2012 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 2010 ESC Guidelines for the management of atrial fibrillation. Developed with the special contribution of the European Heart Rhythm Association

Temporal trends of catheter ablation procedures in patients with atrial fibrillation and atrial flutter: A nationwide cohort study

Background

Catheter ablation is a well-established treatment to prevent atrial fibrillation (AF) and atrial flutter (AFL) recurrences and to relieve symptoms, whereas pacemaker implantation and atrioventricular node (AVN) ablation is used for rate control when medical therapy fails.

Aims

We investigated temporal trends and patient characteristics in catheter ablation procedures for AF, AFL and AVN in Finland between 2012-2018.

Methods

Finnish AntiCoagulation in Atrial Fibrillation (FinACAF) is a registry-based study including all patients with AF or AFL in Finland between 2012-2018.

Results

The number of patients with AF or AFL diagnosis in Finland increased from 185 057 to 243 802 between 2012-2018 and a total of 8954 first-time catheter ablation procedures were performed. Of them, 4909 (54.8 %) were AF ablations, 2731 (30.5 %) AFL ablations and 1314 (14.7 %) AVN ablations. The procedural numbers increased from 457/year to 934/year for AF, from 223/year to 553/year for AFL and from 114/year to 238/year for AVN. Altogether, 0.65% of all patients with diagnosed AF or AFL underwent AF, AFL or AVN ablation in 2018. The mean age of the patients increased in all ablation groups. Patients undergoing AF and AFL ablations were predominantly men (69.7 % and 74.6 % respectively) whereas patients undergoing AVN ablation were more often women (56.9%).

Conclusions

The use of catheter ablation more than doubled during 2012-2018 and the increase was particularly seen in the elderly patients. Nevertheless, only a minority of AF and AFL patients were treated with catheter ablations.

Elevated lipopolysaccharide level is largely driven by time since symptom onset in acute ischemic stroke: the impact on clinical outcomes

BACKGROUND

Gut dysbiosis leading to increased intestinal barrier permeability and translocation of lipopolysaccharide (LPS) in the circulation has been demonstrated in patients with acute myocardial infarction and pulmonary embolism.

OBJECTIVES

We investigated changes in circulating LPS concentrations in acute ischemic stroke (AIS) and their consequences, including prognosis.

METHODS

We studied 98 AIS patients, aged 74 ± 12 years, including 74 (75.5%) thrombolysed individuals. We determined serum LPS and zonulin, a marker of gut permeability, along with protein carbonyl (PC), fibrin clot properties, and thrombin generation on admission, at 24 hours and 3 months. Stroke severity was assessed using the National Institutes of Health Stroke Scale. Stroke functional outcome using modified Rankin scale and stroke-related mortality were evaluated at 3 months.

RESULTS

Serum LPS and zonulin levels on admission were associated with time since symptom onset (r = 0.57; P < .0001; and r = 0.40; P < .0001). Baseline LPS levels correlated with PC (r = 0.51; P < .0001) but not with coagulation and fibrinolysis markers. LPS levels increased at 24 hours in thrombolysed patients (P < .001) and correlated with the National Institutes of Health Stroke Scale score (r = 0.31; P = .002) and PC (r = 0.32; P = .0057). Both LPS and zonulin levels measured at 24 hours increased the odds of having unfavorable modified Rankin scale scores (odds ratio [OR], 1.22; 95% CI, 1.04-1.42; and OR, 2.36; 95% CI, 1.24-4.49 per unit). Elevated LPS level, but not zonulin, was associated with stroke-related mortality (OR, 1.26; 95% CI, 1.02-1.55 per unit).

CONCLUSION

In AIS patients intestinal permeability is mainly driven by increasing time since the symptom onset. Our findings suggest that LPS, with a trend toward its further rise following thrombolysis, adversely affects neurologic functional outcomes and 3-month mortality.

