The Relationship Between Cardiac CT-based Left Atrial Structure and Epicardial Adipose Tissue and Postablation Atrial Fibrillation Recurrence Within 2 Years

PURPOSE

The aim of this study was to explore the association of cardiac CT-based left atrium (LA) structural and functional parameters and left atrial epicardial adipose tissue (LA-EAT) parameters with postablation atrial fibrillation (AF) recurrence within 2 years.

MATERIALS AND METHODS

Contrast-enhanced cardiac CT images of 286 consecutive AF patients (median age: 65 y; 97 females) who underwent initial ablation between June 2018 and June 2020 were retrospectively analyzed. Structural and functional parameters of LA, including maximum and minimum volume and ejection fraction of LA and left atrial appendage (LAA), and LA-EAT volume, were measured. The body surface area indexed maximum and minimum volume of LA (LAVI max , LAVI min ) and LAA (LAAVI max , LAAVI min ), and LA-EAT volume index (LA-EATVI) were calculated. Independent predictors of AF recurrence were determined using Cox regression analysis. The clinical predictors were added to the imaging predictors to build a combined model (clinical+imaging). The predictive performance of the clinical, imaging, and combined models was assessed using the area under the receiver operating characteristics curve (AUC).

RESULTS

A total of 108 (37.8%) patients recurred AF within 2 years after ablation at a median follow-up of 24 months (IQR=11, 32). LA and LAA size and LA-EAT volume were significantly increased in patients with AF recurrence ( P <0.05). After the multivariable regression analysis, LA-EATVI, LAAVI max , female sex, AF duration, and stroke history were independent predictors for AF recurrence. The combined model exhibited superior predictive performance compare to the clinical model (AUC=0.712 vs. 0.641, P =0.023) and the imaging model (AUC=0.712 vs. 0.663, P =0.018).

CONCLUSION

Cardiac CT-based LA-EATVI and LAAVI max are independent predictors for postablation AF recurrence within 2 years and may provide a complementary value for AF recurrence risk assessment.

Sex- and age-specific differences in the use of antiarrhythmic therapies among atrial fibrillation patients: a nationwide cohort study

AIMS

Atrial fibrillation (AF) patients frequently require active rhythm control therapy to maintain sinus rhythm and reduce symptom burden. Our study assessed whether antiarrhythmic therapies (AATs) are used disproportionately between men and women after new-onset AF.

METHODS AND RESULTS

The nationwide Finnish anticoagulation in AF registry-based linkage study covers all patients with new-onset AF in Finland during 2007-2018. Study outcomes included initiation of AATs in the form of antiarrhythmic drugs (AADs), cardioversion, or catheter ablation. The study population constituted of 229 565 patients (50% females). Women were older than men (76.6 ± 11.8 vs. 68.9 ± 13.4 years) and had higher prevalence of hypertension or hyperthyroidism, but lower prevalence of vascular disease, diabetes, renal disease, and cardiomyopathies than men. Overall, 17.6% of women and 25.1% of men were treated with any AAT. Women were treated with AADs more often than men in all age groups [adjusted subdistribution hazard ratio (aSHR) 1.223, 95% confidence interval (CI) 1.187-1.261]. Cardioversions were also performed less often on women than on men aged <65 years (aSHR 0.722, 95% CI 0.695-0.749), more often in patients ≥ 75 years (aSHR 1.166, 95% CI 1.108-1.227), while no difference between the sexes existed in patients aged 65-74 years. Ablations were performed less often in women aged <65 years (aSHR 0.908, 95% CI 0.826-0.998) and ≥75 years (aSHR 0.521, 95% CI 0.354-0.766), whereas there was no difference in patients aged 65-74 years.

CONCLUSION

Women used more AAD than men in all age groups but underwent fewer cardioversion and ablation procedures when aged <65 years.

Male and female atria exhibit distinct acute electrophysiological responses to sex steroids

The electrophysiological properties of the hearts of women and men are different. These differences are at least partly mediated by the actions of circulating estrogens and androgens on the cardiomyocytes. Experimentally, much of our understanding in this field is based on studies focusing on ventricular tissue, with considerably less known in the context of atrial electrophysiology. The aim of this investigation was to compare the electrophysiological properties of male and female atria and assess responses to acute sex steroid exposure. Age-matched adult male and female C57BL/6 mice were anesthetized (4 % isoflurane) and left atria isolated. Atria were loaded with Di-4-ANEPPS voltage sensitive dye and optical mapping performed to assess action potential duration (APD; at 10 %, 20 %, 30 %, 50 %, and 70 % repolarization) and conduction velocity in the presence of 1 nM and 100 nM 17β-estradiol or testosterone. Male and female left atria demonstrated similar baseline action potential duration and conduction velocity, with significantly greater APD70 spatial heterogeneity evident in females. 17β-estradiol prolonged action potential duration in both sexes - an effect that was augmented in females. Atrial conduction was slowed in the presence of 100 nM 17β-estradiol in both males and females. Testosterone prolonged action potential duration in males only and did not modulate conduction velocity in either sex. This study provides novel insights into male and female atrial electrophysiology and its regulation by sex steroids. As systemic sex steroid levels change and intra-cardiac estrogen synthesis capacity increases with aging, these actions may have an increasingly important role in determining atrial arrhythmia vulnerability.

Participation of women in clinical studies of atrial fibrillation in the Northern Netherlands

INTRODUCTION

Concerns exist of women underrepresentation in atrial fibrillation (AF) studies, potentially limiting the generalisability of study findings to women with AF. We assessed the participation of women in AF clinical studies performed at a tertiary care centre in the Northern Netherlands.

METHODS

Eight AF clinical studies with screening logs were available for analysis. To identify sex-specific differences, patient inclusion and exclusion and reasons for exclusion were assessed. Participation-to-prevalence ratios (PPRs) were calculated to evaluate the representation of women in the studies relative to the AF sex distribution of the general population in the Netherlands (2019 Global Burden of Disease study).

RESULTS

We included 1739 screened patients with AF in the analysis, of whom 722 (41.5%) were women. Of the patients screened, 161 (9%) were enrolled. Median age of screened patients was 69 years (interquartile range (IQR): 61-77), and women were older than men (71 years; IQR: 63-79 vs 68 years; IQR: 60-75; p < 0.001). Women were not underscreened compared with men (PPR: 1.09; 95% confidence interval (CI): 1.08-1.10), disproportionally excluded (92% vs 90%; p = 0.10) or less willing to participate (17% vs 15%; p = 0.36). Women had an overall PPR of 1.05 (95% CI: 1.05-1.06) compared with the general AF population.

CONCLUSION

At our tertiary hospital in the Northern Netherlands, women appeared to be well-represented in AF studies. The current study advocates for the adoption of a more comprehensive measure of equity, such as the PPR, and screening log evaluation to improve the generalisability of study findings to the entire clinical AF population.

Sex-specific association of cardiovascular drug doses with adverse outcomes in atrial fibrillation

OBJECTIVES

Sex differences occur in atrial fibrillation (AF), including age at first manifestation, pathophysiology, treatment allocation, complication rates and quality of life. However, optimal doses of cardiovascular pharmacotherapy used in women with AF with or without heart failure (HF) are unclear. We investigated sex-specific associations of beta-blocker and renin-angiotensin system (RAS) inhibitor doses with cardiovascular outcomes in patients with AF or AF with concomitant HF.

