant morbidity and mortality. The European Society of Cardiology (ESC)/European Association for Cardio-Thoracic Surgery (EACTS) have recently released the 2024 guidelines for the management of AF. This review highlights 10 novel aspects of the ESC/EACTS 2024 Guidelines. The AF-CARE framework is introduced, a structural approach that aims to improve patient care and outcomes, comprising of four pillars: [C] Comorbidity and risk factor management, [A] Avoid stroke and thromboembolism, [R] Reduce symptoms by rate and rhythm control, and [E] Evaluation and dynamic reassessment. Additionally, graphical patient pathways are provided to enhance clinical application. A significant shift is the new emphasis on comorbidity and risk factor control to reduce AF recurrence and progression. Individualized assessment of risk is suggested to guide the initiation of oral anticoagulation to prevent thromboembolism. New guidance is provided for anticoagulation in patients with trigger-induced and device-detected sub-clinical AF, ischaemic stroke despite anticoagulation, and the indications for percutaneous/surgical left atrial appendage exclusion. AF ablation is a first-line rhythm control option for suitable patients with paroxysmal AF, and in specific patients, rhythm control can improve prognosis. The AF duration threshold for early cardioversion was reduced from 48 to 24 h, and a wait-and-see approach for spontaneous conversion is advised to promote patient safety. Lastly, strong emphasis is given to optimize the implementation of AF guidelines in daily practice using a patient-centred, multidisciplinary and shared-care approach, with the simultaneous launch of a patient version of the guideline.

Although catheter ablation (CA) is successful for the treatment of paroxysmal atrial fibrillation (AF), results are less satisfactory in persistent AF. Hybrid ablation (HA) results in better outcomes in patients with persistent atrial fibrillation (persAF), as it combines a thoracoscopic epicardial and transvenous endocardial approach in a single procedure. The purpose of this study was to compare the effectiveness and safety of HA with CA in a prospective, superiority, unblinded, randomized controlled trial. Forty-one ablation-naive patients with (long-standing)-persAF were randomized to HA (n = 19) or CA (n = 22) and received pulmonary vein isolation, posterior left atrial wall isolation and, if needed, a cavotricuspid isthmus ablation. The primary efficacy endpoint was freedom from any atrial tachyarrhythmia >5 minutes off antiarrhythmic drugs after 12 months. The primary and secondary safety endpoints included major and minor complications and the total number of serious adverse events. After 12 months, the freedom of atrial tachyarrhythmias off antiarrhythmic drugs was higher in the HA group compared with the CA group (89% vs 41%, P = 0.002). There was 1 pericarditis requiring pericardiocentesis and 1 femoral arteriovenous-fistula in the HA group. In the CA arm, 1 bleeding from the femoral artery occurred. There were no deaths, strokes, need for pacemaker implantation, or conversions to sternotomy, and the number of (serious) adverse events was comparable between groups (21% vs 14%, P = 0.685). Hybrid AF ablation is an efficacious and safe procedure and results in better outcomes than catheter ablation for the treatment of patients with persistent AF. (Hybrid Versus Catheter Ablation in Persistent AF [HARTCAP-AF]; NCT02441738).

The role of gender in decision-making for oral anticoagulation in patients with atrial fibrillation (AF) remains controversial. The population cohort study used electronic healthcare records of 16 587 749 patients from UK primary care (2005–2020). Primary (composite of all-cause mortality, ischaemic stroke, or arterial thromboembolism) and secondary outcomes were analysed using Cox hazard ratios (HR), adjusted for age, socioeconomic status, and comorbidities. 78 852 patients were included with AF, aged 40–75 years, no prior stroke, and no prescription of oral anticoagulants. 28 590 (36.3%) were women, and 50 262 (63.7%) men. Median age was 65.7 years (interquartile range 58.5–70.9), with women being older and having other differences in comorbidities. During a total follow-up of 431 086 patient-years, women had a lower adjusted primary outcome rate with HR 0.89 vs. men (95% confidence interval [CI] 0.87–0.92; P < .001) and HR 0.87 after censoring for oral anticoagulation (95% CI 0.83–0.91; P < .001). This was driven by lower mortality in women (HR 0.86, 95% CI 0.83–0.89; P < .001). No difference was identified between women and men for the secondary outcomes of ischaemic stroke or arterial thromboembolism (adjusted HR 1.00, 95% CI 0.94–1.07; P = .87), any stroke or any thromboembolism (adjusted HR 1.02, 95% CI 0.96–1.07; P = .58), and incident vascular dementia (adjusted HR 1.13, 95% CI 0.97–1.32; P = .11). Clinical risk scores were only modest predictors of outcomes, with CHA₂DS₂-VA (ignoring gender) superior to CHA₂DS₂-VASc for primary outcomes in this population (receiver operating characteristic curve area 0.651 vs. 0.639; P < .001) and no interaction with gender (P = .45). Removal of gender from clinical risk scoring could simplify the approach to which patients with AF should be offered oral anticoagulation. The impact of gender on adverse events in patients with atrial fibrillation (AF) based on a population cohort study using electronic healthcare records from UK primary care (2005–20).

