Sex-Related Differences in Atrial Remodeling in Patients With Atrial Fibrillation: Relationship to Ablation Outcomes

Differential hemodynamic adaptations to tilt test in patients with idiopathic atrial fibrillation

The hemodynamic response during the transition from the supine to standing position in idiopathic atrial fibrillation (AF) patients is not completely understood. This study aimed to analyze the hemodynamic changes that occur during the head-up tilt test in idiopathic AF patients. We investigated the hemodynamic changes during the head-up tilt test with impedance cardiography in 40 AF patients (12 with AF rhythm-AFr and 28 with sinus rhythm-AFsr) and 38 non-AF controls. Patients with AFr had attenuated SVI decrease after standing when compared to AFsr and non-AF [ΔSVI in mL/m2: -1.3 (-3.4 to 1.7) vs. -6.4 (-17.3 to -0.1) vs. -11.8 (-18.7 to -8.0), respectively; p < 0.001]. PVRI decreased in AFr but increased in AFsr and non-AF [ΔPVRI in dyne.seg.m2/cm5: -477 (-1148 to 82.5) vs. 131 (-525 to 887) vs. 357 (-29 to 681), respectively; p < 0.01]. Similarly, compared with non-AF patients, AFr patients also had a greater HR and greater CI increase after standing. The haemodynamic response to orthostatic challenge suggests differential adaptations between patients with AF rhythm and those reverted to sinus rhythm or healthy controls. Characterizing the hemodynamic phenotype may be relevant for the individualized treatment of AF patients.

Characterization of patients with extensive left atrial myopathy referred for atrial fibrillation ablation: incidence, predictors, and outcomes

BACKGROUND

Although atrial fibrosis has a relevant impact on ablation success rate, experimental studies have reported that extensive fibrosis may be accompanied by a reduced burden secondary to a prominent depression of atrial excitability.

OBJECTIVES

We aimed to identify clinical and echocardiographic factors associated with extensive left atrial myopathy (ELAM), to analyze the predictive ability of established scores (AF score, APPLE, and DR-FLASH) and assess outcomes in terms of AF recurrence, left atrial flutter, and post-procedural heart failure admissions.

METHODS

A total of 950 consecutive patients undergoing the first AF ablation were included. A 3D electroanatomical mapping system (CARTO3, Biosense Webster) was created using a multipolar mapping catheter (PentaRay, Biosense Webster). ELAM was defined as ≥ 50% low voltage area. A subanalysis with four groups was also created (< 10%; 10-20%; 10-20%; and > 30%). Logistic regressions, Cox proportional hazards models, and log-rank test were used to test the predictors independently associated with the presence of ELAM and AF recurrence. The model was prospectively validated in a cohort of 150 patients obtaining an excellent ability for prediction AUC 0.90 (CI 95% 0.84-0.96).

RESULTS

Overall, 78 (8.42%) presented ELAM. Age, female sex, persistent AF, first-degree AV block, and E/e' were significant predictors. The model incorporating these factors outperformed the existing scores (AUC = 0.87). During a mean follow-up of 20 months (IQR 9 to 36), patients with ELAM presented a higher rate of AF recurrence (42.02% vs 26.01%, p = 0.030), left atrial flutter (26.03% vs 8.02%, p < 0.001), and post-procedural heart failure admissions (12.01% vs 0.61%, p < 0.001) than non-ELAM patients.

CONCLUSIONS

This study reveals the incidence and clinical factors associated with ELAM in AF, highlighting age, female, persistent AF, first-degree AV block, and E/e'. Importantly, the presence of ELAM is associated with poorer outcomes in terms of recurrence and HF admission.

Soluble ST2 is associated with postoperative atrial fibrillation after cardiac surgery in postmenopausal women

BACKGROUND

Postoperative atrial fibrillation (POAF) represents the most common complication following cardiac surgery. Approximately one-third of patients experiencing POAF transition to atrial fibrillation within a year, challenging the notion of POAF as merely a transient event. Soluble ST2 (sST2) is an established biomarker regarding fibrosis and myocardial stretch, however, its role in predicting the onset of POAF remains unclear.

METHODS

Preoperative sST2 levels have been assessed in 496 individuals with no prior history of AF who underwent elective cardiac surgery, including valve, coronary artery bypass graft surgery, or a combined procedure.

RESULTS

The average age was 70 years, and 29.4 % were female. Overall, 42.3 % developed POAF. sST2 levels were found to be significantly higher in patients with POAF. Interestingly, sST2 was only predictive of POAF in females with an adjusted OR of 1.894 (95 %CI:1.103-3.253; p = 0.021) and not males (OR:1.091; 95 %CI:0.849-1.402; p = 0.495). Furthermore, within a linear regression model it was observed that for every 1 ng/mL increase in sST2 levels, the average POAF duration extended by 39.5 min (95 %CI:15.8-63.4 min; p = 0.001).

CONCLUSION

sST2 predicts the onset of POAF in women but not men undergoing cardiac surgery. Furthermore, sST2 levels were associated with the subsequent burden of POAF. Thus, assessment of sST2 in addition to clinical risk factors could improve risk stratification for development of POAF following elective cardiac surgery.

Patient-specific left atrium contraction quantification associated with atrial fibrillation: A region-based approach

BACKGROUND AND OBJECTIVES

Atrial fibrillation (AF) is a widespread cardiac arrhythmia that significantly impacts heart function. AF disrupts atrial mechanical contraction, leading to irregular, uncoordinated, and slow blood flow inside the atria which favors the formation of clots, primarily within the left atrium (LA). A standardized region-based analysis of the LA is missing, and there is not even any consensus about how to define the LA regions. In this study we propose an automatic approach for regionalizing the LA into segments to provide a comprehensive 3D region-based LA contraction assessment. LA global and regional contraction were quantified in control subjects and in AF patients to describe mechanical abnormalities associated with AF.

METHODS

The proposed automatic approach for LA regionalization was tested in thirteen control subjects and seventeen AF patients. After dividing LA into standard regions, we evaluated the global and regional mechanical function by measuring LA contraction parameters, such as regional volume, global and regional strains, regional wall motion and regional shortening fraction.

RESULTS

LA regionalization was successful in all study subjects. In the AF group compared with control subjects, results showed: a global impairment of LA contraction which appeared more pronounced along radial and circumferential direction; a regional impairment of radial strain which was more pronounced in septal, inferior, and lateral regions suggesting a greater reduction in mechanical efficiency in these regions in comparison to the posterior and anterior ones.

CONCLUSION

An automatic approach for LA regionalization was proposed. The regionalization method was proved to be robust with several LA anatomical variations and able to characterize contraction changes associated with AF.

Predictors of low-voltage zones in patients with persistent atrial fibrillation eligible for catheter ablation: An observational study

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 <0.5 mV.

RESULTS

The mean age of the cohort was 65.3 ± 8.6 years and 26.4% were female. Additionally, 25.7% had significant LVZs, most frequently located in the anterior wall of the LA. Multivariable analysis identified the following independent predictors for LVZ: advanced age (OR [odds ratio] = 1.08, 95% CI [confidence interval] = 1.03-1.13, 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.

Sex-Based Mechanisms of Cardiac Development and Function: Applications for Induced-Pluripotent Stem Cell Derived-Cardiomyocytes

Males and females exhibit intrinsic differences in the structure and function of the heart, while the prevalence and severity of cardiovascular disease vary in the two sexes. However, the mechanisms of this sex-based dimorphism are yet to be elucidated. Sex chromosomes and sex hormones are the main contributors to sex-based differences in cardiac physiology and pathophysiology. In recent years, the advances in induced pluripotent stem cell-derived cardiac models and multi-omic approaches have enabled a more comprehensive understanding of the sex-specific differences in the human heart. Here, we provide an overview of the roles of these two factors throughout cardiac development and explore the sex hormone signaling pathways involved. We will also discuss how the employment of stem cell-based cardiac models and single-cell RNA sequencing help us further investigate sex differences in healthy and diseased hearts.

Enhanced Ca2+-Driven Arrhythmias in Female Patients with Atrial Fibrillation: Insights from Computational Modeling

BACKGROUND AND AIMS

Substantial sex-based differences have been reported in atrial fibrillation (AF), with female patients experiencing worse symptoms, increased complications from drug side effects or ablation, and elevated risk of AF-related stroke and mortality. Recent studies revealed sex-specific alterations in AF-associated Ca2+ dysregulation, whereby female cardiomyocytes more frequently exhibit potentially proarrhythmic Ca2+-driven instabilities compared to male cardiomyocytes. In this study, we aim to gain a mechanistic understanding of the Ca2+-handling disturbances and Ca2+-driven arrhythmogenic events in males vs females and establish their responses to Ca2+-targeted interventions.

METHODS AND RESULTS

We incorporated known sex differences and AF-associated changes in the expression and phosphorylation of key Ca2+-handling proteins and in ultrastructural properties and dimensions of atrial cardiomyocytes into our recently developed 3D atrial cardiomyocyte model that couples electrophysiology with spatially detailed Ca2+-handling processes. Our simulations of quiescent cardiomyocytes show increased incidence of Ca2+ sparks in female vs male myocytes in AF, in agreement with previous experimental reports. Additionally, our female model exhibited elevated propensity to develop pacing-induced spontaneous Ca2+ releases (SCRs) and augmented beat-to-beat variability in action potential (AP)-elicited Ca2+ transients compared with the male model. Parameter sensitivity analysis uncovered precise arrhythmogenic contributions of each component that was implicated in sex and/or AF alterations. Specifically, increased ryanodine receptor phosphorylation in female AF cardiomyocytes emerged as the major SCR contributor, while reduced L-type Ca2+ current was protective against SCRs for male AF cardiomyocytes. Furthermore, simulations of tentative Ca2+-targeted interventions identified potential strategies to attenuate Ca2+-driven arrhythmogenic events in female atria (e.g., t-tubule restoration, and inhibition of ryanodine receptor and sarcoplasmic/endoplasmic reticulum Ca2+-ATPase), and revealed enhanced efficacy when applied in combination.

CONCLUSIONS

Our sex-specific computational models of human atrial cardiomyocytes uncover increased propensity to Ca2+-driven arrhythmogenic events in female compared to male atrial cardiomyocytes in AF, and point to combined Ca2+-targeted interventions as promising approaches to treat AF in female patients. Our study establishes that AF treatment may benefit from sex-dependent strategies informed by sex-specific mechanisms.

Probability Score to Predict Spontaneous Conversion to Sinus Rhythm in Patients with Symptomatic Atrial Fibrillation When Less Could Be More?

Background: The probability of spontaneous conversion (SCV) to sinus rhythm (SR) in patients presenting to the emergency department (ED) with hemodynamically stable, symptomatic atrial fibrillation (AF) is not well known. Objective: To develop and validate a score to determine the probability of SCV to SR in patients presenting to the ED with hemodynamically stable, symptomatic AF. Methods: This retrospective, observational study enrolled consecutive patients admitted with AF to the ED. Variables associated to SCV during a 6 h "wait-and-see" approach were used to develop and validate a score to determine the probability of SCV to SR in AF patients. The study was divided in two phases: (1) score development and (2) validation of the predictive score. Results: Out of 748 eligible patients, 446 patients were included in the derivation cohort, whereas 302 patients were included in the validation cohort. In the derivation cohort, based on multivariable logistic analysis, a probability score weight was developed including: previous SCV (3 points), AF-related symptom duration < 24 h (5 points), age ≥ 65 years (3 points) and female sex (2 points). The score allowed us to divide patients in three groups based on the probability of SCV to SR during the 6 h observation period. The probability prediction model showed an area under the curve (AUC) of 0.707 and 0.701 in the derivation and validation cohorts, respectively. Conclusions: The proposed score allowed us to predict SCV probability with good accuracy and may help physicians in tailoring AF management in an effective and timely manner.

Impact of diagnosis-to-ablation time on clinical outcomes in patients with early-onset atrial fibrillation

BACKGROUND

Evidence was lacking for the early choice of radiofrequency ablation (RFA) among patients with early-onset atrial fibrillation (AF).

HYPOTHESIS

This study aimed to explore whether earlier RFA was associated with better clinical outcomes among early-onset AF patients.