Prevalence of Atrial Fibrillation in Semiurban Nepal: Result From a Community-Based Cross-Sectional Screening

Background: Atrial fibrillation (AF) is a common morbid arrhythmia that can cause thromboembolic events such as stroke. Despite advancements in diagnostic technologies, a significant number of AF patients may remain undetected and undiagnosed, and these asymptomatic patients possess sufficient risk of cardioembolic stroke. Identifying such patients through appropriate screening techniques and timely initiation of systemic anticoagulation therapy is essential to prevent such life-threatening complications. Objectives: The objectives of this study encompass screening of AF among residents of the Dhulikhel Municipality and identifying its prevalence, along with evaluation of stroke risk and use of antithrombotic therapy in patients confirmed with AF. Methods: All residents of four wards of Dhulikhel Municipality, aged 50 years and above (n = 2048), underwent one-time electrocardiogram (ECG) screening using a portable 12-lead ECG machine. The cardiologist checked the cardiogram, and suspected AF cases were referred to the hospital for further evaluation and appropriate management. They were followed up to find out information on disease confirmation and management. Results: Out of 2048 participants, AF was detected in 16 participants, resulting in an overall prevalence of 0.78% (CI 0.4%-1.3%). The prevalence of AF was highest (2.98%) in population aged 80 years and above. Among individuals with AF, the median age was 71.5 (66.3-79.5) years, 50.0% were male and 75.0% had high stroke risk as indicated by a CHA2DS2-VASc score ≥ 2. Among these patients, only 41.66% were treated with oral anticoagulants (OACs), while 58.34% were treated either with single or dual antiplatelet therapy (DAPT). Conclusion: This study provided important insight into the prevalence of AF at the community level. Many AF patients were at high risk of stroke, but the OAC use was less than 50%. Screening of AF needs to be carried out on a larger scale in Nepal for early detection and timely management of the disease.

The 2024 European Society of Cardiology Guidelines for Diagnosis and Management of Atrial Fibrillation: A Viewpoint from a Practicing Clinician's Perspective

Atrial fibrillation (AF) is a complex disease requiring a multidomain and (usually) long-term management, thus posing a significant burden to patients with AF, practitioners, and health care system. Unlike cardiovascular conditions with a narrow referral pathway (e.g., acute coronary syndrome), AF may be first detected by a wide range of specialties (often noncardiology) or a general practitioner. Since timely initiated optimal management is essential for the prevention of AF-related complications, a concise and simple guidance is essential for practitioners managing AF patients, regardless of their specialty. Guideline-adherent management of patients with AF has been shown to translate to improved patient outcomes compared with guideline-nonadherent treatment. To facilitate guideline implementation in routine clinical practice, a good guideline document on AF should introduce only evidence-based new recommendations, while avoiding arbitrary changes, which may be confusing to practitioners. Herein, we discuss the main changes in the 2024 European Society of Cardiology (ESC) AF Guidelines relative to the previous 2020 ESC document. Whether the updates and new recommendations issued by the new guidelines will translate in high adherence in clinical practice (and hence improved prognosis of patients with AF) will need to be addressed in upcoming years.

The Role of Atrial Premature Complexes in Exercise Test in Predicting Atrial Fibrillation in Patients Without Obstructive Coronary Artery Disease

BACKGROUND

Atrial fibrillation (AF) is usually triggered by frequent atrial premature complexes (APC) and atrial tachycardias originated in the pulmonary veins. The aim of the current study is to clarify the relationship between AF and APCs observed during treadmill exercise testing through long-term patient follow-up.

MATERIAL AND METHODS

Our study only examined the data of patients who did not have any obstructive coronary artery disease and had an exercise test. In total, 1559 patients were included in this research. The study data were divided into two groups according to the development of AF during follow-up. The patients who developed any type of AF during the follow-up period were classified as AF (+). Mean follow-up time for AF (+) and (-) groups were 48 and 47 months, respectively.

RESULTS

In the univariable analysis, age, LAAP, and the presence of APCs (HR: 3.906, 95% CI: 2.848-5.365, p < 0.001) during the treadmill exercise test were significantly associated with the development of AF. In the multivariable analysis, age (adjusted HR: 1.063, 95% CI: 1.043-1.083, p < 0.001) and the presence of APCs during the treadmill exercise test (adjusted HR: 2.504, 95% CI: 1.759-3.565, p < 0.001) emerged as independent risk factors for the development of AF. The AF-free survival was significantly lower in the APCs (+) patients compared with the APCs (-) patients (log rank p < 0.001).