Background: Atrial cardiomyopathy (atCM) is an emerging prognostic factor in cardiovascular disease. Fibrotic remodeling, cardiomyocyte hypertrophy, and capillary density are hallmarks of atCM. The contribution of etiological factors and atrial fibrillation (AF) to the development of differential atCM phenotypes has not been quantified. This study aimed to evaluate the association between histological features of atCM and the clinical phenotype. Methods and Results: We examined left atrial (LA, n=95) and right atrial (RA, n=76) appendages from a European cohort of patients undergoing cardiac surgery. Quantification of histological atCM features was performed following wheat germ agglutinin/CD31/vimentin staining. The contributions of AF, heart failure, sex, and age to histological characteristics were determined with multiple linear regression models. Persistent AF was associated with increased endomysial fibrosis (LA: +1.13±0.47 μm, P =0.038; RA: +0.94±0.38 μm, P =0.041), whereas total extracellular matrix content was not. Men had larger cardiomyocytes (LA: +1.92±0.72 μm, P <0.001), while women had more endomysial fibrosis (LA: +0.99±0.56 μm, P =0.003). Patients with heart failure showed more endomysial fibrosis (LA: +1.85±0.48 μm, P <0.001) and extracellular matrix content (LA: +3.07±1.29%, P =0.016), and a higher capillary density (LA: +0.13±0.06, P =0.007) and size (LA: +0.46±0.22 μm, P =0.044). Fuzzy k‐means clustering of histological features identified 2 subtypes of atCM: 1 characterized by enhanced endomysial fibrosis (LA: +3.17 μm, P <0.001; RA: +2.86 μm, P <0.001), extracellular matrix content (LA: +3.53%, P <0.001; RA: +6.40%, P <0.001) and fibroblast density (LA: +4.38%, P <0.001), and 1 characterized by cardiomyocyte hypertrophy (LA: +1.16 μm, P =0.008; RA: +2.58 μm, P <0.001). Patients with fibrotic atCM were more frequently female (LA: odds ratio [OR], 1.33, P =0.002; RA: OR, 1.54, P =0.004), with persistent AF (LA: OR, 1.22, P =0.036) or heart failure (LA: OR, 1.62, P <0.001). Hypertrophic features were more common in men (LA: OR=1.33, P =0.002; RA: OR, 1.54, P =0.004). Conclusions: Fibrotic atCM is associated with female sex, persistent AF, and heart failure, while hypertrophic features are more common in men.

Aims: Postoperative atrial fibrillation (POAF) after cardiac surgery is an independent predictor of stroke and mortality late after discharge. We aimed to determine the burden and predictors of early (up to 5th postoperative day) and late (after 5th postoperative day) new-onset atrial fibrillation (AF) using implantable loop recorders (ILRs) in patients undergoing open chest cardiac surgery. Methods and results: Seventy-nine patients without a history of AF undergoing cardiac surgery underwent peri-operative high-resolution mapping of electrically induced AF and were followed 36 months after surgery using an ILR (Reveal XT™). Clinical and electrophysiological predictors of late POAF were assessed. POAF occurred in 46 patients (58%), with early POAF detected in 27 (34%) and late POAF in 37 patients (47%). Late POAF episodes were short-lasting (mostly between 2 min and 6 h) and showed a circadian rhythm pattern with a peak of episode initiation during daytime. In POAF patients, electrically induced AF showed more complex propagation patterns than in patients without POAF. Early POAF, right atrial (RA) volume, prolonged PR time, and advanced age were independent predictors of late POAF. Conclusions: Late POAF occurred in 47% of patients without a history of AF. Patients who develop early POAF, with higher age, larger RA, or prolonged PR time have a higher risk of developing late POAF and may benefit from intensified rhythm follow-up after cardiac surgery. Clinicaltrials.gov number: NCT01530750.