METHODS

Patients, who were diagnosed with AF before 45 years and underwent their first RFA procedures at baseline of the China Atrial Fibrillation registry, were enrolled and divided into four diagnosis-to-ablation time (DAT) groups: DAT ≤ 1 year, 1 year < DAT ≤ 3 years, 3 years < DAT ≤ 6 years, and DAT > 6 years. Another group of nonablation patients, who were newly diagnosed with AF and younger than 45 years, were also included. Adjusted associations of groups with composite cardiovascular events (cardiovascular death, embolism, major hemorrhages, or cardiac rehospitalization) or recurrent AF were analyzed using Cox proportional hazards models.

RESULTS

Among 1694 patients who underwent their first RFA at enrollment, incidences of composite cardiovascular outcomes were increasing with extension of DAT (DAT ≤ 1 year: 6.1/100 person-years, 1 year < DAT ≤ 3 years: 7.9/100 person-years, 3 years < DAT ≤ 6 years: 7.6/100 person-years, DAT > 6 years: 10.5/100 person-years; p < .001). In comparison with DAT > 6 years group, the DAT ≤ 1 year group was associated with reduced risk of cardiovascular events (adjusted hazard ratio, HR [95% confidence interval, CI] = 0.64 [0.47-0.87], p = .005) and AF recurrence (adjusted HR [95% CI] = 0.70 [0.57-0.88], p = .002). Associations remained similar after stratified by AF types. Compared to nonablation group (n = 413), DAT ≤ 1year patients tended to show lower cardiovascular risk (adjusted HR [95% CI] = 0.78 [0.58-1.05], p = .099) and lower risk of recurrent AF (adjusted HR [95% CI] = 0.46 [0.38-0.55], p < .001).

CONCLUSIONS

A shorter DAT was associated with a lower risk of cardiovascular events and recurrent AF for early-onset AF patients.

Association of Preablation Plasma Corin Levels With Atrial Fibrillation Recurrence After Catheter Ablation: A Prospective Observational Study

BACKGROUND

We assessed the impact of pre- and postprocedural plasma corin levels on the recurrence of atrial fibrillation (AF) after catheter ablation (CA).

METHODS AND RESULTS

This prospective, single-center, observational study included patients undergoing their first CA of AF. Corin was measured before and 1 day after CA. The primary end point was recurrent AF between 3 and 12 months after ablation. From April 2019 through May 2021, we analyzed 616 patients with AF (59.09% men) with a mean age of 62.86±9.42 years. Overall, 153 patients (24.84%) experienced recurrent AF. In the recurrence group, the pre- and postprocedure corin concentrations were 539.14 (329.24-702.08) and 607.37 (364.50-753.80) pg/mL, respectively, which were significantly higher than the nonrecurrence group's respective concentrations of 369.05 (186.36-489.28) and 489.12 (315.66-629.05) pg/mL (both P<0.0001). A multivariate Cox regression analysis with confounders found that elevated preablation corin levels were significantly associated with an increased risk of AF recurrence after CA. Receiver operating characteristic curve analysis identified that a preablation corin threshold of >494.85 pg/mL predicted AF recurrence at 1 year. An increase of 1 SD in corin concentrations before CA (264.94 pg/mL) increased the risk of recurrent AF by 54.3% after adjusting for confounding variables (hazard ratio, 1.465 [95% CI, 1.282-1.655]; P<0.0001).

CONCLUSIONS

Plasma corin levels at baseline is a valuable predictor of AF recurrence after CA, independent of established conventional risk factors. Risk stratification before ablation for AF may be useful in selecting treatment regimens for patients.

Clinical Outcomes by Sex After Pulsed Field Ablation of Atrial Fibrillation

Importance

Previous studies evaluating the association of patient sex with clinical outcomes using conventional thermal ablative modalities for atrial fibrillation (AF) such as radiofrequency or cryoablation are controversial due to mixed results. Pulsed field ablation (PFA) is a novel AF ablation energy modality that has demonstrated preferential myocardial tissue ablation with a unique safety profile.

Objective

To compare sex differences in patients undergoing PFA for AF in the Multinational Survey on the Methods, Efficacy, and Safety on the Postapproval Clinical Use of Pulsed Field Ablation (MANIFEST-PF) registry.

Design, Setting, and Participants

This was a retrospective cohort study of MANIFEST-PF registry data, which included consecutive patients undergoing postregulatory approval treatment with PFA to treat AF between March 2021 and May 2022 with a median follow-up of 1 year. MANIFEST-PF is a multinational, retrospectively analyzed, prospectively enrolled patient-level registry including 24 European centers. The study included all consecutive registry patients (age ≥18 years) who underwent first-ever PFA for paroxysmal or persistent AF.

Exposure

PFA was performed on patients with AF. All patients underwent pulmonary vein isolation and additional ablation, which was performed at the discretion of the operator.

Main Outcomes and Measures

The primary effectiveness outcome was freedom from clinically documented atrial arrhythmia for 30 seconds or longer after a 3-month blanking period. The primary safety outcome was the composite of acute (<7 days postprocedure) and chronic (>7 days) major adverse events (MAEs).

Results

Of 1568 patients (mean [SD] age, 64.5 [11.5] years; 1015 male [64.7%]) with AF who underwent PFA, female patients, as compared with male patients, were older (mean [SD] age, 68 [10] years vs 62 [12] years; P < .001), had more paroxysmal AF (70.2% [388 of 553] vs 62.4% [633 of 1015]; P = .002) but had fewer comorbidities such as coronary disease (9% [38 of 553] vs 15.9% [129 of 1015]; P < .001), heart failure (10.5% [58 of 553] vs 16.6% [168 of 1015]; P = .001), and sleep apnea (4.7% [18 of 553] vs 11.7% [84 of 1015]; P < .001). Pulmonary vein isolation was performed in 99.8% of female (552 of 553) and 98.9% of male (1004 of 1015; P = .90) patients. Additional ablation was performed in 22.4% of female (124 of 553) and 23.1% of male (235 of 1015; P = .79) patients. The 1-year Kaplan-Meier estimate for freedom from atrial arrhythmia was similar in male and female patients (79.0%; 95% CI, 76.3%-81.5% vs 76.3%; 95% CI, 72.5%-79.8%; P = .28). There was also no significant difference in acute major AEs between groups (male, 1.5% [16 of 1015] vs female, 2.5% [14 of 553]; P = .19).