METHODS

We used data from the prospective Basel Atrial Fibrillation and Swiss Atrial Fibrillation cohorts on patients with AF. The outcome was major adverse cardiovascular events (MACEs), including death, myocardial infarction, stroke, systemic embolisation and HF-related hospitalisation. Predictors of interest were spline (primary analysis) or quartiles (secondary analysis) of beta-blocker or RAS inhibitor dose in per cent of the maximum dose (reference), in interaction with sex. Cox models were adjusted for demographics, comorbidities and comedication.

RESULTS

Among 3961 patients (28% women), MACEs occurred in 1113 (28%) patients over a 5-year median follow-up. Distributions of RAS inhibitor and beta-blocker doses were similar in women and men. Cox models revealed no association between beta-blocker dose or RAS inhibitor dose and MACE. In a subgroup of patients with AF and HF, the lowest hazard of MACE was observed in women prescribed 100% of the RAS inhibitor dose. However, there was no association between RAS dose quartiles and MACE.

CONCLUSIONS

In this study of patients with AF, doses of beta-blockers and RAS inhibitors did not differ by sex and were not associated with MACE overall.

Adequacy of Dialysis and Incidence of Atrial Fibrillation in Patients Undergoing Hemodialysis

BACKGROUND

Atrial fibrillation (AF) can lead to stroke, heart failure, and mortality and has a greater prevalence in dialysis patients than in the general population. Several studies have suggested that uremic toxins may contribute to the development of AF. However, the association between dialysis adequacy and incident AF has not been well established.

METHODS

In this retrospective nationwide cohort study, we analyzed data from the Korean National Periodic Hemodialysis Quality Assessment from 2013 to 2015 of patients who received outpatient maintenance hemodialysis 3× a week. The main exposure was single pooled Kt/V (spKt/V), which is the dialysis adequacy index, and the primary outcome was the development of AF. For the primary analysis, patients were categorized into quartiles according to baseline spKt/V. The lowest quartile, representing the lowest adequacy, was used as the reference group. Fine-Gray subdistribution hazard models were used, treating all-cause mortality as a competing risk.

RESULTS

Of 25 173 patients, the mean age was 60 (51-69) years, and 14 772 (58.7%) were men. During a median follow-up of 5.7 years, incident AF occurred in a total of 3883 (15.4%) patients. Participants with a higher spKt/V tended to have lower AF incidence. In survival analysis, a graded association was observed between the risk of incident AF and spKt/V quartiles: subdistribution hazard ratios and 95% CIs for the second, third, and the highest quartile compared with the lowest quartile were 0.90 (95% CI, 0.82-0.98), 0.84 (95% CI, 0.77-0.93), and 0.79 (95% CI, 0.72-0.88), respectively.

CONCLUSIONS

This nationwide cohort study showed that a higher spKt/V is associated with a reduced risk of incident AF. These findings suggests that reducing uremic toxin burden through enhanced dialysis clearance may be associated with a lower risk of AF development in patients undergoing maintenance hemodialysis.

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.

Symptoms of gastroesophageal reflux disease predicts low voltage zones in the posteroinferior left atrium in patients with persistent atrial fibrillation

Background

The presence of low voltage zones (LVZs) in the left atrium (LA) is associated with the recurrence of atrial fibrillation (AF) after pulmonary vein isolation. Numerous studies have posited a link between gastroesophageal reflux disease (GERD) and AF, attributing this relationship to the anatomical proximity of the esophagus to the posteroinferior wall of the LA.

Objective

The objective of this study was to investigate whether GERD can predict the presence of LVZs in the posteroinferior wall of the LA.

Methods

Five hundred fifty-one patients with persistent AF, scheduled for their first AF ablation procedure, were prospectively enrolled. Voltage maps were collected using a multipolar catheter, and LVZs were defined as areas measuring ≥3 cm2 with a peak-to-peak bipolar voltage of <0.5 mV. Information on GERD symptoms was collected from the participants through a self-administered questionnaire.

Results

Long-standing persistent AF was present in 22.3% of the total cohort. GERD was present in 29% of patients and LVZs in the posteroinferior wall in 12.7%. In the multivariable analysis, patients with GERD were found to have more than twice the odds (odds ratio 2.26; 95% confidence interval 1.24-4.13; P = .008) of exhibiting LVZs in the posteroinferior wall of the LA than patients without GERD. GERD was not associated with LVZs in any other region of the LA.

Conclusion

GERD was found to be independently associated with LVZs in the posteroinferior LA. This association may be attributable to inflammation and may partly explain the link between GERD and 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 Differences in the Expression of Cardiac Remodeling and Inflammatory Cytokines in Patients with Obstructive Sleep Apnea and Atrial Fibrillation

Although there is a link between obstructive sleep apnea (OSA) and atrial fibrillation (AF) and numerous investigations have examined the mechanism of AF development in OSA patients, which includes cardiac remodeling, inflammation, and gap junction-related conduction disorder, there is limited information regarding the differences between the sexes. This study analyzes the impact of sex differences on the expression of cardiac remodeling, inflammatory cytokines, and gap junctions in patients with OSA and AF. A total of 154 individuals diagnosed with sleep-related breathing disorders (SRBDs) were enrolled in the study and underwent polysomnography and echocardiography. Significant OSA was defined as an apnea-hypopnea index (AHI) of ≥15 per hour. Exosomes were purified from the plasma of all SRBD patients and incubated in HL-1 cells to investigate their effects on inflammatory cytokines and GJA1 expression. The differences in cardiac remodeling and expression of these biomarkers in both sexes were analyzed. Of the 154 enrolled patients, 110 patients were male and 44 patients were female. The LA sizes and E/e' ratios of male OSA patients with concomitant AF were greater than those of control participants and those without AF (all p < 0.05). Meanwhile, female OSA patients with AF had a lower left ventricular ejection fraction than those OSA patients without AF and control subjects (p < 0.05). Regarding the expression of inflammatory cytokines and GJA1, the mRNA expression levels of GJA1 were lower and those of IL-1β were higher in those male OSA patients with AF than in those male OSA patients without AF and control subjects (p < 0.05). By contrast, mRNA expression levels of HIF-1α were higher in those female OSA patients with and without AF than in control subjects (p < 0.05). In conclusion, our study revealed sex-specific differences in the risk factors and biomarkers associated with AF development in patients with OSA.

Influence of sex on efficacy of exercise training for patients with symptomatic atrial fibrillation: insights from the ACTIVE-AF randomized controlled trial

AIMS

Exercise training reduces recurrence of arrhythmia and symptom severity amongst patients with symptomatic, non-permanent atrial fibrillation (AF). However, there is little evidence on whether this effect is modified by patient sex. In a sub-analysis from the ACTIVE-AF (A Lifestyle-based, PhysiCal AcTIVity IntErvention for Patients With Symptomatic Atrial Fibrillation) randomized controlled trial, we compared the effects of exercise training on AF recurrence and symptom severity between men and women.

METHODS AND RESULTS

The ACTIVE-AF study randomized 120 patients (69 men, 51 women) with paroxysmal or persistent AF to receive an exercise intervention combining supervised and home-based aerobic exercise over 6 months or to continue standard medical care. Patients were followed over a 12-month period. The co-primary outcomes were recurrence of AF, off anti-arrhythmic medications and without catheter ablation, and AF symptom severity scores. By 12 months, recurrence of AF was observed in 50 (73%) men and 34 (67%) women. In an intention-to-treat analysis, there was a between-group difference in favour of the exercise group for both men [hazard ratio (HR) 0.52, 95% confidence interval (CI): 0.29-0.91, P = 0.022] and women (HR 0.47, 95% CI: 0.23-0.95, P = 0.035). At 12 months, symptom severity scores were lower in the exercise group compared with controls amongst women but not for men.