CONCLUSION

Our study revealed that individuals without obstructive CAD who exhibited frequent APCs during treadmill exercise tests were more likely to develop AF.

Exploring Inflammatory Markers and Risk Factors Associated with Pericarditis Development after Ablation for Atrial Fibrillation

Background: This study aimed to explore the association between inflammatory markers and the occurrence of post-atrial fibrillation (AF) ablation pericarditis (PAP), while also examining the PAP's incidence and contributing factors. Methods: A retrospective cohort study was conducted between January 2021 and November 2023, including patients who underwent successful AF ablation. Inflammatory markers of interest included the systemic immune-inflammation index (SII), the neutrophil-to-lymphocyte ratio (NLR), and the platelet-to-lymphocyte ratio (PLR). Results: Among the 231 patients examined, 22 (9.52%) were classified as suspected PAP, and 14 (6.06%) as definitive PAP. The median age was 58 years, with no age difference between groups. Males comprised 51.52% of the sample, with male sex frequency significantly higher in the suspected PAP group relative to the other groups (p = 0.007). Multivariable logistic regression indicated that AF duration (p = 0.026) and cavotricuspid isthmus (CTI) ablation (p = 0.001) were associated with definitive PAP, whereas analysis for any pericarditis (suspected or definitive PAP) revealed independent relationships with CTI ablation (p = 0.003) and sleep apnea (p = 0.008). SII, NLR, and PLR were not associated with PAP. Conclusions: Prolonged AF duration, CTI ablation, and sleep apnea are risk factors for PAP. The inflammatory markers (SII, NLR, and PLR) showed no association, warranting further investigation into other markers.

Elevated plasma protein carbonylation increases the risk of ischemic cerebrovascular events in patients with atrial fibrillation: association with a prothrombotic state

INTRODUCTION

Plasma protein carbonylation that reflects oxidative stress has been demonstrated to be associated with the prothrombotic fibrin clot phenotype. However, the role of protein carbonyls (PC) in predicting ischemic stroke in atrial fibrillation (AF) is largely unknown. This study aimed to investigate whether PC increase the risk of stroke in anticoagulated AF patients during follow-up.

METHODS

In 243 AF patients on anticoagulation (median age 69 years; median CHA2DS2-VASc of 4), we measured plasma PC using the assay by Becatti, along with plasma clot permeability (Ks), clot lysis time (CLT), thrombin generation, and fibrinolytic proteins, including plasminogen activator inhibitor type 1 (PAI-1) and thrombin activatable fibrinolysis inhibitor (TAFI). Ischemic stroke, major bleeding, and mortality were recorded during a median follow-up of 53 months.

RESULTS

Plasma PC levels (median, 3.16 [2.54-3.99] nM/mg protein) at baseline showed positive associations with age (P < 0.001), CHA2DS2-VASc (P = 0.003), and N-terminal B-type natriuretic peptide (P = 0.001), but not with type of AF or comorbidities except for heart failure (P = 0.007). PC levels were correlated with CLT (r = 0.342, P < 0.001), endogenous thrombin potential (r = 0.217, P = 0.001) and weakly with Ks (r = -0.145, P = 0.024), but not with fibrinogen, PAI-1, or TAFI levels. Stroke was recorded in 20 patients (1.9%/year), who had at baseline 36% higher PC levels (P < 0.001). Elevated PC (P = 0.003) at baseline were independently associated with stroke risk.

CONCLUSION

Our findings suggest that in patients with AF enhanced protein carbonylation is associated with increased "residual" risk of stroke despite anticoagulation, which is at least in part due to unfavorably altered fibrin clot phenotype.

Positive antiphospholipid antibodies increase the risk of ischemic stroke in patients with atrial fibrillation

BACKGROUND

Antiphospholipid antibodies (aPL), including lupus anticoagulant, antibodies against β2 glycoprotein I (anti-β2GPI), and anticardiolipin (aCL) antibodies are associated with ischemic stroke (IS). Their prevalence and clinical relevance in atrial fibrillation (AF) remain unclear.