Conclusion and Relevance

Results of this cohort study suggest that after PFA for AF, there were no significant sex differences in clinical effectiveness or safety events.

Sex differences in characteristics of atrial fibrillation recurrence post surgical pulmonary vein isolation

Background

Prior studies demonstrated that female sex is associated with arrhythmia recurrence after endovascular pulmonary vein isolation (PVI). However, it is unknown if the sexes differ in outcome after video assisted thoracoscopic (VATS) PVI. The aim of this study was therefore to compare characteristics of recurrent AF episodes in a matched male and female population, using implantable loop recorders for continuous rhythm monitoring.

Methods

40 matched (based on propensity score) males (age: 60.0 ± 7.71 (45-75)) and females (age: 62.0 ± 7.0 (37-74)) were retrieved from an existing database from a prior conducted study by the cardiothoracic department of the OLVG hospital (1) containing patients who received an implantable looprecorder and underwent a VATS PVI between 2012 and 2017. Patients were continuously monitored for a period of 12 months after VATS PVI and AF characteristics were compared.

Results

An equal number of males and females had AF episodes during all periods (P > 0.05). The number of AF episodes was higher in females, during the first 6 months (P = 0.01, P = 0.034). During the entire follow up, the total AF duration was longer in females (P = 0.01, for all periods) with shorter inter - episode intervals (P = 0.001, P = 0001, P = 0.04) and a higher AF burden (P = 0.003, P = 0001, P = 0.006). After 3 months, AF recurrences during the night were more frequently observed in female patients (P = 0.001, P = 0.001).

Conclusions

AF episodes occur frequently in both sexes after VATS PVI and warrant frequent rhythm monitoring. The observed sex differences in AF burden after VATS PVI, calls for intensive rhythm monitoring and aggressive treatment of recurrent AF epsiodes in females.

Gender-Related Differences in Atrial Substrate in Patients with Atrial Fibrillation

Gender-related differences have been reported in patients who underwent pulmonary vein isolation (PVI). Atrial substrate plays a role in the outcomes after ablation but gender-related differences in atrial substrate have never been described in detail. We sought to analyze gender-related differences in atrial remodeling (spontaneous low-voltage zones [LVZs]) and their clinical relevance after PVI. We conducted a prospective multicenter study, including consecutive patients who underwent first PVI-only atrial fibrillation (AF) ablation. LVZs were analyzed on high-density electroanatomical maps collected with multipolar catheter, before PVI. In total, 262 patients (61 ± 11 years, 31% female, 50% persistent AF) were followed for 28 months. In women, LVZs were larger (10% vs 4% of left atrial surface [p <0.001]) and female gender was independently associated with fourfold higher risk of having advanced (LVZ > 15%) atrial remodeling (odds ratio 4.56, p <0.001). AF recurrence-free survival was not different between men and women (log-rank p = 0.2). Although LVZs were independently associated higher AF recurrences at multivariate analysis (hazard ratio [HR] 1.2, p = 0.038), female gender was not (HR 1.4, p = 0.211). Specifically, the LVZ cutoff to predict outcomes was different in men and women: >5% in men (HR 3.0, p <0.001), >15% in women (HR 2.7, p = 0.02). In conclusion, women have more widespread LVZ in all left atrial regions. Despite more extensive atrial remodeling, the AF recurrence rate is similar in men and women, and LVZs become prognostic in women only at high burden (>15%). LVZs seem to have a different prognostic role in men and women.

Sex-related differences in the impact of nutritional status on length of hospital stay in atrial fibrillation: a retrospective cohort study

Background

Nutritional status is related to the length of hospitalization of patients with atrial fibrillation (AF). The aim of this study is to assess the prognostic impact of nutritional status and body mass index on length of hospital stay (LOHS) among patients with AF relative to their sex.

Methods

A retrospective analysis of the medical records of 1,342 patients admitted urgently with a diagnosis of AF (ICD10: I48) to the Cardiology Department (University Hospital in Wroclaw, Poland) between January 2017 and June 2021.

Results

In the study group, women were significantly older than men (72.94 ± 9.56 vs. 65.11 ± 12.68, p < 0.001). In an unadjusted linear regression model, malnutrition risk was a significant independent predictor of prolonged hospitalization in men (B = 1.95, p = 0.003) but not in women. In the age-adjusted linear regression model, malnutrition risk was a significant independent predictor of prolonged hospitalization in men (B = 1.843, p = 0.005) but not in women. In the model adjusted for age and comorbidities, malnutrition risk was a significant independent predictor of prolonged hospitalization in men only (B = 1.285, p = 0.043). In none of the models was BMI score a predictor of LOHS in either sex.

Conclusion

The risk of malnutrition directly predicts the length of hospital stays in men but not women. The study did not find a relationship between body mass index and length of hospital stay in both women and men.

Sex Differences in Atrial Fibrillation

PURPOSE OF REVIEW

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. The estimated lifetime risk of developing AF is higher in men; however, due to differences in life expectancy, the overall prevalence is higher among women, particularly in the older age group. Sex differences play an important role in the pathophysiology, presentation, and clinical outcomes of AF. Awareness of these differences minimizes the potential for disparities in AF management. Our review summarizes the current literature on sex differences in AF, including the epidemiology, pathophysiology, risk factors, clinical symptomatology, mechanisms, treatment, and outcomes. We also explore the implications of these differences for clinical practice and future research.

RECENT FINDINGS

Women are more likely to present with atypical symptoms, have a higher stroke risk, and have a worse quality of life with AF when compared to men. Despite this, they are less likely to receive rhythm control strategies and anticoagulants. The sex-based differences in AF pathology and management might be a combination of inherent biological and hormonal differences, and implicit bias of the research entities and treating clinicians. Our review stresses the need for further sex-specific research in the pathophysiology of AF and opens a dialogue on personalized medicine, where management strategies can be tailored to individual patient characteristics, including sex.

Impact of gender on left atrial low-voltage zones in patients with persistent atrial fibrillation: results of a voltage-guided ablation

Background

Gender-related differences have been reported in atrial fibrotic remodeling and prognosis of atrial fibrillation (AF) patients after ablation. We assessed in persistent AF the regional distribution of left atrial (LA) bipolar voltage and the extent of low-voltage zones (LVZ) according to gender as well as the results of a voltage-guided substrate ablation.

Methods

Consecutive patients who underwent a voltage-guided AF ablation were enrolled. LA endocardial voltage maps were obtained using a 3D electro-anatomical mapping system in sinus rhythm. LVZ was defined as <0.5 mV.

Results

A total of 115 patients were enrolled (74 men, 41 women). The LA bipolar voltage amplitude was twice lower in the whole LA (p < 0.01) and in each atrial region in women compared with men, whereas the LA indexed volume was similar. LVZ were found in 56.1% of women and 16.2% of men (p < 0.01). LVZ were also more extensive in women (p = 0.01), especially in the anterior LA. Atrial voltage alteration occurred earlier in women than in men. In a multivariate analysis, the female sex (OR 12.99; 95% CI, 3.23-51.63, p = 0.0001) and LA indexed volume (OR 1.09; 95% CI, 1.04-1.16, p = 0.001) were predictive of LVZ. Atrial arrhythmia-free survival was similar in men and women 36 months after a single ablation procedure.

Conclusion

The study reports a strong relationship between the female gender and atrial substrate remodeling. The female gender was significantly associated with higher incidence, earlier occurrence, and greater extent of LVZ compared with men. Despite the female-specific characteristics in atrial remodeling, LVZ-guided ablation may improve the AF ablation outcome in women.

Circumferential Pulmonary Vein Isolation With vs Without Additional Low-Voltage-Area Ablation in Older Patients With Paroxysmal Atrial Fibrillation: A Randomized Clinical Trial

Importance

The overall success rate of circumferential pulmonary vein isolation (CPVI) treatment in patients with paroxysmal atrial fibrillation (AF) remains suboptimal, especially in older patients.

Objective

To explore the incremental benefit of low-voltage-area ablation after CPVI in older patients with paroxysmal AF.

Design, Setting, and Participants

This randomized clinical trial was an investigator-initiated trial to compare the efficacy of additional low-voltage-area ablation beyond CPVI vs CPVI alone in older patients with paroxysmal AF. Participants were patients aged 65 to 80 years with paroxysmal AF who were referred for catheter ablation. They were enrolled in 14 tertiary hospitals in China from April 1, 2018, to August 3, 2020, and follow-up occurred through August 15, 2021.

Interventions

Patients were randomized (1:1) to undergo CPVI plus low-voltage-area ablation or CPVI alone. Low-voltage areas were defined as areas with amplitude less than 0.5 mV in more than 3 adjacent points. If low-voltage areas existed, additional substrate ablation was performed in the CPVI plus group but not the CPVI alone group.

Main Outcomes and Measures

The primary end point of the study was freedom from atrial tachyarrhythmia as documented by electrocardiogram during a clinical visit or lasting longer than 30 seconds during Holter recordings occurring after a single ablation procedure.

Results

Among 438 patients who were randomized (mean [SD] age, 70.5 [4.4] years; 219 men [50%]), 24 (5.5%) did not complete the blanking period and were not included for efficacy analysis. After a median follow-up of 23 months, the recurrence rate of atrial tachyarrhythmia was significantly lower in the CPVI plus group (31/209 patients, 15%) compared with the CPVI alone group (49/205, 24%; hazard ratio [HR], 0.61; 95% CI, 0.38-0.95; P = .03). In subgroup analyses, among all patients with low-voltage area, CPVI plus substrate modification was associated with a 51% decreased risk of ATA recurrence compared with CPVI alone (HR, 0.49; 95% CI, 0.25-0.94; P = .03).

Conclusions and Relevance

This study found that additional low-voltage-area ablation beyond CPVI decreased the ATA recurrence in older patients with paroxysmal AF compared with CPVI alone. Our findings merit further replication by larger trials with longer follow-up.

Trial Registration

ClinicalTrials.gov Identifier: NCT03462628.

Women Have More Recurrences of Atrial Fibrillation than Men after Thoracoscopic Ablation and Suffer More from Established Risk Factors

Introduction. Atrial fibrillation (AF) is more prevalent in men than in women. However, women with AF are more symptomatic, have a worse quality of life, a higher stroke risk and may therefore benefit most from ablation. In this study we aim to identify the risk of recurrent AF after thoracoscopic ablation, and assess the differential impact of the risk factors for recurrence between women and men. Method. This is a single center cohort study, including patients undergoing thoracoscopic ablation for advanced AF between 2008 and 2019. All patients were clinically followed up for two years with quarterly 24 h Holter monitoring and ECGs for the detection of recurrent AF. Left atrial appendage (LAA) tissue was collected for collagen analysis. Results. We included 571 patients, of whom 143 (25%) were women. Women were older than men (63 ± 8.3 y vs. 59 ± 8.5, p < 0.001), but had fewer cardiovascular risk factors, myocardial infarctions (1.4% vs. 6.5%, p = 0.03) and, in particular, vascular disease (7.0% vs. 16.1%, p = 0.01). Women suffered more from AF recurrence, driven by more atrial tachycardias, and sex was an independent risk factor for recurrence (HR1.41 [1.04–1.91], p = 0.028]). The presence of vascular disease was associated with an increased risk for AF recurrence in women, but not in men. In LAA histology, women had more collagen than men, as had patients with persistent compared to paroxysmal AF. Conclusion. Women had 15% more recurrences, driven by more atrial tachycardias, which may be explained by a more fibrotic atrial substrate. What’s new? Women undergoing thoracoscopic AF ablation have a higher risk of recurrent AF, driven by more atrial tachycardias. Among patients with left atrial enlargement or persistent AF, women have worse outcomes than men. Vascular disease was a risk factor for recurrence in women, but not in men. In a histopathologic analysis of the left atrial appendage, women had more collagen than men, as had patients with persistent compared to paroxysmal AF.

Sex Differences in Periprocedural and Long-Term Outcomes Following Transcatheter Left Atrial Appendage Occlusion: A Systematic Review and Meta-Analysis

BACKGROUND

Atrial fibrillation (AF) is among the most common arrhythmias associated with an increased risk of cardioembolic phenomena, including stroke. Percutaneous left atrial appendage occlusion (LAAO) has proven beneficial in reducing stroke and mortality in patients with atrial fibrillation who have contraindications to anticoagulation. However, the sex differences in outcomes following LAAO have not been studied systematically.

METHODS

Electronic databases PUBMED, Embase, and Web of Science were systematically searched until March 2022 for studies evaluating patient outcomes following LAAO for AF. The primary outcomes of interest were the risks of periprocedural stroke, major bleeding, pericardial complications, and all-cause mortality. Secondary outcomes included stroke risks, major bleeding, device-related thrombus, cardiovascular and all-cause mortality on long-term follow-up. A random-effects model meta-analysis was conducted, and heterogeneity was assessed using the I-squared test.

RESULTS

Sixteen studies were included in the final analysis encompassing 111,775 patients, out of which 45,441 (40.7 %) were women. Women had a significantly higher risk of peri-procedural complications including all-cause mortality [relative risk (RR), 95 % confidence intervals (CI); RR 1.94, 95 % CI 1.40-2.69], stroke [RR 1.85, 95 % CI 1.29-2.67], major bleeding [RR 1.63, 95 % CI 1.08-2.44], and pericardial events [RR 1.80, 95 % CI 1.58-2.05]. However, there were no statistically significant differences between sexes in terms of risk of stroke, major bleeding, device-related thrombus, cardiovascular and all-cause mortality on long-term follow-up.

CONCLUSION

Among patients undergoing LAAO implantation, women were at higher risk of periprocedural complications than men. This risk was not significant on long-term follow-up.

Catheter Ablation for Paroxysmal Atrial Fibrillation With Sick Sinus Syndrome: Insights From the Kansai Plus Atrial Fibrillation Registry

BACKGROUND

Coexisting sick sinus syndrome (SSS) is associated with both electrical and structural atrial remodelling in patients with atrial fibrillation (AF). Limited data are available concerning catheter ablation (CA) for AF in this condition. This study investigated the efficacy of CA as a curative therapy for AF and SSS in a large-scale prospective multicentre registry.

METHODS

The Kansai Plus Atrial Fibrillation (KPAF) registry enrolled 5,010 consecutive patients who underwent CA for AF; this included 3,133 patients with paroxysmal AF (mean age, 66 years; male, 69.3%; mean CHA₂DS₂-VASc score, 2.05±1.50; SSS, n=315 [tachy-brady syndrome, n=285]). The endpoints included the recurrence of AF with a blanking period of 90 days after CA, and de novo pacemaker implantation during the follow-up period (median duration, 2.93 years).

RESULTS

The AF-free survival did not significantly differ between patients with and those without SSS (n=2,818) after the initial (log-rank p=0.864) and final sessions (log-rank p=0.268). Pacemakers were implanted in 48 patients with SSS, and implantation in this group was significantly associated with AF recurrence, including early recurrence (adjusted odds ratio, 3.57; 95% confidence interval, 1.67-7.64; p=0.002). The remaining 85.3% of patients with SSS did not require pacemaker implantation at 3 years after CA.

CONCLUSIONS

Coexisting SSS did not adversely affect recurrence-free survival after CA for paroxysmal AF. Pacemaker implantation was not required in most patients with SSS, with AF recurrence serving as a strong predictor for this.

Sex Differences in the Combined Ablation and Left Atrial Appendage Closure: Results From LAACablation Registry

Background

More than 40% of left atrial appendage closure (LAAC) procedures were combined with atrial fibrillation (AF) ablation in China.

Objectives

This study aimed to assess the sex differences in the combined radiofrequency catheter ablation and LAAC procedures.

Methods

Data from the LAACablation (Left Atrial Appendage Closure in Combination With Catheter Ablation) registry, which enrolled AF patients who underwent the combined procedure between 2018 and 2021, were analyzed. Procedural complications, long-term outcomes, and quality of life (QoL) were compared between sexes.

Results

Of 931 patients, 402 (43.2%) were women. Compared with men, women were older (age 71.3 ± 7.4 years vs 68.7 ± 8.1 years; P < 0.001), presented more often with paroxysmal AF (52.5% vs 42.7%; P < 0.003), and had higher CHA₂DS₂-VASc scores (4.1 ± 1.5 vs 3.1 ± 1.5; P < 0.001), but received less often linear ablation and had shorter total procedural times and radiofrequency catheter ablation times. Women had similar rates of total and major procedural complications but presented with a higher incidence of minor complications than men (3.7% vs 1.3%; P = 0.027). Follow-up over 1,812 patient-years revealed similar adverse events between women and men, including all-cause death (HR: 0.89; 95% CI: 0.43-1.85; P = 0.754), thromboembolic events (HR: 1.17; 95% CI: 0.54-2.52; P = 0.697), major bleeding (HR: 0.96; 95% CI: 0.38-2.44; P = 0.935), and their composite (HR: 0.85; 95% CI: 0.56-1.28; P = 0.434). The recurrence rates of atrial tachyarrhythmia were also comparable between sexes presenting either paroxysmal or persistent AF. Women were seen with greater QoL impairment at baseline, but the sex gap narrowed at 1-year follow-up.

Conclusions

In AF patients who underwent the combined procedure, women had similar procedural safety and long-term efficacy to men and presented greater QoL improvement. (Left Atrial Appendage Closure in Combination With Catheter Ablation [LAACablation]; NCT03788941).

The occurrence of early atrial fibrillation after cardiac valve operation and the establishment of a nomogram model

Background

Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery, which is associated with age and massive bleeding. However, whether thyroid hormone (TH) level can affect POAF remains controversial.

Aim

To investigate the occurrence and risk factors of POAF, in particular, the preoperative TH level of patients was introduced into this study as a variable for analysis, and a column graph prediction model of POAF was constructed.

Methods

Patients who underwent valve surgery in Fujian Cardiac Medical Center from January 2019 to May 2022 were retrospectively analyzed and divided into POAF group and NO-POAF group. Baseline characteristics and relevant clinical data were collected from the two groups of patients. Independent risk factors for POAF were screened using univariate analysis and binary logistic regression analysis, and a column line graph prediction model was established based on the regression analysis results, and the diagnostic efficacy and calibration of the model were evaluated using the Receiver Operating Characteristic Curve (ROC) and calibration curve.

Results

A total of 2,340 patients underwent valve surgery, excluding 1,751 patients, a total of 589 patients were included, including 89 patients in POAF group and 500 patients in NO-POAF group. The total incidence of POAF was 15.1%. The results of the Logistics regression analysis showed that gender, age, leukocytes and TSH were risk factors of POAF. The area under the ROC curve of the nomogram prediction model for POAF was 0.747 (95% CI: 0.688-0.806, P < 0.001), with a sensitivity of 74.2% and specificity of 68%. Hosmer-Lemeshow test showed χ ²= 11.141, P = 0.194 > 0.05, the calibration curve was well fitted.

Conclusion

The results of this study show that gender, age, leukocyte and TSH are risk factors of POAF, and the nomogram prediction model has a good prediction effect. Due to the limited sample size and included population, more studies are needed to validate this result.

Sex Differences in the Regional Analysis of Nonpulmonary Vein Foci and Epicardial Adipose Tissue in Patients With Atrial Fibrillation

BACKGROUND

The mechanism underlying the sex differences in atrial fibrillation (AF) recurrence following pulmonary vein (PV) isolation is not fully understood. We hypothesized that non-PV foci and epicardial adipose tissue (EAT) play a key role.Methods and Results: Data from 304 consecutive patients (75% males) who underwent contrast-enhanced computed tomography and catheter ablation of AF were reviewed. The EAT around the atrium was measured separately in 4 parts of the atrium. All patients underwent high-dose isoproterenol infusions to assess the non-PV foci. Significantly more non-PV foci and less EAT around the atrium were observed in female patients than in male patients. In males, those with non-PV foci on the left atrial (LA) anterior wall had significantly greater EAT for the same lesions than those without non-PV foci. During a median follow-up of 27 months, the predictors of AF recurrence after first catheter ablation were female sex, presence of non-PV foci, LA diameter, and septal EAT index. A sex-specific analysis revealed that LA diameter was a predictor only in males and that the presence of non-PV foci in the septal region was a strong predictor in males (hazard ratio [HR]: 2.24) and females (HR: 3.65).

CONCLUSIONS

Sex-specific differences were observed in non-PV foci sites and local EAT and in regard to the predictors of AF recurrence.

Sex and racial disparities in catheter ablation

Sex and racial disparities in the presentation, diagnosis, and management of cardiac arrhythmias are recognized. Sex-specific differences in electrophysiological parameters are well known and are predominantly related to differences in ion channel expression and the influence of sex hormones. However, the relationship between hormonal or racial influence and arrhythmia mechanisms, presentation, and management needs to be better defined. Women and racial and ethnic groups are less likely to undergo catheter ablation procedures for treatment of cardiac arrhythmias. Underrepresentation of women and racial/ethnic groups in clinical trials has resulted in significant knowledge gaps. Whether sex and racial disparities in arrhythmia management reflect barriers in access to care, physician bias, patient values, and preferences or other factors requires further study.

Catheter ablation of symptomatic atrial fibrillation: Sex, ethnicity, and socioeconomic disparities

Catheter ablation for treatment of atrial fibrillation (AF), AF ablation, is more effective than antiarrhythmic drugs in reducing AF burden, reducing symptoms and increasing health-related quality of life. Although females more often experience AF-related symptoms, and have more severe symptoms, have lower quality of life, and experience more serious adverse effects of antiarrhythmic drugs than males, they are less likely to undergo AF ablation. Potential explanations for the disparity include older age at diagnosis, longer AF duration, a greater number of comorbidities, more extensive atrial fibrosis, and presumed lower success rate and more complications after AF ablation in women. Studies have failed to show sex-related differences in AF recurrence or serious complications following AF ablation but show more nuisance bleeds in women. Ethnic minorities, such as African Americans and Latin Americans, and individuals of low socioeconomic status are also less likely to undergo AF ablation, possibly associated with greater numbers of comorbidities, lack of patient advocacy, healthcare costs, and inadequate insurance coverage. Inclusion of marginalized patient groups in clinical trials of AF treatment and a personalized, patient-centered approach may expand equality in utilization of AF ablation.

Sex differences involved in persistent atrial fibrillation recurrence after radiofrequency ablation

BACKGROUND

In recent years, the difference in outcomes of radiofrequency catheter ablation (RFCA) in persistent atrial fibrillation patients has risen. In particular, biological sex seems involved in a different response to the AF ablation procedure. In our study, we analyzed the AF recurrences after RFCA assessing the other association between male/female patients with the outcomes.

METHODS

We enrolled 106 patients (74.5% men) with persistent atrial fibrillation with scheduled follow-up. The baseline clinical characteristics and AF recurrence after RFCA were compared between men and women. Cox regression analyses were performed to determine the risk predictors of AF recurrence.

RESULTS

The proportion of RFCA in women was lower than that in men. Men with persistent AF were younger than women (58.6 ± 10.4 years vs. 65.1 ± 8.7 years, respectively; p = 0.003). The left atrium (LA) diameter was higher in males (43.7 ± 4.6 mm vs. 41.3 ± 5.5 mm; p = 0.028), and the level of left heart ejection fraction (LVEF) was higher in females (59.4 ± 6.9% vs. 64.1 ± 5.5%; p = 0.001). Sex differences in AF recurrence after RFCA were significant during the median 24.4-month (interquartile range: 15.2-30.6 months) follow-up period, and the recurrence rate of AF in women was significantly higher than that in men (p = 0.005). Univariable Cox regression analysis showed that female sex was a risk factor for persistent AF recurrence after RFCA [HR: 2.099 (1.087-4.053)]. Univariate Cox regression analysis revealed that non-PV ablation not associated with AF recurrence [HR: 1.003 (0.516-1.947)].

CONCLUSION

In a monocentric cohort of persistent AF patients, the female biological sex was associated with a higher risk of AF recurrence after RFCA.

The influence of sex on early post-operative atrial fibrillation after cardiac surgery

BACKGROUND

Early post-operative atrial fibrillation (EPOAF) occurs more frequently in male (M) patients. However, most patients included in EPOAF studies were also M. The aim of the present study was to compare, in a matched M and F population, the occurrence of EPOAF episodes and EPOAF characteristics using continuous rhythm monitoring (CRM) during the first five post-operative days.

METHODS

Our study population consisted of 30 F patients matched with 30 M patients admitted for elective cardiac surgery. After cardiac surgery, patients were continuously monitored for a maximum of 5 days, and the burden of EPOAF episodes was quantified.

RESULTS

No significant differences in the onset, number, burden, total duration, shortest, median and longest EPOAF episode were detected between M and F patients. However, EPOAF occurred more frequently on the third post-operative day (F: 16 vs. M: 7; p = .013).

CONCLUSIONS

Except for the occurrence of the EPOAF on the third post-operative day. EPOAF characteristics did not differ between M and F patients.

The Complex Relation between Atrial Cardiomyopathy and Thrombogenesis

Heart disease, as well as systemic metabolic alterations, can leave a ‘fingerprint’ of structural and functional changes in the atrial myocardium, leading to the onset of atrial cardiomyopathy. As demonstrated in various animal models, some of these changes, such as fibrosis, cardiomyocyte hypertrophy and fatty infiltration, can increase vulnerability to atrial fibrillation (AF), the most relevant manifestation of atrial cardiomyopathy in clinical practice. Atrial cardiomyopathy accompanying AF is associated with thromboembolic events, such as stroke. The interaction between AF and stroke appears to be far more complicated than initially believed. AF and stroke share many risk factors whose underlying pathological processes can reinforce the development and progression of both cardiovascular conditions. In this review, we summarize the main mechanisms by which atrial cardiomyopathy, preceding AF, supports thrombogenic events within the atrial cavity and myocardial interstitial space. Moreover, we report the pleiotropic effects of activated coagulation factors on atrial remodeling, which may aggravate atrial cardiomyopathy. Finally, we address the complex association between AF and stroke, which can be explained by a multidirectional causal relation between atrial cardiomyopathy and hypercoagulability.

Do Elderly Patients with Atrial Fibrillation Have Comparable Ablation Outcomes Compared to Younger Ones? Evidence from Pooled Clinical Studies

Background: Age is an independent risk factor of the progress and prognosis of atrial fibrillation (AF). However, ablation outcomes between elderly and younger patients with AF remain elusive. Methods: Cochrane Library, Embase, PubMed, and Web of Science were systematically searched up to 1 April 2022. Studies comparing AF ablation outcomes between elderly and younger patients and comprising outcomes of AF ablation for elderly patients were included. Trial sequential analysis (TSA) was performed to adjust for random error and lower statistical power in our meta-analysis. Subgroup analysis identified possible determinants of outcome impact for elderly patients after ablation. Moreover, linear and quadratic prediction fit plots with confidence intervals were performed, as appropriate. Results: A total of 27 studies with 113,106 AF patients were eligible. Compared with the younger group, the elderly group was significantly associated with a lower rate of freedom from AF (risk ratio [RR], 0.95; p = 0.008), as well as a higher incidence of safety outcomes (cerebrovascular events: RR, 1.64; p = 0.000; serious hemorrhage complications: RR, 1.50; p = 0.035; all-cause death: RR, 2.61; p = 0.003). Subgroup analysis and quadratic prediction fit analysis revealed the follow-up time was the potential determinant of freedom from AF for elderly patients after AF ablation. Conclusions: Our meta-analysis suggests that elderly patients may have inferior efficacy and safety outcomes to younger patients with AF ablation. Moreover, the follow-up time may be a potential determinant of outcome impact on freedom from AF for elderly patients after AF ablation.

Sex Differences in Epicardial Adipose Tissue: Association With Atrial Fibrillation Ablation Outcomes

Background

There are significant differences in the prevalence and prognosis of atrial fibrillation (AF) between sexes. Epicardial adipose tissue (EAT) has been found as a risk factor for AF. This study aimed to evaluate whether sex-based EAT differences were correlated with AF recurrence and major adverse cardiovascular events (MACE).

Methods

In this study, postmenopausal women and age, BMI, and type of AF matched men who had received first catheter ablation were included. EAT volume was quantified based on the pre-ablation cardiac computed tomography (CT) images. Clinical, CT, and echocardiographic variables were compared by sex groups. The predictors of AF recurrence and MACE were determined through Cox proportional hazards regression.

Results

Women were found with significantly lower total EAT volumes (P < 0.001) but higher periatrial/total (P/T) EAT ratios (P = 0.009). The median follow-up duration was 444.5 days. As revealed by the result of the Kaplan-Meier survival analysis, the women were found to have a significantly higher prevalence of AF recurrence (log rank, P = 0.011) but comparable MACE (log rank, P = 0.507) than men. Multivariate analysis demonstrated that female gender (HR: 1.88 [95% CI: 1.03, 4.15], P = 0.032), persistent AF (HR: 2.46 [95% CI: 1.19, 5.05], P = 0.015), left atrial (LA) dimension (HR: 1.47 [95% CI: 1.02, 2.13], P = 0.041), and P/T EAT ratio (HR: 1.73 [95% CI: 1.12, 2.67], P = 0.013) were found as the independent predictors of AF recurrence. Sex-based subgroup multivariable analysis showed that the P/T EAT ratio was an independent predictor of AF recurrence in both men (HR: 1.13 [95% CI: 1.01, 1.46], P = 0.047) and women (HR: 1.37 [95% CI: 1.11, 1.67], P = 0.028). While age (HR: 1.81 [95% CI: 1.18, 2.77], P = 0.007), BMI (HR: 1.44 [95% CI: 1.02, 2.03], P = 0.038), and periatrial EAT volume (HR: 1.31 [95% CI: 1.01, 1.91], P = 0.046) were found to be independent of MACE.

Conclusion

Women had a higher P/T EAT ratio and AF post-ablation recurrence but similar MACE as compared with men. Female gender and P/T EAT ratio were found to be independent predictors of AF recurrence, whereas age and periatrial EAT volume were found to be independent predictors of MACE.