CONCLUSION

An exercise-based intervention reduced arrhythmia recurrence for both men and women with symptomatic AF. Symptom severity was reduced with exercise in women at 12 months. No difference was observed in symptom severity for men.

REGISTRATION

Australia and New Zealand Clinical Trials Registry: ACTRN12615000734561.

Gender-Based Clinical, Therapeutic Strategies and Prognosis Differences in Atrial Fibrillation

BACKGROUND

There are limited data on gender-based differences in atrial fibrillation (AF) treatment and prognosis. We aimed to examine gender-related differences in medical attention in an emergency department (ED) and follow-up (FU) among patients diagnosed with an AF episode and to determine whether there are gender-related differences in clinical characteristics, therapeutic strategies, and long-term adverse events in this population.

METHODS

We performed a retrospective observational study of patients who presented to a tertiary hospital ER for AF from 2010 to 2015, with a minimum FU of one year. Data on medical attention received, mortality, and other adverse outcomes were collected and analyzed.

RESULTS

Among the 2013 patients selected, 1232 (60%) were female. Women were less likely than men to be evaluated by a cardiologist during the ED visit (11.5% vs. 16.6%, p = 0.001) and were less likely to be admitted (5.9% vs. 9.5%, p < 0.05). Electrical cardioversion was performed more frequently in men, both during the first episode (3.4% vs. 1.2%, p = 0.001) and during FU (15.9% vs. 10.6%, p < 0.001), despite a lower AF recurrence rate in women (9.9% vs. 18.1%). During FU, women had more hospitalizations for heart failure (26.2% vs. 16.1%, p < 0.001).

CONCLUSIONS

In patients with AF, although there were no gender differences in mortality, there were significant differences in clinical outcomes, medical attention received, and therapeutic strategies. Women underwent fewer attempts at cardioversion, had a lower probability of being evaluated by cardiologists, and showed a higher probability of hospitalization for heart failure. Being alert to these inequities should facilitate the adoption of measures to correct them.

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.

Sex Differences in Atrial Fibrillation and Associated Complications in Hypertensive Patients with Left Ventricular Hypertrophy: The LIFE Study

BACKGROUND

There is no consensus on whether biological differences account for the higher risk of stroke seen in females compared to males with atrial fibrillation (AF).

METHODS

Capitalizing on The Losartan Intervention for Endpoint study, a multicenter randomized clinical trial randomizing 9,193 patients and followed for at least four years, we aimed to identify sex differences in the risk of stroke in the presence of AF in patients with hypertension and left ventricular hypertrophy (LVH).

RESULTS

342 Patients had a history of AF, and 669 developed new-onset AF. History of AF and new-onset AF were more prevalent among males (5.0% vs. 2.9% and 3.0% vs. 0.9%) in patients aged 55-63 years, but the relative difference decreased with age. Females with new-onset AF tended to have a higher risk of stroke than males (HR 1.52 [95% CI 0.95-2.43]). However, females with a history of AF did not have a higher risk than males (HR 0.88 [95% CI 0.5-1.6]). In patients with new-onset AF, the relative higher stroke risk in females increased with age. Among patients with a history of AF, stroke risk was comparable and increased with age in both sexes.

CONCLUSIONS

Among patients with hypertension and LVH, females with new-onset AF had a higher risk of stroke than males, especially in patients above 64 years. However, the risk did not differ between the sexes among patients with a history of AF.

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.

The inter-chamber differences in the contractile function between left and right atrial cardiomyocytes in atrial fibrillation in rats

Introduction

The left and right atria (LA, RA) work under different mechanical and metabolic environments that may cause an intrinsic inter-chamber diversity in structure and functional properties between atrial cardiomyocytes (CM) in norm and provoke their different responsiveness to pathological conditions. In this study, we assessed a LA vs. RA difference in CM contractility in paroxysmal atrial fibrillation (AF) and underlying mechanisms.

Methods

We investigated the contractile function of single isolated CM from LA and RA using a 7-day acetylcholine (ACh)-CaCl2 AF model in rats. We compared auxotonic force, sarcomere length dynamics, cytosolic calcium ([Ca2+]i) transients, intracellular ROS and NO production in LA and RA CM, and analyzed the phosphorylation levels of contractile proteins and actin-myosin interaction using an in vitro motility assay.

Results

AF resulted in more prominent structural and functional changes in LA myocardium, reducing sarcomere shortening amplitude, and velocity of sarcomere relengthening in mechanically non-loaded LA CM, which was associated with the increased ROS production, decreased NO production, reduced myofibrillar content, and decreased phosphorylation of cardiac myosin binding protein C and troponin I. However, in mechanically loaded CM, AF depressed the auxotonic force amplitude and kinetics in RA CM, while force characteristics were preserved in LA CM.

Discussion

Thus, inter-atrial differences are increased in paroxysmal AF and affected by the mechanical load that may contribute to the maintenance and progression of AF.

Arrhythmia mechanism dependent pulmonary vein ablation in paroxysmal atrial fibrillation

Atrial fibrillation (AF) often requires invasive treatment by ablation to decrease symptom burden. The pulmonary veins (PV) are thought to trigger paroxysms of AF, and ablative PV isolation (PVI) is a cornerstone in AF treatment. However, incomplete PVI, where electrical conduction between the PV and left atrium (LA) is maintained, is curative of AF in a subset of patients. This implies that an antiarrhythmic effect other than electrical isolation between the PV and LA plays a role in AF prevention in these patients. We reason that the PV myocardium constitutes an arrhythmogenic substrate conducive to reentry in the patients with curative incomplete PVI. This PV substrate is amenable to ablation, even when conduction between the LA and PV persists. We propose that PV ablation strategies are differentiated to fit the arrhythmogenic mechanisms in the individual patient. PV substrate modification in patients with PV reentry may constitute a new therapeutic approach that is potentially simpler and more effective, in this subgroup of patients.

Development and Validation of a Novel Prognostic Tool to Predict Recurrence of Paroxysmal Atrial Fibrillation after the First-Time Catheter Ablation: A Retrospective Cohort Study

There is no gold standard to tell frustrating outcomes after the catheter ablation of paroxysmal atrial fibrillation (PAF). The study aims to construct a prognostic tool. We retrospectively analyzed 315 patients with PAF who underwent first-time ablation at the Second Xiangya Hospital of Central South University. The endpoint was identified as any documented relapse of atrial tachyarrhythmia lasting longer than 30 s after the three-month blanking period. Univariate Cox regression analyzed eleven preablation parameters, followed by two supervised machine learning algorithms and stepwise regression to construct a nomogram internally validated. Five factors related to ablation failure were as follows: female sex, left atrial appendage emptying flow velocity ≤31 cm/s, estimated glomerular filtration rate <65.8 mL/(min·1.73 m²), P wave duration in lead aVF ≥ 120 ms, and that in lead V1 ≥ 100 ms, which constructed a nomogram. It was correlated with the CHA₂DS₂-VASc score but outperformed the latter evidently in discrimination and clinical utility, not to mention its robust performances in goodness-of-fit and calibration. In addition, the nomogram-based risk stratification could effectively separate ablation outcomes. Patients at risk of relapse after PAF ablation can be recognized at baseline using the proposed five-factor nomogram.

Sex Differences in the Association Between Hypertension and Incident Atrial Fibrillation

Background Limited evidence is available on sex differences about the association between hypertension and incident atrial fibrillation (AF). Methods and Results We used a nationwide health checkup and claims database to analyze 3 383 738 adults (median age, 43 (36-51) years, 57.4% men). We investigated the relationship between hypertension and incident AF in men and women using a Cox regression model. We used restricted cubic spline functions to identify the association of blood pressure (BP) as a continuous parameter with incident AF. We categorized the men and women into 4 groups according to the 2017 American College of Cardiology/American Heart Association BP guidelines. During a mean follow-up of 1199±950 days, 13 263 AF diagnoses were recorded. The incidence (95% CI) of AF was 15.8 (15.5-16.1) per 10 000 person-years in men and 6.1 (5.9-6.3) per 10 000 person-years in women. Compared with normal BP, elevated BP, stage 1 hypertension, and stage 2 hypertension were associated with an increased risk AF in both men and women. However, the hazard ratios were greater in women than in men, and the P value for interactions in the multivariable model was 0.0076. The models using restricted cubic spline showed that the risk of AF associated with elevated systolic BP increased steeply above an approximate threshold of systolic BP of 130 mm Hg in men and 100 mm Hg in women. Although our primary findings were consistent across subgroup analyses, this association was most significant in younger individuals. Conclusions Although the incidence of AF was higher in men, the association between hypertension and incident AF was more pronounced in women than in men, suggesting a potential sex difference in the relationship between hypertension and incident AF.

Prevalence of Postoperative Atrial Fibrillation and Impact to Nursing Practice—A Cross Sectional Study

Background: Atrial fibrillation is the most common clinically significant cardiac arrhythmia, and it might lead to heart failure, which prolongs the duration of hospitalization and consequently increases the cost of treatment. Thus, diagnosing and treating atrial fibrillation should be the first line of defense against further complications. This study aimed to determine the incidence rate of postoperative atrial fibrillation and correlation with cardiac surgery on heart valves. A specific aim was to determine the relationship between the prevalence of atrial fibrillation and socio-demographic features. Methods: The study has a prospective cross-sectional design. The questionnaire was anonymous, requesting socio-demographic information as inclusion criteria, and the data were analyzed using descriptive statistics methods. Results: The sample was 201 patients. χ2 test and t-test were performed where we found that the frequency of atrial fibrillation was higher in the groups that have had valve surgery compared to other cardiac surgeries (χ2 = 7.695, ss = 2, p = 0.021). Atrial fibrillation increased with the age of the patients, but the prevalence of atrial fibrillation was not correlated with body weight. Conclusion: The results of this this study show that atrial fibrillation was higher in the participants who had valve surgery compared to other cardiac surgeries. There was also an increase in atrial fibrillation in the older participants. The results of this study can help to improve nursing practice and the quality of care for cardiac surgery patients with regard to daily activities, or planning nursing care due to the patient’s condition.

Efficacy of mobile health-technology integrated care based on the 'Atrial fibrillation Better Care' (ABC) pathway in relation to sex: a report from the mAFA-II randomized clinical trial

The Mobile Health Technology for Improved Screening and Optimized Integrated Care in AF (mAFA-II) cluster-randomized trial showed that a mobile health (mHealth)-implemented 'Atrial fibrillation Better Care' (ABC) pathway approach reduced the risk of adverse events in atrial fibrillation (AF) patients. Whether this benefit can be applied to both males and females is unclear, especially given the suboptimal management and poorer cardiovascular outcomes in females with AF. In this post-hoc analysis, we performed a sex-stratified analysis of the mAFA-II trial. Between June 2018 and August 2019, adult AF patients were enrolled across 40 centers in China. The primary outcome was the composite of stroke, thromboembolism, all-cause death, and re-hospitalization. The effect of mAFA intervention according to sex was evaluated through adjusted Cox-regression models. Among the 3,324 patients enrolled in the trial, 2,062 (62.0%) patients were males (mean age: 67.5 ± 14.3 years; 1,021 allocated to mAFA intervention) and 1,262 (38.0%) were females (mean age: 70.2 ± 13.0; 625 allocated to mAFA intervention). A significant risk reduction of the primary composite outcome in patients allocated to mAFA intervention was observed in both males (adjusted hazard ratio [aHR] and 95% confidence interval [CI] 0.30 [0.17-0.52]) and females (aHR [95%CI] 0.50 [0.27-0.92]), without statistically significant interaction (p = 0.225). Sex-based interactions were observed for other secondary outcomes, including all-cause death (p = 0.026) and bleeding events (p = 0.032). A mHealth-technology implemented ABC pathway was similarly effective in reducing the risk of adverse clinical events both in male and female patients. Secondary outcomes showed greater benefits of mAFA intervention in men.

Resting membrane potential is less negative in trabeculae from right atrial appendages of women, but action potential duration does not shorten with age

AIMS

The incidence of atrial fibrillation (AF) increases with age. Women have a lower risk. Little is known on the impact of age, sex and clinical variables on action potentials (AP) recorded in right atrial tissue obtained during open heart surgery from patients in sinus rhythm (SR) and in longstanding AF. We here investigated whether age or sex have an impact on the shape of AP recorded in vitro from right atrial tissue.

METHODS

We performed multivariable analysis of individual AP data from trabeculae obtained during heart surgery of patients in SR (n = 320) or in longstanding AF (n = 201). AP were recorded by sharp microelectrodes at 37 °C at 1 Hz. Impact of clinical variables were modeled using a multivariable mixed model regression.

RESULTS

In SR, AP duration at 90% repolarization (APD₉₀) increased with age. Lower ejection fraction and higher body mass index were associated with smaller action potential amplitude (APA) and maximum upstroke velocity (V_max). The use of beta-blockers was associated with larger APD₉₀. In tissues from women, resting membrane potential was less negative and APA as well as V_max were smaller. Besides shorter APD₂₀ in elderly patients, effects of age and sex on atrial AP were lost in AF.

CONCLUSION

The higher probability to develop AF at advanced age cannot be explained by a shortening in APD₉₀. Less negative RMP and lower upstroke velocity might contribute to lower incidence of AF in women, which may be of clinical relevance.

Detection of Atrial Fibrillation in Routine EEG Recordings

BACKGROUND

A one-channel electrocardiogram (ECG) channel is recommended during electroencephalogram (EEG) recordings principally to help establish ECG or pulse wave contamination of the ECG EEG. However, the ECG recording, in itself, provides useful clinical information, principally the detection of arrhythmias, especially atrial fibrillation (AF), which indicates heart disease that can predispose to embolic stroke and systemic embolism. We sought to determine the prevalence of AF routine recordings in our EEG laboratory in a general hospital.

METHODS

We reviewed the consecutive EEG reports for the past 7 years to determine how often AF was detected in various age groups.

RESULTS

We found AF in 0-0.2% per decade of life until age 60-69 years, 2.7% for 70-79 years, 5% for 80-89 years, and 8% for 90-99 years.

CONCLUSION

We suggest that the ECG trace should be carefully analyzed for AF, especially in patients over 60 years of age. When detected, it should be brought to the referring doctor's attention.

Artificial intelligence-estimated biological heart age using a 12-lead electrocardiogram predicts mortality and cardiovascular outcomes

Background

There is a paucity of data on artificial intelligence-estimated biological electrocardiography (ECG) heart age (AI ECG-heart age) for predicting cardiovascular outcomes, distinct from the chronological age (CA). We developed a deep learning-based algorithm to estimate the AI ECG-heart age using standard 12-lead ECGs and evaluated whether it predicted mortality and cardiovascular outcomes.

Methods

We trained and validated a deep neural network using the raw ECG digital data from 425,051 12-lead ECGs acquired between January 2006 and December 2021. The network performed a holdout test using a separate set of 97,058 ECGs. The deep neural network was trained to estimate the AI ECG-heart age [mean absolute error, 5.8 ± 3.9 years; R-squared, 0.7 (r = 0.84, p < 0.05)].

Findings

In the Cox proportional hazards models, after adjusting for relevant comorbidity factors, the patients with an AI ECG-heart age of 6 years older than the CA had higher all-cause mortality (hazard ratio (HR) 1.60 [1.42-1.79]) and more major adverse cardiovascular events (MACEs) [HR: 1.91 (1.66-2.21)], whereas those under 6 years had an inverse relationship (HR: 0.82 [0.75-0.91] for all-cause mortality; HR: 0.78 [0.68-0.89] for MACEs). Additionally, the analysis of ECG features showed notable alterations in the PR interval, QRS duration, QT interval and corrected QT Interval (QTc) as the AI ECG-heart age increased.

Conclusion

Biological heart age estimated by AI had a significant impact on mortality and MACEs, suggesting that the AI ECG-heart age facilitates primary prevention and health care for cardiovascular outcomes.

Propofol anesthesia decreases the incidence of new-onset postoperative atrial fibrillation compared to desflurane in patients undergoing video-assisted thoracoscopic surgery: A retrospective single-center study

BACKGROUND

Postoperative atrial fibrillation (POAF) increases postoperative morbidity, mortality, and length of hospital stay. Propofol is reported to modulate atrial electrophysiology and the cardiac autonomic nervous system. Therefore, we retrospectively examined whether propofol suppresses POAF in patients undergoing video-assisted thoracoscopic surgery (VATS) compared to desflurane.

METHODS

We retrospectively recruited adult patients who underwent VATS during the period from January 2011 to May 2018 in an academic university hospital. Between continuous propofol and desflurane administration during anesthetic maintenance, we investigated the incidence of new-onset POAF (within 48 hours after surgery) before and after propensity score matching.

RESULTS

Of the 482 patients, 344 received propofol, and 138 received desflurane during anesthetic maintenance. The incidence of POAF in the propofol group was less than that in the desflurane group (4 [1.2%] vs. 8 patients [5.8%], odds ratio [OR]; 0.161, 95% confidence interval (CI), 0.040-0.653, p = 0.011) in the present study population. After adjustment for propensity score matching (n = 254, n = 127 each group), the incidence of POAF was still less in propofol group than desflurane group (1 [0.8%] vs. 8 patients [6.3%], OR; 0.068, 95% CI: 0.007-0.626, p = 0.018).

CONCLUSIONS

These retrospective data suggest propofol anesthesia significantly inhibits POAF compared to desflurane anesthesia in patients undergoing VATS. Further prospective studies are needed to elucidate the mechanism of propofol on the inhibition of POAF.

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.

Association of Uric Acid Albumin Ratio with Recurrence of Atrial Fibrillation after Cryoballoon Catheter Ablation

Objective: Despite improvements in the technology of catheter ablation of atrial fibrillation (AF), recurrences are still a major problem, even after a successful procedure. The uric acid/albumin ratio (UAR), which is an inexpensive and simple laboratory parameter, has recently been introduced in the literature as a predictor of adverse cardiovascular events. Hence, we aimed to investigate the relationship between the UAR and AF recurrence after catheter ablation. Methods: A total of 170 patients who underwent successful catheter ablation for AF were included. The primary outcome was the late recurrence after treatment. The recurrence (+) and recurrence (−) groups were compared for clinical, laboratory and procedural characteristics as well as the predictors of recurrence assessed by regression analysis. Results: In our study population, 53 (26%) patients developed AF recurrence after catheter ablation. Mean UAR was higher in the recurrence (+) group compared to recurrence (−) group (2.4 ± 0.9 vs. 1.8 ± 0.7, p < 0.01). In multivariable regression analysis, left atrial diameter (HR: 1.08, 95% CI: 1.01−1.16, p = 0.01) and UAR (HR:1.36, 95% CI: 1.06−1.75, p = 0.01) were found to be independent predictors of recurrence. In ROC analysis, the UAR > 1.67 predicted recurrence with a sensitivity of 77% and a specificity of 57% (AUC 0.68, p < 0.01). Conclusion: For the first time in the literature, the UAR were found to be correlated independently with AF recurrence after catheter ablation.

Global burden of atrial fibrillation/flutter due to high systolic blood pressure from 1990 to 2019: estimates from the global burden of disease study 2019

Atrial fibrillation/atrial flutter (AF/AFL) has progressed to be a public health concern, and high systolic blood pressure (HSBP) remains the leading risk factor for AF/AFL. This study estimated the HSBP attributable AF/AFL burden based on the data from the Global Burden of Disease (GBD) study 2019. Numbers, age-standardized rates (ASR) of deaths, disability-adjusted life years (DALYs), and corresponding estimated annual percentage change (EAPC) were analyzed by age, sex, sociodemographic index (SDI), and locations. Gini coefficient was calculated to evaluate health inequality. Globally, HSBP-related AF/AFL caused 107 091 deaths and 3 337 876 DALYs in 2019, an increase of 142.5% and 105.9% from 1990, respectively. The corresponding mortality and DALYs ASR declined by 5.8% and 7.7%. High-income Asia Pacific experienced the greatest decrease in mortality and DALYs ASR, whereas the largest increase was observed in Andean Latin America. Almost half of the HSBP-related AF/AFL burden was carried by high and high-middle SDI regions, and it was experiencing a shift to lower SDI regions. A negative correlation was detected between EAPC and SDI. Females and elderly people tended to have a higher AF/AFL burden, whereas young adults (30-49 years old) experienced an annual increase in AF/AFL burden. The Gini index of DALYs rate decreased from 0.224 in 1990 to 0.183 in 2019. Despite improved inequality having been observed over the past decades, the HSBP-related AF/AFL burden varied across regions, sexes, and ages. Cost-effective preventive, diagnostic, and therapeutic tools are required to be implemented in less developed regions.

Connexin Lateralization Contributes to Male Susceptibility to Atrial Fibrillation

Men have a higher risk of developing atrial fibrillation (AF) than women, though the reason for this is unknown. Here, we compared atrial electrical and structural properties in male and female mice and explored the contribution of sex hormones. Cellular electrophysiological studies revealed that action potential configuration, Na+ and K+ currents were similar in atrial myocytes from male and female mice (4–5 months). Immunofluorescence showed that male atrial myocytes had more lateralization of connexins 40 (63 ± 4%) and 43 (66 ± 4%) than females (Cx40: 45 ± 4%, p = 0.006; Cx43: 44 ± 4%, p = 0.002), with no difference in mRNA expression. Atrial mass was significantly higher in males. Atrial myocyte dimensions were also larger in males. Atrial fibrosis was low and similar between sexes. Orchiectomy (ORC) abolished sex differences in AF susceptibility (M: 65%; ORC: 38%, p = 0.050) by reducing connexin lateralization and myocyte dimensions. Ovariectomy (OVX) did not influence AF susceptibility (F: 42%; OVX: 33%). This study shows that prior to the development of age-related remodeling, male mice have more connexin lateralization and larger atria and atrial myocyte than females. Orchiectomy reduced AF susceptibility in males by decreasing connexin lateralization and atrial myocyte size, supporting a role for androgens. These sex differences in AF substrates may contribute to male predisposition to AF.

Higher Na+-Ca2+ Exchanger Function and Triggered Activity Contribute to Male Predisposition to Atrial Fibrillation

Male sex is one of the most important risk factors of atrial fibrillation (AF), with the incidence in men being almost double that in women. However, the reasons for this sex difference are unknown. Accordingly, in this study, we sought to determine whether there are sex differences in intracellular Ca2+ homeostasis in mouse atrial myocytes that might help explain male predisposition to AF. AF susceptibility was assessed in male (M) and female (F) mice (4–5 months old) using programmed electrical stimulation (EPS) protocols. Males were 50% more likely to develop AF. The Ca2+ transient amplitude was 28% higher in male atrial myocytes. Spontaneous systolic and diastolic Ca2+ releases, which are known sources of triggered activity, were significantly more frequent in males than females. The time to 90% decay of Ca2+ transient was faster in males. Males had 54% higher Na+-Ca2+ exchanger (NCX1) current density, and its expression was also more abundant. L-type Ca2+ current (ICaL) was recorded with and without BAPTA, a Ca2+ chelator. ICaL density was lower in males only in the absence of BAPTA, suggesting stronger Ca2+-dependent inactivation in males. CaV1.2 expression was similar between sexes. This study reports major sex differences in Ca2+ homeostasis in mouse atria, with larger Ca2+ transients and enhanced NCX1 function and expression in males resulting in more spontaneous Ca2+ releases. These sex differences may contribute to male susceptibility to AF by promoting triggered activity.

Sex Differences in the Efficacy of Pulmonary Vein Isolation Alone vs. Extensive Catheter Ablation in Patients With Persistent Atrial Fibrillation

BACKGROUND

Women experience more severe arrhythmogenic substrates. This study hypothesized that an extensive ablation strategy, such as linear ablation and/or complex fractionated atrial electrogram (CFAE) ablation in addition to pulmonary vein isolation (PVI-plus), might be effective for women, whereas the PVI alone strategy (PVI-alone) might be sufficient for men to maintain sinus rhythm. The aim of this study was to test this hypothesis.

METHODS AND RESULTS

This study is a post-hoc subanalysis of the EARNEST-PVI trial focusing on sex differences in the efficacies of different ablation strategies. The EARNEST-PVI trial was a prospective, multicenter, randomized, and open-label non-inferiority trial in patients with persistent AF. The primary endpoint was recurrence of AF, atrial flutter, or atrial tachycardia. The EARNEST-PVI trial randomized 376 (76%) men (PVI-alone 186, PVI-plus 190) and 121 (24%) women (PVI-alone 63, PVI-plus 58). The event rate was significantly lower for men and numerically lower for women in the PVI-plus than the PVI-alone group, and there was no interaction between men and women (hazard ratio, 0.641; 95% confidence interval, 0.417-0.985; P value, 0.043 for men vs. hazard ratio, 0.661; 95% confidence interval, 0.352-1.240; P value, 0.197 for women; P value for interaction, 0.989).

CONCLUSIONS

The superiority of the extensive ablation strategy vs. the PVI-alone strategy for persistent AF was consistent across both sexes.

A Systematic Review and Meta-Analysis of Phytoestrogen Protects Against Myocardial Ischemia/Reperfusion Injury: Pre-Clinical Evidence From Small Animal Studies

Background: Phytoestrogens are a class of natural compounds that have structural similarities to estrogens. They have been identified to confer potent cardioprotective effects in experimental myocardial ischemia-reperfusion injury (MIRI) animal models. We aimed to investigate the effect of PE on MIRI and its intrinsic mechanisms. Methods: A systematic search was conducted to identify PEs that have been validated in animal studies or clinical studies as effective against MIRI. Then, we collected studies that met inclusion and exclusion criteria from January 2016 to September 2021. The SYRCLE's RoB tool was used to evaluate the quality. Data were analyzed by STATA 16.0 software. Results: The search yielded 18 phytoestrogens effective against heart disease. They are genistein, quercetin, biochanin A, formononetin, daidzein, kaempferol, icariin, puerarin, rutin, notoginsenoside R1, tanshinone IIA, ginsenoside Rb1, ginsenoside Rb3, ginsenoside Rg1, ginsenoside Re, resveratrol, polydatin, and bakuchiol. Then, a total of 20 studies from 17 articles with a total of 355 animals were included in this meta-analysis. The results show that PE significantly reduced the myocardial infarct size in MIRI animals compared with the control group (p < 0.001). PE treatment significantly reduced the creatine kinase level (p < 0.001) and cTnI level (p < 0.001), increased left ventricular ejection fraction (p < 0.001) and left ventricular fractional shortening (p < 0.001) in MIRI animals. In addition, PE also exerts a significant heart rate lowering effect (p < 0.001). Conclusion: Preclinical evidence suggests that PE can be multi-targeted for cardioprotective effects in MIRI. More large animal studies and clinical research are still needed in the future to further confirm its role in MIRI.

Circulating levels and prognostic cut-offs of sST2, hs-cTnT, and NT-proBNP in women vs. men with chronic heart failure

Aims

To define plasma concentrations, determinants, and optimal prognostic cut‐offs of soluble suppression of tumorigenesis‐2 (sST2), high‐sensitivity cardiac troponin T (hs‐cTnT), and N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) in women and men with chronic heart failure (HF).

Methods and results

Individual data of patients from the Biomarkers In Heart Failure Outpatient Study (BIOS) Consortium with sST2, hs‐cTnT, and NT‐proBNP measured were analysed. The primary endpoint was a composite of 1 year cardiovascular death and HF hospitalization. The secondary endpoints were 5 year cardiovascular and all‐cause death. The cohort included 4540 patients (age 67 ± 12 years, left ventricular ejection fraction 33 ± 13%, 1111 women, 25%). Women showed lower sST2 (24 vs. 27 ng/mL, P < 0.001) and hs‐cTnT level (15 vs. 20 ng/L, P < 0.001), and similar concentrations of NT‐proBNP (1540 vs. 1505 ng/L, P = 0.408). Although the three biomarkers were confirmed as independent predictors of outcome in both sexes, the optimal prognostic cut‐off was lower in women for sST2 (28 vs. 31 ng/mL) and hs‐cTnT (22 vs. 25 ng/L), while NT‐proBNP cut‐off was higher in women (2339 ng/L vs. 2145 ng/L). The use of sex‐specific cut‐offs improved risk prediction compared with the use of previously standardized prognostic cut‐offs and allowed to reclassify the risk of many patients, to a greater extent in women than men, and for hs‐cTnT than sST2 or NT‐proBNP. Specifically, up to 18% men and up to 57% women were reclassified, by using the sex‐specific cut‐off of hs‐cTnT for the endpoint of 5 year cardiovascular death.

Conclusions

In patients with chronic HF, concentrations of sST2 and hs‐cTnT, but not of NT‐proBNP, are lower in women. Lower sST2 and hs‐cTnT and higher NT‐proBNP cut‐offs for risk stratification could be used in women.

Sex disparities in enrollment and reporting of outcomes by sex in contemporary clinical trials of atrial fibrillation

BACKGROUND

Underrepresentation of females in randomized controlled trials (RCTs) limits generalizability and quality of the evidence guiding treatment of females. This study aimed to measure the sex disparities in participants' recruitment in RCTs of atrial fibrillation (AF) and determine associated factors, and to describe the frequency of outcomes reported by sex.

METHODS

MEDLINE was searched to identify RCTs of AF published between January 1, 2011, and November 20, 2021, in 12 top-tier journals. We measured the enrollment of females using the enrollment disparity difference (EDD) which is the difference between the proportion of females in the trial and the proportion of females with AF in the underlying general population (obtained from the Global Burden of Disease). Random-effects meta-analyses of the EDD were performed, and multivariable meta-regression was used to explore factors associated with disparity estimates. We also determined the proportion of trials that included sex-stratified results.

RESULTS

Out of 1133 records screened, 142 trials were included, reporting on a total of 133 532 participants. The random-effects summary EDD was -0.125 (95% confidence interval [CI] = -0.143 to -0.108), indicating that females were under-enrolled by 12.5 percentage points. Female enrollment was higher in trials with higher sample size (<250 vs. >750, adjusted odds ratio [aOR] 1.065, 95% CI: 1.008-1.125), higher mean participants' age (aOR: 1.006, 95% CI: 1.002-1.009), and lower in trials conducted in North America compared to Europe (aOR: 0.945, 95% CI: 0.898-0.995). Only 36 trials (25.4%) reported outcomes by sex, and of these 29 (80.6%) performed statistical testing of the sex-by-treatment interaction.

CONCLUSION

Females remain substantially less represented in RCTs of AF, and sex-stratified reporting of primary outcomes is infrequent. These findings call for urgent action to improve sex equity in enrollment and sex-stratified outcomes' reporting in RCTs of AF.

Sex-linked genetic mechanisms and atrial fibrillation risk

Atrial fibrillation (AF) is a cardiac condition characterised by an irregular heartbeat, atrial pathology and an elevated downstream risk of thrombosis and heart failure, as well as neurological sequelae including stroke and dementia. The prevalence and presentation of, risk factors for, and therapeutic responses to, AF differ by sex, and this sex bias may be partially explained in terms of genetics. Here, we consider four sex-linked genetic mechanisms that may influence sex-biased phenotypes related to AF and provide examples of each: X-linked gene dosage, X-linked genomic imprinting, sex-biased autosomal gene expression, and male-limited Y-linked gene expression. We highlight novel candidate risk genes and pathways that warrant further investigation in clinical and preclinical studies. Understanding the biological basis of sex differences in AF should allow better prediction of disease risk, identification of novel risk/protective factors, and the development of more effective sex-tailored interventions.

The Canadian Women's Heart Health Alliance Atlas on the Epidemiology, Diagnosis, and Management of Cardiovascular Disease in Women - Chapter 5: Sex- and Gender-Unique Manifestations of Cardiovascular Disease

This Atlas chapter summarizes sex- and some gender-associated, and unique aspects and manifestations of cardiovascular disease (CVD) in women. CVD is the primary cause of premature death in women in Canada and numerous sex-specific differences related to symptoms and pathophysiology exist. A review of the literature was done to identify sex-specific differences in symptoms, pathophysiology, and unique manifestations of CVD in women. Although women with ischemic heart disease might present with chest pain, the description of symptoms, delay between symptom onset and seeking medical attention, and prodromal symptoms are often different in women, compared with men. Nonatherosclerotic causes of angina and myocardial infarction, such as spontaneous coronary artery dissection are predominantly identified in women. Obstructive and nonobstructive coronary artery disease, aortic aneurysmal disease, and peripheral artery disease have worse outcomes in women compared with men. Sex differences exist in valvular heart disease and cardiomyopathies. Heart failure with preserved ejection fraction is more often diagnosed in women, who experience better survival after a heart failure diagnosis. Stroke might occur across the lifespan in women, who are at higher risk of stroke-related disability and age-specific mortality. Sex- and gender-unique differences exist in symptoms and pathophysiology of CVD in women. These differences must be considered when evaluating CVD manifestations, because they affect management and prognosis of cardiovascular conditions in women.

Genetic-Guided Pharmacotherapy for Atrial Fibrillation: A Systematic and Critical Review of Economic Evaluations

OBJECTIVES

This study aimed to examine the extent and quality of evidence from economic evaluations (EEs) of genetic-guided pharmacotherapy (PGx) for atrial fibrillation (AF) and to identify variables influential in changing base-case conclusions.

METHODS

From systematic searches, we included EEs of existing PGx testing to guide pharmacotherapy for AF, without restrictions on population characteristics or language. Articles excluded were genetic tests used to guide device-based therapy or focused on animals.

RESULTS

We found 18 EEs (46 comparisons), all model-based cost-utility analysis with or without cost-effectiveness analysis mostly from health system's perspectives, of PGx testing to determine coumadin/direct-acting anticoagulant (DOAC) dosing (14 of 18), to stratify patients into coumadin/DOACs (3 of 18), or to increase patients' adherence to coumadin (1 of 18) versus non-PGx. Most PGx to determine coumadin dosing found PGx more costly and more effective than standard or clinical coumadin dosing (19 of 24 comparisons) but less costly and less effective than standard DOAC dosing (14 of 14 comparisons). The remaining comparisons were too few to observe any trend. Of 61 variables influential in changing base-case conclusions, effectiveness of PGx testing was the most common (37%), accounted for in the models using time-based or medication-based approaches or relative risk. The cost of PGx testing has decreased and plateaued over time.

CONCLUSIONS

EEs to date only partially inform decisions on selecting optimal PGx testing for AF, because most evidence focuses on PGx testing to determine coumadin dosing, but less on other purposes. Future EE may refer to the list of influential variables and the approaches used to account for the effect of PGx testing to inform data collection and study design.

Circulating sex hormones and risk of atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

Sex hormones are associated with many cardiovascular risk factors, but their effects on atrial fibrillation (AF) incidence remain unclear. This systematic review and meta-analysis aimed to evaluate the association of circulating sex hormones with AF risk by pooling available data from observational studies.

METHODS

A systematic literature search for pertinent articles with case-control and cohort designs was conducted via five databases up to 7 July 2021. A meta-analysis with six cohort studies was conducted separately on men and women. Adjusted relative risk (RR) with a 95% confidence interval (CI) was derived by comparing the highest with the lowest levels of a specific sex hormone and by using a random-effect or fixed-effect model. Heterogeneity was tested using the I ² statistic and the Q-test.

RESULTS

A total of six cohort studies and four case-control studies were included. In a meta-analysis of cohort studies, dehydroepiandrosterone sulfate (DHEAS) was associated with a decreased risk of AF in men (RR: 0.729, 95% CI: 0.559-0.952, I ² = 50.0%, P _{-heterogeneity} = 0.157) after combining results from two cohort studies; total testosterone was not associated with any risk of AF in men and postmenopausal women, and AF risk was not associated with estradiol in men after synthesizing available studies.

CONCLUSION

This study indicates that a higher endogenous DHEAS level was associated with a lower AF risk in men, whereas total testosterone and estradiol were not associated with AF risk. Longitudinal studies with multiple monitoring are needed to further promulgate the relationship between various circulating sex hormones and AF risk.

Extensive Left Atrial Low-Voltage Area During Initial Ablation is Associated with A Poor Clinical Outcome Even Following Multiple Procedures

Background

Some patients fail to respond to persistent atrial fibrillation (PeAF) catheter ablation in spite of multiple procedures and ablation strategies, including low voltage area (LVA)-guided, linear, and complex fractionated atrial electrogram (CFAE)-guided ablation procedures. We hypothesized that LVA extent could predict non-responseto Pe AF catheter ablation in spite of multiple procedures.

Methods

This study included 510 patients undergoing initial ablation procedures for PeAF. LVAs were defined as regions with bipolar peak-to-peak voltages of <0.50 mV after PVI during sinus rhythm. Patients were categorized by LVA size into groups A(0-5 cm²), B (5-20 cm²), and C (over 20 cm²). The primary endpoint was AF-free survival after the last procedure.

Results

During a median follow-up of 25 (17, 36) months, AF recurrence was observed in 101 (20%) patients after 1.4±0.6 ablation procedures (maximum 4). Comparison of clinical outcomes after multiple procedures in the three groups showed that the results depended on the extent of LVA. Multivariate analysis of AF-free survival after the last procedure showed that LVAs > 20 cm2 was an independent factor associated with AF recurrence after the final procedure(Hazard ratio, 7.94; 95% confidence interval, 2.91 to 21.67, P <0.001).

Conclusions

Extensive LVA after initial PVI was associated with poor clinical benefit despite multiple catheter based ablations.

Gender-specific association of risk factors in patients who underwent catheter ablation of atrial fibrillation

AIMS

Atrial fibrillation (AF) has been highlighted as a growing epidemic. Evidence is lacking on the role of different risk factors within both genders especially in AF patients referred for catheter ablation (CA). The objective was the evaluation of differences between men and women in the associations with aging, obesity and hypertension as the most highly contributing factors to AF onset and progression.

METHODS

Cases selected among patients scheduled for CA as a rhythm-control strategy and controls from a recent Italian national survey on the population's health conditions were analysed to quantify the strength of association and to assess the existence of gender differences. To reduce the effect of possible confounding factors, both cases and controls were selected without preexisting comorbidities other than hypertension.

RESULTS

At multivariate logistic regression analysis, cases (534 patients, 166 women) were significantly associated with the male sex, higher age, presence of obesity and hypertension in comparison to controls (17,983 subjects, 9,409 women). At analyses gender-stratified, age and obesity had a significant greater association in women than men. On the contrary, hypertension was relatively more frequent in men than women.

CONCLUSION

Although mechanisms linking risk factors and AF are complex, this study suggests the existence of differences mediated by gender in AF drug-refractory patients who underwent CA. A tailored public health programme to reduce the growing burden of AF needs to be designed to prevent and counter the increasing epidemic of the most common cardiac arrhythmia as well as its progression in more resistant forms.

Revealing the Influences of Sex Hormones and Sex Differences in Atrial Fibrillation and Vascular Cognitive Impairment

The impacts of sex differences on the biology of various organ systems and the influences of sex hormones on modulating health and disease have become increasingly relevant in clinical and biomedical research. A growing body of evidence has recently suggested fundamental sex differences in cardiovascular and cognitive function, including anatomy, pathophysiology, incidence and age of disease onset, symptoms affecting disease diagnosis, disease severity, progression, and treatment responses and outcomes. Atrial fibrillation (AF) is currently recognized as the most prevalent sustained arrhythmia and might contribute to the pathogenesis and progression of vascular cognitive impairment (VCI), including a range of cognitive deficits, from mild cognitive impairment to dementia. In this review, we describe sex-based differences and sex hormone functions in the physiology of the brain and vasculature and the pathophysiology of disorders therein, with special emphasis on AF and VCI. Deciphering how sex hormones and their receptor signaling (estrogen and androgen receptors) potentially impact on sex differences could help to reveal disease links between AF and VCI and identify therapeutic targets that may lead to potentially novel therapeutic interventions early in the disease course of AF and VCI.

Sex-related differences of fatty acid-binding protein 4 and leptin levels in atrial fibrillation

AIMS

Adiposity plays a key role in the pathogenesis of atrial fibrillation (AF). Our aim was to study the sex differences in adipokines levels according to AF burden.

METHODS AND RESULTS

Two independent cohorts of patients were studied: (i) consecutive patients with AF undergoing catheter ablation (n = 217) and (ii) a control group (n = 105). (i) Adipokines, oxidative stress, indirect autonomic markers, and leucocytes mRNA levels were analysed; (ii) correlation between biomarkers was explored with heatmaps and Kendall correlation coefficients; and (iii) logistic regression and random forest model were used to determine predictors of AF recurrence after ablation. Our results showed that: (i) fatty acid-binding protein 4 (FABP4) and leptin levels were higher in women than in men in both cohorts (P < 0.01). In women, FABP4 levels were higher on AF cohort (20 ± 14 control, 29 ± 18 paroxysmal AF and 31 ± 17 ng/mL persistent AF; P < 0.01). In men, leptin levels were lower on AF cohort (22 ± 15 control, 13 ± 16 paroxysmal AF and 13 ± 11 ng/mL persistent AF; P < 0.01). (ii) In female with paroxysmal AF, there was a lower acetylcholinesterase and higher carbonic anhydrase levels with respect to men (P < 0.05). (iii) Adipokines have an important role on discriminate AF recurrence after ablation. In persistent AF, FABP4 was the best predictor of recurrence after ablation (1.067, 95% confidence interval 1-1.14; P = 0.046).

CONCLUSION

The major finding of the present study is the sex-based differences of FABP4 and leptin levels according to AF burden. These adipokines are associated with oxidative stress, inflammatory and autonomic indirect markers, indicating that they may play a role in AF perpetuation.

Gut microbiota dysbiosis promotes age-related atrial fibrillation by lipopolysaccharide and glucose-induced activation of NLRP3-inflammasome

AIMS

Aging is the most significant contributor to the increasing prevalence of atrial fibrillation (AF). The gut microbiota dysbiosis is involved in age-related diseases. However, whether the aged-associated dysbiosis contributes to age-related AF is still unknown. Direct demonstration that the aged gut microbiota is sufficient to transmit the enhanced AF susceptibility in a young host via microbiota-intestinal barrier-atria axis has not yet been reported. This study aimed to determine whether gut microbiota dysbiosis affects age-related AF.

METHODS AND RESULTS

Herein, by using a fecal microbiota transplantation (FMT) rat model, we demonstrated that the high AF susceptibility of aged rats could be transmitted to a young host. Specially, we found the dramatically increased levels of circulating lipopolysaccharide (LPS) and glucose led to the up-regulated expression of NLR family pyrin domain containing 3 (NLRP3)-inflammasome, promoting the development of AF which depended on the enhanced atrial fibrosis in recipient host. Inhibition of inflammasome by a potent and selective inhibitor of the NLRP3 inflammasome, MCC950, resulted in a lower atrial fibrosis and AF susceptibility. Then we conducted cross-sectional clinical studies to explore the effect of aging on the altering trends with glucose levels and circulating LPS among clinical individuals in two China hospitals. We found that both of serum LPS and glucose levels were progressively increased in elderly patients as compared with those young. Furthermore, the aging phenotype of circulating LPS and glucose levels, intestinal structure and atrial NLRP3-inflammasome of rats were also confirmed in clinical AF patients. Finally, aged rats colonized with youthful microbiota restored intestinal structure and atrial NLRP3-inflammasome activity, which suppressed the development of aged-related AF.

CONCLUSIONS

Collectively, these studies described a novel causal role of aberrant gut microbiota in the pathogenesis of age-related AF, which indicates that the microbiota-intestinal barrier-atrial NLRP3 inflammasome axis may be a rational molecular target for the treatment of aged-related arrhythmia disease.

TRANSLATIONAL PERSPECTIVE

The current study demonstrates that aged-associated microbiota dysbiosis promotes AF in part through a microbiota-gut-atria axis. Increased AF susceptibility due to enhanced atrial NLRP3-inflammasome activity by LPS and high glucose was found in an aged FMT rat model, and also confirmed within elderly clinical individuals. In a long-term FMT rat study, the AF susceptibility was ameliorated by treatment with youthful microbiota. The present findings can further increase our understanding of aged-related AF and address a promising therapeutic strategy that involves modulation of gut microbiota composition.