OBJECTIVES

To assess whether aPL are associated with increased risk of IS in AF patients despite anticoagulation.

METHODS

We conducted a post hoc analysis of aPL using blood samples from 243 consecutive AF patients enrolled in a cohort study. Markers of a prothrombotic state, including endogenous thrombin potential, fibrin clot permeability, and lysis time, were measured at baseline. During a median follow-up of 52 months, IS/transient ischemic attack and major bleeding were recorded.

RESULTS

We observed aPL at a moderate or high titer in 51 (21%) patients, including 17 (7%) with anti-β2GPI, 19 (7.8%) with aCL antibodies, and 37 (15.2%) with lupus anticoagulant. aPL-positive patients were more likely to have prior stroke (P = .01) and be active smokers (P = .03), along with increased endogenous thrombin potential (P = .02), without any changes in fibrin clot properties. Anti-β2GPI (hazard ratio, 4.38; 95% CI, 1.58-12.19) and aCL (hazard ratio, 4.70; 95% CI, 1.80-12.30) at a moderate or high titer were associated with IS during follow-up (n = 20; 1.9% per year). There were 23 major bleedings (2.1% per year) and 20 deaths (1.9% per year), which were not associated with aPLs.

CONCLUSION

Our study showed a relatively high prevalence of aPL positivity in AF patients, which was linked to an increased risk of IS/transient ischemic attack. This suggests that screening for aPL might help optimize anticoagulant therapy in such patients.

Novel temperature responsive polymer based sealant for embolization

A sealant has been developed that improves upon current catheter-based treatments in the following ways: 1) Efficient delivery system, 2) No in situ polymerization, 3) No harmful byproducts, and 4) Cost-effective formulation. During the development process, particular attention was given to materials that were tunable, safe, and effective sealant agents. The thermo-responsive properties of poly(N-isopropylacrylamide) (PNIPAM) provides an ideal foundation to develop an optimized solution. Through a combination of model-based and material testing, a hydrogel was developed that balances conformational factors to achieve a customized transition temperature, radiopacity suitable for visualization, mechanical properties suitable for delivery via 3Fr catheter, sufficient cohesion once applied to resist migration under physiological pressures and an improved safety profile. Two applications, embolization of lymphatic leakage and exclusions of the left atrial appendage (LAA), to eliminate LAA dead space to reduce the risk of thromboembolic events, were considered. The material and benchtop results for this product demonstrate the suitability of this new material not only for these applications but also for other potential healthcare applications.

Left Atrial Appendage Thrombus as a Marker of Disease Severity in 500 Patients with Atrial Fibrillation on Oral Anticoagulation: A 13-Year Follow-Up Study

Background/Objective: Whether left atrial appendage thrombus (LAAT) in patients with atrial fibrillation (AF) on chronic anticoagulation significantly increases cardiovascular risk is unknown. This study aimed to assess LAAT prevalence and its predictive role in cardiovascular events among consecutive anticoagulated patients with AF admitted for electrical cardioversion. Methods: This prospective study included 500 patients. The primary outcome was LAAT on transesophageal echocardiography. Patients were followed up for a median of 1927.5 (interquartile range 1004-2643) days to assess cardiovascular events. Results: LAAT was detected in 65 (13%) patients. No significant differences in stroke, transient ischemic attack, systemic thromboembolic events, or myocardial infarction prevalence were observed between patients with AF with and without LAAT. Hospitalization for heart failure (HF) was more frequent in patients with LAAT than in those without LAAT; however, the effect of LAAT on HF hospitalization was not statistically significant. Patients with LAAT had a significantly higher risk of cardiovascular death than those without LAAT. LAAT and greater left atrial (LA) diameter were associated with higher rates of cardiovascular death. The independent HF hospitalization predictors were greater LA diameter, lower left ventricular ejection fraction (LVEF), and estimated glomerular filtration rate (eGFR). Conclusions: Patients with AF who received anticoagulation therapy showed a high prevalence of LAAT. LAAT and greater LA diameter were associated with significantly higher rates of cardiovascular death. LAAT, greater LA diameter, lower LVEF, and lower eGFR were associated with poor prognosis in anticoagulated patients with AF and were predictors of disease severity.

Outcomes from a single institution cohort of 248 patients with stage I-III esophageal cancer treated with radiotherapy: Comparison of younger and older populations

Outcomes for patients receiving radiotherapy (RT) for non-metastatic esophageal cancer at a single institution were assessed, as well as the impact of factors including age and intensity modulated RT (IMRT) planning on patient outcomes. A retrospective cohort of patients treated with RT for stage I-III esophageal cancer between 2010 and 2018 was identified. Among 248 identified patients, 28 % identified as older (≥75 years of age). Other than histology, there were no other statistically significant differences in patient and tumour characteristics between the younger and older populations. Treatments varied between the two age groups, with significantly less older patients completing trimodality treatments (17 % vs 58 %). Median overall survival (M-OS) and progression-free survival (M-PFS) were 20 months and 12 months for all patients and 40 months and 26 months for trimodality patients, respectively. In the older patients, the M-OS improved from 13 months for all to 34 months for trimodality patients; and M-PFS from 10 months to 16 months. On multivariate analysis, the use of trimodality therapy showed improved OS (HR 0.26, p < 0.001). In the non-surgical older patient group, significantly better survival was seen in patients who had a heart V30Gy under 46 %. There was no significant difference in M-OS in patients planned with IMRT compared with 3D-conformal RT. Clinical outcomes in the treatment of esophageal cancer vary significantly by treatment approach, with the most favourable results in those receiving trimodality therapy. Among older patients deemed fit after assessment by the multidisciplinary team for trimodality treatments, the M-OS is comparable to the younger patient group.

Evaluation of the management of a first crisis of atrial fibrillation in a group of Cameroon's urban setting subjects

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. When atrial fibrillation is first diagnosed, it tends to be permanent and associated with significant morbidity and mortality. We aimed to study the management of a first episode of atrial fibrillation in a group of patients in Yaounde, Cameroon.

METHODS

We conducted a retrospective study with data collected from the Cardiology department of Yaounde Central Hospital and the internal medicine department of Yaounde General Hospital over five years (January 2017 to December 2021), for a duration of 4 months, from February 2022 to May 2022. All patients older than 15 years with a first episode of atrial fibrillation were included, and all patients with incomplete medical records were excluded. The association between different variables was assessed using a χ² test and logistic regression method with a significance threshold of p < 0.05.

RESULTS

Of the 141 patients recruited, the mean age was 68.5 ± 10.6 years. The sex ratio (M/F) was 0.7. The main associated factors and co-morbidities were hypertension in 70.2% (99) patients, heart failure in 36.9% (52) patients and a sedentary lifestyle in 33.3% (47) patients. The most common anticoagulant treatment was AntiVitamin K, used in 64.5% (91) of patients. Heart rate control was the most commonly used symptom control strategy in 85.1% (120) patients, mainly with beta-blockers in 52.5% (74). We found 1.4% (2) participants who were not treated with antithrombotics as recommended. Treatment of arrhythmia due to co-morbidities was not always recommended. The complication rate was 94.3% (133) patients. Control of the bleeding risk due to antithrombotic therapy and monitoring of anticoagulant therapy were not optimal. The heart rate control strategy had a higher success rate, and the sinus rhythm maintenance rate at one year was 61.7% (37) participants.

CONCLUSION

The management of a first episode of atrial fibrillation at Yaoundé's Central and General Hospitals is not always performed according to current recommendations and is far from optimal. However, nearly two out of three patients maintained sinus rhythm for one year.

[Atrial fibrillation at the Principal Hospital of Dakar, Senegal: outcomes and limits of management]

OBJECTIVES

The aim of the study was to determine the prevalence of AF in the cardiology department of the Hospital Principal of Dakar, then to evaluate the clinical, paraclinical, etiological and evolutionary profiles of AF and finally to identify the limits of its management in our context.

PATIENTS AND METHODS

This was a retrospective, descriptive, analytical, mono-centric study carried out at Hospital Principal of Dakar from January 2019 to August 2021. Were included, all patients admitted for atrial fibrillation, or patients who presented an atrial fibrillation during hospitalization, confirmed by electrocardiogram or long-term electrocardiographic recording during the study period.

RESULTS

The prevalence of atrial fibrillation during the period of our study compared to the hospital population was 7.71%, with a sex ratio of 1.03. The mean age was 67.88 ± 14.09 years. We noted that 83.64% of patients had at least one cardiovascular risk factor, with 56.36% suffering from hypertension, 50.91% of sedentary person and 23.64% of diabetics. Clinically, 92.72% of the patients were symptomatic, with dyspnea predominating (70.91%). Cardiac arrhythmia was present in 85.45% of patients, and congestive heart failure in 47.27%. Long-term electrocardiographic recording was performed in 10 patients, showing 50% of paroxysmal atrial fibrillation. Sixty-three patients (57.27%) had permanent AF, twenty-three patients (20.91%) had persistent AF, fourteen patients (12.73%) had long-term persistent AF and ten patients (9.09%) had paroxysmal AF. Transthoracic echocardiography showed 57.27% of left atrial dilatation and 72.3% of reduced left ventricular ejection fraction. Etiologies for cardiac causes were dominated by dilated cardiomyopathy (21.82%), followed by ischemic heart disease (17.27%). In terms of treatment, the most commonly used molecule was bisoprolol (38.18%), followed by digoxin (21.81%). Anticoagulants were used in 85.46% of cases. Acenocoumarol alone was used in 69.09% of patients. Drug-induced cardioversion was attempted in 2 patients without success, and 4 patients benefited from external electric shock with 3 successes. Most patients had a favorable outcome, but 34.54% suffered hemodynamic complications (18.18%) and thromboembolic ones as well (16.36%). In-hospital mortality in our series was 20%. It was significantly related to heart failure, with a left ventricular ejection fraction < 35% (p < 0.001).

CONCLUSION

Atrial fibrillation is serious because of its hemodynamic, thromboembolic and rhythmic complications. The high mortality is explained by the underlying condition, but also by the delay in management with late diagnosis and, above all, the unavailability of ablation procedures in our context.

Trends in atrial fibrillation-related mortality in Europe, 2008-2019

AIMS

Update data regarding the atrial fibrillation (AF)-related mortality trend in Europe remain scant. We assess the age- and sex-specific trends in AF-related mortality in the European states between the years 2008 and 2019.

METHODS AND RESULTS

Data on cause-specific deaths and population numbers by sex for European countries were retrieved through the publicly available World Health Organization mortality dataset for the years 2008-2019. Atrial fibrillation-related deaths were ascertained when the International Classification of Diseases, 10th Revision code I48 was listed as the underlying cause of death in the medical death certificate. To calculate annual trends, we assessed the average annual % change (AAPC) with relative 95% confidence intervals (CIs) using Joinpoint regression. During the study period, 773 750 AF-related deaths (202 552 males and 571 198 females) occurred in Europe. The age-adjusted mortality rate (AAMR) linearly increased from 12.3 (95% CI: 11.2-12.9) per 100 000 population in 2008 to 15.3 (95% CI: 14.7-15.7) per 100 000 population in 2019 [AAPC: +2.0% (95% CI: 1.6-3.5), P < 0.001] with a more pronounced increase among men [AAPC: +2.7% (95% CI: 1.9-3.5), P < 0.001] compared with women [AAPC: +1.7% (95% CI: 1.1-2.3), P < 0.001] (P for parallelism 0.01). Higher AAMR increases were observed in some Eastern European countries such as Latvia, Lithuania, and Poland, while the lower increases were mainly clustered in Central Europe.

CONCLUSION

Over the last decade, the age-adjusted AF-related mortality has increased in Europe, especially among males. Disparities still exist between Western and Eastern European countries.

Wearable Devices, Health Care Use, and Psychological Well-Being in Patients With Atrial Fibrillation

BACKGROUND

Wearables are increasingly used by patients with atrial fibrillation (AF) for symptom monitoring and health management, but their impact on patient health care use and psychological well-being is not well understood.

METHODS AND RESULTS

In this retrospective, propensity-matched study of patients with AF, survey and electronic health record data were merged to compare AF-specific health care use (outpatient/inpatient visits, rhythm-related testing, and procedures) and informal health care use (telephone calls and patient portal messages) over a 9-month period between wearable users and nonusers. We also examined the effects of wearable cardiac monitoring features (eg, heart rate alerts, irregular rhythm notification, and ECG) on patient behavior and well-being. Of 172 patients with AF in this analysis (age, 72.6±9.0 years; 42% women), 83 used a wearable. Compared with nonusers, wearable users reported higher rates of symptom monitoring and preoccupation (P=0.03) and more AF treatment concerns (P=0.02). Moreover, 20% of wearable users experienced anxiety and always contacted their doctors in response to irregular rhythm notifications. After matching, AF-specific health care use was significantly greater among wearable users compared with nonusers (P=0.04), including significantly higher rates of ECGs, echocardiograms/transesophageal echocardiogram, and ablation. Wearable users were also significantly more likely to use informal health care resources compared with nonusers (P=0.05).

CONCLUSIONS

Wearables were associated with higher rates of symptom monitoring and preoccupation, AF treatment concerns, AF-specific health care use, and use of informal health care resources. Prospective, randomized studies are needed to understand the net effects of wearables and their alerts on patients, providers, and the health care system.

Exploring the bidirectional relationship between sleep disorders and atrial fibrillation: implications for risk stratification and management

BACKGROUND

Atrial fibrillation (AF) is characterized by the absence of p-waves on ECG and irregular rhythm. It often presents with palpitations either palpitations may occur acutely over a short period or intermittently over several years. Other cardinal symptoms of atrial fibrillation include fatigue, dyspnea, and lightheadedness; it is important however to note that most affected individuals are asymptomatic. Concurrently, sleep disorders such as obstructive sleep apnea (OSA), insomnia, narcolepsy, and circadian rhythm disorders which are a group of conditions associated with the body's internal clock that affect the timing of sleep and alertness, are raising concerns due to their potential associations to arrhythmias. This review explores the bidirectional relationship between AF and sleep disorders, highlighting their implications for risk stratification and management strategies.

MAIN BODY

The narrative approach of this review synthesizes evidence from numerous studies obtained through meticulous literature searches. Specific sleep disorders with a bidirectional relationship with AF are the focus, with scrutiny on the prevalence of this connection. The examination delves into the pathophysiology of sleep-related autonomic dysregulation and inflammation, emphasizing potential management modalities. Various meta-analysis cohorts have highlighted a strong connection between sleep disorders and atrial fibrillation (AF). Patients with sleep disorders, especially OSA, have a higher likelihood of developing AF, and conversely, those with AF are more prone to sleep disorders. This impact is not limited to development, as sleep disorders also contribute to the progression of AF, with AF, in turn, negatively impacting sleep duration and quality. Sleep disorders may play an important role in atrial remodeling as well as electrophysiological abnormalities, rendering the atrial tissue more susceptible to arrhythmogenesis. The narrative review suggests that treating sleep disorders could not only improve sleep quality but also reduce risk factors associated with atrial fibrillation. The effective management of sleep disorders emerges as a potential challenge in preventing and treating atrial fibrillation.

CONCLUSION

In conclusion, this narrative study highlights the bidirectional relationship between sleep disorders and atrial fibrillation. There is a positive correlation, affecting the development, progression, and management of atrial fibrillation. The detrimental impact of sleep disorders on atrial remodeling and electrophysiological abnormalities underscores the significance of their diagnosis and treatment. Education about the importance of sleep and the benefits of sleep disorder treatment becomes imperative for patients with AF and sleep disorders.

Pharmacy-Led Management of Atrial Fibrillation: Improving Treatment Adherence and Patient Outcomes

The world's population is ageing, with the number of those over 60 years expected to represent a fifth of the total population by 2050. Increases in chronic long-term health conditions (LTCs) associated with ageing, and requiring regular but often avoidable medical intervention, are pressurising already overloaded, health and social care systems. