Treatment Of Atrial Fibrillation Research Articles

Comparison of Therapeutic Effects Between Pulsed Field Ablation and Cryoballoon Ablation in the Treatment of Atrial Fibrillation: A Systematic Review and Meta-analysis

Pulsed field ablation (PFA) is a novel nonthermal ablation technique for the treatment of atrial fibrillation (AF) patients, with safety comparable to traditional catheter ablation surgery. The present study aims to evaluate and compare the procedural efficiency and safety profiles of PFA and cryoballoon ablation (CBA) in the management of AF. We performed a systematic search across PubMed, the Cochrane Library, and Embase databases, encompassing the literature up to February 2024, to inform our systematic review and meta-analysis. When assessing outcome indicators, the risk ratio and its corresponding 95% confidence interval (CI) were calculated for dichotomous variables. For continuous variables, the mean difference (MD) and the associated 95% CI were determined. In this scenario, a relative risk (RR) value of less than 1 and an MD value of less than 0 are deemed favorable for the PFA group. This could translate to a reduced likelihood of procedural complications or enhanced procedural performance within the PFA group. In this analysis, 9 observational studies encompassing 2875 patients with AF were included. Among these, 38% (n = 1105) were treated with PFA, while 62% (n = 1770) received CBA. The results indicated that PFA was associated with a significantly shorter procedural duration compared with CBA, with an MD of −10.49 minutes (95% CI, −15.50 to −5.49; P < 0.0001). Nevertheless, no statistically significant differences were observed when comparing the 2 treatment cohorts concerning fluoroscopy time (MD, 0.71; 95% CI, −0.45 to 1.86; P = 0.23) and the recurrence of atrial arrhythmias during follow-up (RR, 0.95; 95% CI, 0.78–1.14; P = 0.57). In terms of perioperative complications, the PFA group showed a significantly decreased risk of phrenic nerve palsy (RR, 0.15; 95% CI, 0.06–0.39; P < 0.0001) and an increased risk of cardiac tamponade (RR, 3.48; 95% CI, 1.26–9.66; P = 0.02) compared with the CBA group. No significant differences were noted between the PFA and CBA groups regarding the incidence of stroke/transient ischemic attack (RR, 0.99; 95% CI, 0.30–3.22; P = 0.99), vascular access complication (RR, 0.87; 95% CI, 0.36–2.10; P = 0.76), atrial esophageal fistula (RR, 0.33; 95% CI, 0.01–8.13; P = 0.50), and major or minor bleeding events (RR, 0.39; 95% CI, 0.09–1.74; P = 0.22). Our research results indicate that compared with CBA, PFA not only shortens the procedure time but also demonstrates noninferiority in terms of fluoroscopy duration and the recurrence rate of atrial arrhythmias. PFA and CBA have both demonstrated their respective advantages in perioperative complications.

Abstract 4136804: Effect of Obesity on Arrhythmia Recurrence and Complications following Pulmonary Vein Isolation for Paroxysmal Atrial Fibrillation in the REAL-AF Registry

Introduction: Obesity is an important risk factor for atrial fibrillation and its prevalence in the United States is rising. The effect of obesity on outcomes following pulmonary vein isolation in a contemporary setting has not been extensively evaluated. Research Questions: - Is higher body mass index (BMI) associated with increased risk of atrial arrhythmia recurrence following pulmonary vein isolation? - Is higher BMI associated with increased risk of post-procedural complications? Method: - The REAL-AF (Real-world Experience of Catheter Ablation for the Treatment of Symptomatic Paroxysmal and Persistent Atrial Fibrillation; ClinicalTrials.gov Identifier: NCT04088071) Registry is a multicenter, prospective observational registry of patients undergoing radiofrequency catheter ablation of atrial fibrillation. We included 2666 patients with paroxysmal atrial fibrillation undergoing index ablation from January 2018 through April 2023. We excluded patients with missing covariates. - The primary outcome was freedom from atrial arrhythmia following ablation. Rhythm monitoring was standardized using patch monitor at 6 month and 1 year. Time-to-event analysis was performed using a 3-month blanking period. Results: - Baseline characteristics are shown in Table 1. The median follow-up was 382 days (IQR: 363-410). - There was a trend toward higher rate of atrial arrhythmia following ablation for patients in the highest BMI group compared with the reference group (BMI<25) ( BMI≥40: HR = 1.41 (0.94-2.12), p= 0.092). There was no difference in the rate of atrial arrhythmia for other BMI groups ( BMI 25 - <30: HR = 0.90 (0.65-1.23), p = 0.5; BMI 30 - <35: HR = 0.89 (0.64-1.23), p = 0.5; BMI 35 - <40: HR = 0.87 (0.57-1.32), p = 0.5). This trend persisted following adjustment for baseline covariates ( BMI 25 - <30: HR = 1.01 (0.77-1.33), p > 0.9; BMI 30 - <35: HR = 0.97 (0.72-1.32), p = 0.9; BMI 35 - <40: HR = 1.01 (0.66-1.55), p > 0.9; BMI≥40: HR = 1.57 (0.96-2.57), p =0.071). - First-pass isolation rates progressively decreased with higher BMI (Table 2). - Complication rates were low across all BMI groups (Table 2). Conclusions: - Severely obese patients with BMI ≥40 experience higher risk of atrial arrhythmia following radiofrequency catheter ablation of paroxysmal atrial fibrillation compared with normal weight individuals. This corresponds with lower rates of first-pass isolation at higher BMI. - Patients across BMI categories experience similarly low rates of procedural complication.

Abstract 4137927: Physicians’ Misrecognition of Stroke Risk in Patients with Atrial Fibrillation

Background: Current clinical practice guidelines for atrial fibrillation (AF) recommend stroke risk stratification and the use of oral anticoagulants (OACs) for patients at risk. However, physicians’ recognition of patients’ stroke risk may differ from the calculated risk, and the effect of this discrepancy on subsequent care remains unknown. Aims: We aimed to document treating physicians’ estimations of individual patients' stroke risk and assess its association with OAC utilization. Methods: A multicenter, prospective cohort study was conducted in two outpatient practices in Tokyo, Japan, between 2018 to 2020. Participants included patients with newly diagnosed AF or those referred for initial treatment for AF. Treating physicians were asked to document the patient's estimated risk of stroke in numbers. The estimations were categorized as low risk (<1.0%/year), intermediate risk (1.0%≤ to <2.0%/ year), and high risk (2.0%≤/year). We then calculated patients’ baseline CHA 2 DS 2 -VASc scores and divided them into three risk groups: 0 or 1 point as low risk, 2 points as intermediate risk, and 3 or more points as high risk. Higher risk categorization by physicians was defined as "overestimation," while lower risk categorization was defined as "underestimation." The independent association of physician-patient risk concordance with OAC use was explored by multivariable Logistic regression models. Results: Among the 285 patients enrolled in this study (mean age 68±12 years, male 72.6%), the mean CHA 2 DS 2 -VASc score was 2.3±1.6. Physicians correctly estimated stroke risk in 147 patients (51.6%), underestimated it in 25 patients (8.8%) and overestimated it in 113 patients (39.6%). OACs were used in 89.8% of patients whose stroke risk was correctly estimated, 72.0% of those whose stroke risk was underestimated, and 84.1% of patients whose health status was overestimated. After multivariable adjustment, the underestimation of stroke risk was independently associated with less use of OACs (adjusted odds ratio 0.23, 95% CI 0.061-0.85, P=0.028). Conclusions: In this cohort study, physician underestimation of stroke risk was not rare and associated with less use of OACs.

Abstract 4125076: Catheter Ablation Alone Versus Catheter Ablation With Combined Percutaneous Left Atrial Appendage Closure For Atrial Fibrillation: A Systematic Review and Meta-analysis

Background: Combined catheter ablation (CA) with left atrial appendage closure (LAAC) may produce comprehensive treatment for atrial fibrillation (AF) whereby rhythm control is achieved and stroke risk is reduced without the need for chronic oral anticoagulation. However, the efficacy and safety of this strategy is still controversial. Aim: To investigate the efficacy and safety of a combined CA with LAAC approach to treat AF in patients moderate-to-high-risk for bleeding. Methods: This meta-analysis was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Medline, Scopus, and Cochrane Central Register of Controlled Trials were systematically searched to identify relevant studies. Risk of bias was assessed using the Modified Newcastle-Ottawa scale and Cochrane risk of bias tool. Eligible studies reported outcomes in patients with AF who underwent combined CA and LAAC versus CA alone. Studies performing CA without pulmonary vein isolation were excluded. Results: Eight studies comprising 1878 patients were included (2 RCT, 6 observational). Pooled results showed no difference in arrhythmia recurrence (risk ratio [RR] 1.05; 95% confidence interval [CI] 0.84-1.30), stroke or systemic embolism (RR 0.71; 95% CI 0.26-1.94), total procedure time (mean difference 31.45 minutes; 95% CI -5.91-68.81), or major periprocedural complications (RR 1.28; 95% CI 0.28-5.89) when comparing combined CA and LAAC versus CA alone. Conclusion: Combined CA with LAAC for AF is associated with similar rates of arrhythmia free survival, stroke, major periprocedural complications, and procedure time when compared to CA alone. A combined strategy may be as safe and efficacious for patients moderate-to-high-risk for bleeding events to negate the need for chronic oral anticoagulation.

Abstract 4141438: Predictors of Left Atrial Low Voltage Areas Were Different among Age Groups in Patients with Atrial Fibrillation Ablation

Background: Catheter ablation is a well-established treatment for atrial fibrillation (AF). Left atrial low-voltage areas (LVAs) is associated with atrial remodeling following the progression of atrial cardiomyopathy, and poor rhythm outcome after catheter ablation. However, the predictors of LVAs presence have not been fully elucidated in different age groups. Purpose: The purpose of this study was to investigate predictors of the prevalence of LVAs in different age groups. Methods: 1,488 (age, 69 ± 10 years; female, 501 [34%]) consecutive patients who underwent initial ablation were included. Age groups were divided into three groups, namely <60 years old (younger age, n=272), 60-75 years old (intermediate age, n=864), ≥75 years old (older age, n=352). The definition of LVAs was areas with a bipolar voltage of <0.5 mV covering ≥5 cm2 of left atrial surface. Multivariate logistic regression analysis was performed to investigate the clinical predictors of LVAs. Results: Of 1,488 patients, LVAs existed in 352 (24%) patients. In the younger age group, C-reactive protein (odds ratio [OR], 4.5; [95% confidence interval {CI}: 1.5-13], p = 0.006) and previous history of heart failure (OR, 5.6; [95% CI: 1.2-26], p = 0.027) were the independent predictors of LVAs. In the intermediate age group, female (OR, 3.8; [95% CI: 2.6-5.7], p < 0.001), persistent AF (OR, 2.6; [95% CI: 1.7-4.1], p < 0.001), lower body mass index (OR, 0.93; [95% CI: 0.88-0.98], p = 0.004), lower hemoglobin (OR, 0.81; [95% CI: 0.72-0.93], p = 0.002), C-reactive protein (OR, 1.4; [95% CI: 1.0 1-2.0], p = 0.047), diabetes mellitus (OR, 1.8; [95% CI: 1.1-2,8], p = 0.01), left atrial diameter (OR, 1.04; [95% CI: 1.01-1.1], p = 0.007) were the independent predictors of LVAs. In the older age group, female (OR, 2.3; [95% CI: 1.4-3.7], p = 0.01), persistent AF (OR, 3.1; [95% CI: 1.8-5.2], p < 0.001) and lower hemoglobin (OR, 0.83; [95% CI: 0.71-0.97], p = 0.017) were the independent predictors of LVAs. Conclusion: In patients with atrial fibrillation ablation, the independent predictors of LVAs were different among age groups.

Abstract 4140117: A novel risk score predicts the prevalence of left atrial low-voltage areas and rhythm outcome in patients undergoing long-standing persistent atrial fibrillation ablation

Background: Catheter ablation is a most common treatment for atrial fibrillation (AF), but rhythm outcome after AF ablation in long-standing persistent atrial fibrillation (LS-PerAF) is still poor. Left atrial low-voltage areas (LVAs) is associated with poor rhythm outcome after catheter ablation. However, the predictors of LVAs presence have not been fully elucidated in patients with LS-PerAF. Purpose: The purpose of this study was to establish a novel predictive score for the prevalence of LVAs in patients with LS-PerAF ablation. Methods: In total, 109 consecutive patients who underwent initial ablation for LS-PerAF were included. LS-PerAF was defined as AF whose duration was more than 1 year. LVA was defined as areas with bipolar peak-to-peak voltage of < 0.50mV. A clinical risk score was obtained as the total number of independent predictors analyzed by multivariate logistic regression analysis. AF recurrence after the catheter ablation was followed for 24 months. Results: Of 109 patients with LS-PerAF, LVAs existed in 26 (24%) patients. A novel predictive score, named DESK score, consisted of diabetes mellitus (odds ratio [OR] 3.7, [95% confidence interval {CI} 2.2–11], p = 0.02), age ≥ 70 years (OR 3.8, [95% CI 1.4-10], p = 0.007), female sex (3.0 [95% CI 1.04-8.4], p = 0.04), AF duration ≥ 3.7 years (44 months) (OR 3.7, [95% CI 1.3-11], p =0.02). LVAs were more frequently found in patients with a higher DESK score (OR, 3.5 [95% CI, 1.9–6.5], p < 0.001) (Figure 1A). On receiver operating characteristic curve analysis, DESK score was a moderate predictor of LVAs presence (area under the curve, 0.750; Figure 1B). The optimal cut-off of DESK score was 3 points, corresponding to a 38.5% sensitivity, 97.6% specificity, and 83.5% predictive accuracy. Freedom from AF recurrence was significantly lower in patients with DESK score ≥ 3 than in those with DESK score < 3 (10.4% vs. 43.5%, p = 0.008). Conclusions: In patients who underwent LS-PerAF ablation, the DESK score correlated with the prevalence of LVAs, and associated with poor rhythm outcome.

Abstract 4145890: P-Wave Parameters on 12-Lead Electrocardiogram after Catheter Ablation: A Comparison between Pulsed Field Ablation and Cryoablation

Background: Catheter ablation (CA) is a well-established treatment for atrial fibrillation (AF). The most popular current methods of CA include radiofrequency ablation (RFA) and cryoablation (CRYO) which are thermal methods of ablation known to affect the autonomic nervous system through ablation of cardiac ganglionated plexi (GP). Pulsed[SC1] -field ablation (PFA) is a newer method of CA with demonstrated efficacy that preferentially affects cardiac cells and spares surrounding structures such as GP through irreversible electroporation which does not lead to chronic fibrosis like RFA or CRYO. Elevations in the marker the marker P terminal force (PTF) have been associated with AF/stroke and have been known to correlate with atrial fibrosis, and higher PTF after cryoablation for patients with paroxysmal AF has been associated with an increased risk of recurrence. The differences in P-wave parameters pre and post PFA have not been studied. Objective: To investigate the differences in P-wave parameters after PFA and compare them to CRYO. Methods: We identified 40 patients who underwent PFA (20 patients) or CRYO (20 patients) for paroxysmal AF and compared P-wave parameters including duration and amplitude in leads aVF, V1 and the PTF calculated as the duration x amplitude of the terminal negative component of the P-wave in V1. Data were obtained from 12-lead electrocardiograms obtained pre and post ablation. Results: The mean age of patients in our study was 61 with 75% male and 33% on antiarrythmics. We noticed a significant reduction in PTF for patients who underwent CRYO (54 mVmS at baseline compared to 36.8 mVmS after CRYO, p = 0.04) and no significant reduction in PTF for patients who underwent PFA (46 mVmS at baseline compared to 38 mVmS after PFA, p = 0.27). There was also a significant increase in HR after CRYO (65 bpm at baseline compared to 78 bpm after CRYO, p=0.01) and no significant change in HR after PFA (61 bpm at baseline compared with 60 bpm after PFA, p=0.8). There was no statistical difference in both groups looking at aVF or total V1 duration or amplitude pre and post ablation. Conclusions: CRYO leads to a significant change in PTF after ablation while PFA does not, consistent with the notion that PFA does not lead to fibrosis and PTF is not a useful marker for measuring risk of recurrence of AF post PFA.

Abstract 4141439: Catheter ablation and clinical outcomes among older Medicare beneficiaries with atrial fibrillation

Background: Catheter ablation (CA) is increasingly used for treatment of atrial fibrillation (AF). However, CA has not been widely adopted in the older population with AF. The aim of this study is to examine the risks of adverse outcomes following CA in older people with AF. Methods: Using 2014-2019 Medicare claims, we conducted a propensity score analysis of patients treated with CA within 6 months of new AF diagnosis to patients treated with only antiarrhythmic therapy in the 6-month period. The outcome follow-up began after the 6-month period. Cox proportional hazards models were used to estimate hazard ratios (HR) for the composite and individual endpoints from CABANA trial (death, stroke, major bleeding or cardiac arrest) and CASTLE-AF trial (death or heart failure). Subgroup analyses were performed by sex, race-ethnicity, social deprivation index, frailty and dementia. Results: The study population comprised of 14623 AF patients (mean age, 76.1±7.6 years; 55% female, 28% frailty, 13% dementia), including 8% receiving CA. The mean follow-up was 1.8 years. Compared to patients with only antiarrhythmic therapy, patients treated with CA had lower rates of CABANA endpoints (CA vs antiarrhythmic therapy: 5.6 vs 11.7 per 100 person-years; HR:0.72, 95%CI:0.66-0.77) and CASTLE-AF endpoints (6.5 vs 13.8 per 100 person-years; HR:0.72, 95%CI:0.67-0.78). The benefits of CA were consistent in both female and male for CABANA endpoints (female: HR:0.71, 95%CI:0.64-0.79 and male: HR:0.72, 95%CI:0.65-0.81) and CASTLE-AF endpoints (female: HR:0.65, 95%CI:0.59-0.73 and male: HR:0.78, 95%CI:0.71-0.87), and in both frail and non-frail patients for CABANA endpoints (frail: HR:0.72, 95%CI:0.66-0.80 and non-frail: HR:0.70, 95%CI:0.63-0.77) and CASTLE-AF endpoints (frail: HR:0.89, 95%CI:0.81-0.97 and non-frail: HR:0.69, 95%CI:0.63-0.75). Similar trends were observed for subgroups defined by race-ethnicity, social deprivation index, and dementia. Conclusions: These findings suggest that CA may be beneficial for older AF patients. Nonetheless, further investigation of the safety and efficacy of CA given to older patients in well-designed interventional trials are warranted.

Abstract 4137447: Length of WACA line Affects 1 st Pass Success rates in PVI

Background: Standard ablation for atrial fibrillation consists of wide antral pulmonary vein isolation, efficacy for which depends on a contiguous series of ablation lesions. The larger a circumference ablated around the pulmonary veins, the more challenging it may be to ensure durable isolation, due to technical and anatomic factors, which may in turn contribute to higher rates of atrial fibrillation (AF) recurrence. The relationship between WACA size and success rates may inform procedural methods and optimize outcomes. Objective: To examine the relationship between length of WACA lines and ablation success in patients that have undergone a PVI ablation. Methods: We performed a single-center, retrospective analysis of a consecutive series of 258 patients who underwent 1 st pulmonary vein isolation (PVI) for the treatment of atrial fibrillation, between 1/1/2022 and 6/30/2023. Radiofrequency ablation (RFA) was performed using 50 W with a contact-force sensing irrigated catheter. Information on acute 1 st pass success for left and right vein was recorded. The length of each WACA line was traced out manually, following the center of the ablated lesions. Follow up information consisted of AF recurrence at three, six, and twelve months. Student t-test was used for comparison of means and Chi-square test was used for categorical variables. Results: All veins were successfully isolated in all patients. WACA 1 st pass success rates were 87% in the left veins, and 83% in the right veins. Right WACA lines were generally longer. In patients with Left WACA 1 st pass success, the average length of the WACA line was 94.8cm, compared to 100.1cm in the group without 1 st pass success (p=0.025). In patients with right WACA 1 st pass success, the average length of the WACA line was 105.8cm, compared to 110.6cm in the group without 1 st pass success (p=0.07). When evaluating post PVI patients for recurrence of AF at 1year, there was a non-statistically significant association of AF recurrence with longer combined L+R WACA lines during index PVI (205.5cm vs 197.0cm, p=0.065). Conclusion: Longer WACA lines during index PVI are associated with failure of 1 st pass isolation. Further study is needed to address the mechanism by which longer WACA lines affect ablation efficacy, whether due to technical factors reflecting something intrinsic to underlying substrate.

Abstract 4124307: Outcome of Obesity in Atrial Fibrillation - Insights from The National Inpatient Sample Database

Background: Obesity is considered a significant risk factor for numerous cardiovascular conditions due to its effects on cardiac structure and function. The prevalence of atrial fibrillation (AF) is elevated among patients with obesity due to the dysregulation of several mechanisms. Weight loss has been shown to reverse cardiac remodeling, leading to a lower recurrence of AF despite the better prognosis in obese patients described as the obesity paradox. Methods: We utilized the National Inpatient Sample 2016-2019 to extract patients ≥18 years of age admitted with AF as the primary diagnosis based on ICD 10 codes. We performed univariate and multivariate regression analysis for known coronary risk factors. We divided patients based on their body mass index (BMI), and our primary outcomes were determining the odds of electrical cardioversion (ECV) and cardiac ablation (CA) due to AF. Results: The analysis included 1,625,809 weighted patients. Patients include underweight (6.66%), normal BMI (4.03), overweight (6.51%), obesity class I (20.65%), obesity class II (21.45%), and obesity class III (40.7). After multivariate regression analysis, patients with obesity class I, II, or III had higher odds of ECV, irrespectively of coronary risk factors (OR 1.3, 95% CI 1.25-1.37, OR 1.3, 95% CI 1.32-1.43, OR 1.3, 95% CI1.29-1.38, respectively, with statistically significant P values). However, underweight or normal BMI patients had fewer odds of ECV (OR 0.5 95%CI 0.49-0.61 and OR 0.6 95%CI 0.58-0.74, respectively, with P values <0.001). Meanwhile, there was no statistical significance between a BMI and the odds of CA. Conclusion: Our study highlights the significant impact of BMI on managing atrial fibrillation, particularly regarding electrical cardioversion (ECV). Patients in higher BMI categories (obesity class I, II, and III) demonstrated increased odds of undergoing ECV, suggesting that obesity may influence treatment approaches and outcomes in AF management. Interestingly, BMI did not affect the likelihood of cardiac ablation (CA), indicating a more complex relationship between body weight and AF treatment modalities that warrants further investigation. These findings underscore the importance of personalized treatment strategies to optimize outcomes, with a focus on weight management.

Abstract 4138212: Efficacy of Left Atrial Appendage Occlusion in Reducing Mortality and Major Bleeding Events in Cancer Patients with Atrial Fibrillation

Introduction: Atrial fibrillation (AF) is a common comorbidity in cancer patients, increasing their risk of stroke and mortality. Cancer patients are often excluded from anticoagulation and AF intervention trials due to the nature of their disease, and risk scores such as HAS-BLED, CHADS2/CHADS2-VASc often underpredict the high risk of AF and related complications for these patients. Research Question: Does left atrial appendage occlusion (LAAO) reduce mortality, major bleeding events (MBE), and stroke in cancer patients with AF? Methods: Using TriNetX, an international health research network with data from over 100 million patients, cancer patients with AF, with and without LAAO were identified between 2015 and 2022. Equal cohorts of 147 patients were created after propensity score matching for demographics, diabetes, hypertension, and heart failure. Measures of Association and Survival Analysis were conducted between 3-months and 5-years. The primary outcome was mortality. The secondary outcomes were MBE and stroke. Results: The study included 294 cancer patients with AF, with 147 having received LAAO. The risk of mortality at 3 months was 6.8% in the LAAO+ group compared to 15% in the LAAO- group (p-value= 0.025). At 6 months, the mortality risk was 8.8% in the LAAO+ group and 18.4% in the LAAO- group (p-value= 0.017). At 1 year, the mortality risk was 12.2% in the LAAO+ group and 23.8% in the LAAO- group (p-value=0.010). At 5 years, the mortality risk was 28.6% in the LAAO+ group and 49.7% in the LAAO- group (p-value<0.0001). The MBE risk was 20.4% for the LAAO+ group and 32% for the LAAO- group at 3 months (p-value= 0.024). At 6 months, the MBE risk was 25.9% in the LAAO+ group and 40.1% in the LAAO- group (p-value=0.009). Although there was no significant difference in risk of MBE at 1 year and 5 years, survival was higher among the LAAO+ group than the LAAO- group (64.92% vs 52.76%; p-value= 0.038 at 1 year and 52.67% vs 39.23%; p-value=0.029 at 5 years). However, there was no difference between stroke risk or survival probability across all measured time points. Conclusion: LAAO in cancer patients with AF was associated with significantly reduced mortality and major bleeding events over a 5-year period compared to those without LAAO. These findings suggest that LAAO may be a beneficial intervention for improving survival and reducing bleeding complications in cancer patients with AF.

PATHOPHYSIOLOGICAL AND STRUCTURAL PECULIARITIES OF CARDIAC FIBROSIS DEVELOPMENT IN ATRIAL FIBRILLATION

Introduction. In recent years, the study of the pathogenesis of atrial fibrillation (AF) and its complications resulting from this condition has drawn substantial attention from cardiologists. A comprehensive understanding of this issue is essential for investigating the structural and functional disturbances occurring in the heart during AF. These data are also important for developing novel therapies aimed at preventing the onset and progression of cardiac fibrosis. The aim of this study is to identify the primary pathways that activate cardiac connective tissue cells involved in fibrosogenesis, to examine the structural characteristics of this pathological process, and to investigate the role of fibroblasts in initiating and progressing cardiac fibrosis. Materials and Methods. The primary data for this article were collected through an in-depth analysis of recent scientific literature, with a focus on studies published in the last 5–7 years. Results. A detailed review of primary sources reveals that this cardiological issue has only been partially explored. Findings indicate a close link between the pathophysiological and structural mechanisms of AF and numerous resulting complications, with cardiac fibrosis being a primary consequence. Two major forms of fibrous damage to atrial cardiomyocytes play a key role in the development of cardiac fibrosis associated with AF. This includes both reactive and reparative types of cardiac fibrosis, which develop concurrently in atrial fibrillation. These structural changes lead not only to damage and loss of cardiomyocytes but also to pathological remodeling of fibroblasts, the intercellular matrix, and the atria and ventricles. Disruptions in bioelectrical potential conduction are also observed. Activated fibroblasts play a central role in initiating cardiac fibrosis, with key stages of protein synthesis involved in atrial fibrosis now better understood. Specific intracellular signaling pathways, which present potential therapeutic targets for preventing cardiac fibrosis in AF treatment, have been identified. Conclusion. Atrial fibrillation and cardiac fibrosis are interdependent, with each potentially accelerating the progression of the other. These pathological processes are underpinned by significant structural and functional disruptions within cardiac cells and the intercellular matrix. Fibroblasts, myofibroblasts, and intensive fibrous tissue formation within the matrix are pivotal in the development of cardiac fibrosis. A preventive strategy targeting early intervention in cardiac fibrosis shows the greatest therapeutic promise.

Case Report: One-stop procedure for atrial fibrillation patients with dextrocardia

We present the case of an elderly woman with congenital dextrocardia who experienced severe palpitations. An electrocardiogram revealed paroxysmal atrial fibrillation, and her medical history unveiled cerebral infarction and renal failure. In the treatment of paroxysmal atrial fibrillation, anticoagulation is a key requirement. Although non-vitamin K antagonist oral anticoagulants are recommended by guidelines, their efficacy is compromised in patients undergoing dialysis due to renal metabolism. In addition, warfarin may cause fluctuations in international normalized ratio, which is not conducive to controlling symptoms of cerebral infarction. To improve the patient's quality of life, we focused on addressing the unique challenges posed by dextrocardia in a one-stop procedure.

Update atrial fibrillation in older adults

Atrial fibrillation is the most frequent cardiac arrhythmia in old age. As aresult of the positive data on ablation, the focus has shifted to rhythm control. Older adults can also benefit from catheter ablation. Oral anticoagulation remains an essential part of the pharmacological treatment of atrial fibrillation. Recent study results show that geriatric patients require an individual treatment approach, which should be based on the recommendations of the current guidelines and the use of supplementary aids. The assessment of functionality should be taken into account in the treatment and the treatment goal planning as well as symptoms associated with atrial fibrillation. In acute situations cardioversion and long-term drug or interventional (catheter ablation) rhythm-stabilizing treatment are available for rhythm control.

Catheter Ablation of Atrial Fibrillation in Infiltrative Cardiomyopathies: A Narrative Review.

Atrial and ventricular arrhythmias are common in patients with Infiltrative heart diseases. This review discusses ablative techniques for arrhythmias in amyloidosis, sarcoidosis, hemochromatosis, and glycogen storage disorders, primarily focusing on atrial fibrillation (AF). A thorough literature review was conducted on the MEDLINE database to synthesize current knowledge and propose future research directions. AF is the most common arrhythmia identified in patients with amyloidosis due to cellular infiltration and atrial dilation. While catheter ablation is associated with a significantly lower rate of all-cause mortality and admission rate, conflicting data exist regarding the higher risk of pericardial effusion, in-hospital mortality, length of stay, and cost of hospitalization. Cardiac sarcoid predisposes AF due to granulomas, atrial dilation, and scarring. Studies demonstrate encouraging outcomes and low recurrence rates in these patients who undergo ablation for AF, with no difference in complications compared to those without sarcoidosis. AF is the most common arrhythmia in hereditary hemochromatosis (HH), secondary to increased myocardial iron stores and elevated oxidative stress, and is primarily managed by chelation. Scant reports regarding ablation are described for HH and glycogen storage disorders. Catheter ablation is a safe and effective modality for the treatment of AF in infiltrative cardiomyopathy. Future large-scale trials are needed to confirm these findings.

Temperature guided high and very high-power short duration ablation for atrial fibrillation treatment - The peQasus multicentre study.

Temperature-controlled high-power short-duration (HPSD) radiofrequency catheter ablation for pulmonary vein isolation (PVI) utilizing a novel ablation catheter (QDOT Micro) with real-time assessment of catheter tip temperature aims for safer, more effective and faster procedures. The peQasus study is a large European multicenter study set up to assess safety, acute efficacy and outcomes of temperature-controlled HPSD based PVI. The primary endpoints were safety, efficacy and 12-months freedom from atrial tachyarrhythmias. Additionally, two strategies namely very HPSD (90W for 4 seconds) only and a hybrid approach (HPSD with maximum of 50W and vHPSD) were compared. A total of 1,023 AF patients in 15 centers from 9 European countries received PVI with the QDOT. Complete PVI was successfully achieved in all patients. In 699/1023 (68.3%) the vHPSD only approach (vHPSD group) and in 324/(31.7%) patients the hybrid approach (hybrid group) was utilized. The mean procedure duration was 98.4±37.4 min (vHPSD: 88.2±34.9min, hybrid: 117.4±32.7min, p<0.001). The first pass isolation rate of all PVs was 64% (vHPSD: 62.6%, hybrid: 67.1%, p=0.187). Severe adverse events were observed in 1.7% (vHPSD: 1.6%, hybrid: 1.9%, p=0.746). 12-month arrhythmia-recurrence free survival was 77.1% (vHPSD: 76.8%, hybrid: 77.8%, p=0.241). In this large multicentre study temperature-controlled HPSD and vHPSD ablation via a novel ablation catheter provides safe and effective PVI with a relatively short procedure duration. Despite a shorter procedure time no differences in terms of safety and freedom from arrhythmia-recurrence were found irrespective of utilizing vHPSD or the hybrid approach.

Atrial Fibrillation in Patients with Very High Risk for Stroke and Adverse Events—Insights from the Observational ARENA Study

Background: Atrial fibrillation (AF) is a major cause of stroke. An individual risk estimation remains challenging, as AF patients with and without cerebrovascular event (CVE) may differ in yet unknown factors beyond those covered by the CHA2DS2-VASc score. We aimed to identify differences between AF patients with and without CVE with regard to AF characteristics and treatment, vascular risk factors and comorbidities, prognosis and outcome. Methods: We analyzed patients included in the Atrial Fibrillation Rhine-Neckar Region (ARENA) Project, an observational cohort study of patients with AF. Patients were recruited by their general practitioner or during a hospital stay and were divided into two groups for the present analysis: patients with acute CVE at baseline and/or history of CVE versus patients without CVE. Follow-up at 1 year was conducted via phone call. Results: Of 2061 included patients (60.6% male), 292 (14.2%) belonged to the CVE group. Patients in the CVE group were older (mean age 74.6 versus 71.7 years; p &lt; 0.001) and had a higher CHA2DS2-VASc score at baseline (5.3 versus 3.3 points; p &lt; 0.001) based on the preceding CVE. Moreover, patients with either acute or chronic CVE had a larger left atrium (median diameter 47/46 mm versus 44 mm; p = 0.001). Patients with acute CVE had structural heart diseases (p &lt; 0.001) less frequently than patients with previous or without CVE. Mortality at 1 year (HR 1.95; 95%-CI 1.37–2.78) was more frequent in the CVE group (p &lt; 0.001). During 1-year of follow-up, stroke occurred more frequently in survivors with CVE (2.9% versus 0%; p &lt; 0.001). Conclusions: AF patients with CVE have a significantly worse prognosis than AF patients without CVE. Atrial structural remodeling, underlying cardiovascular disease, stroke-induced heart injury and further unidentified factors may account for this finding. Characterization of AF patients including echocardiography to detect atrial structural remodeling may be helpful in risk stratification beyond classical scores.

Atrial fibrillation – a comparative review of one of the most common arrhythmias in dogs and humans

Atrial fibrillation is the most prevalent arrythmia in dogs and humans and is characterised by chaotic depolarisation of the atria, resulting in damage to the atrial myocardium. It can lead to heart failure or worsen an existing condition and cause sudden death. Electrocardiographically, atrial fibrillation is characterised by the absence of P waves and an irregularly irregular rhythm, with narrow QRS complexes. Treatment of atrial fibrillation requires knowledge of pathophysiology and the pharmacology of antiarrhythmic drugs. In contrast to human medicine, the treatment of dogs revolves mainly around rate control strategies, although new studies propose the consideration of several rhythm strategies. Considering the complexity of atrial fibrillation, there is strong need for a consensus on classification, diagnosis and treatment in dogs.

Pathophysiology, molecular mechanisms, and genetics of atrial fibrillation.

The development of atrial fibrillation (AF) is a highly complex, multifactorial process involving pathophysiologic mechanisms, molecular pathway mechanisms and numerous genetic abnormalities. The pathophysiologic mechanisms including altered ion channels, abnormalities of the autonomic nervous system, inflammation, and abnormalities in Ca2 + handling. Molecular pathway mechanisms including, but not limited to, renin-angiotensin-aldosterone (RAAS), transforming growth factor-β (TGF-β), oxidative stress (OS). Although in clinical practice, the distinction between types of AF such as paroxysmal and persistent determines the choice of treatment options. However, it is the pathophysiologic alterations present in AF that truly determine the success of AF treatment and prognosis, but even more so the molecular mechanisms and genetic alterations that lie behind them. One tiny clue reveals the general trend, and small beginnings show how things will develop. This article will organize the development of these mechanisms and their interactions in recent years.

Lipid-lowering drugs, circulating inflammatory factors, and atrial fibrillation: a mediation Mendelian randomization study

BackgroundPrevious studies have shown an association between lipid-lowering drugs, circulating inflammatory factors, and atrial fibrillation (AF), but the specific effects of lipid-lowering drugs on AF and whether they can be mediated by circulating inflammatory factors remain unclear.MethodsWe collected 10 genetic variants encoding lipid-lowering drug targets (LDLR, HMGCR, PCSK9, NPC1L1, APOB, APOB, ABCG5, ABCG8, LPL, APOC3, and PPARA) and AF based on genome-wide association study (GWAS) summary statistics. Drug target Mendelian randomization (MR) was used to explore the causal relationship between lipid-lowering drugs and AF. In addition, we performed a mediation analysis of 91 circulating inflammatory factors to explore potential mediators. Sensitivity analyses were performed to verify the reliability of the MR Results by MR-Egger intercept test, Cochran's Q test and leave-one-out test.ResultsThe results of IVW method showed that LPL agonist had a protective effect on AF(OR = 0. 854, 95%CI: 0.816–0.894, P = 1.844E-11). However, the other nine lipid-lowering drug targets had no significant effect on AF. Notably, we found a mediator role of Fibroblast Growth Factor 5 (FGF5) in the protective effect of LPL agonist on AF with a mediator ratio of 9.22%. Sensitivity analyses supported the robustness of our findings, indicating a possible mediating pathway by which LPL agonists affect the risk of AF.ConclusionOur study provides new insights into the complex interactions among lipid-lowering agents, circulating inflammatory factors and AF, and also identified a potential mediating role of FGF5 in the pathogenesis of AF. Our findings highlight the potential of LPL agonists and targeting specific inflammatory factors for therapeutic intervention in AF, providing promising avenues for future research and clinical strategies for the management and prevention of AF.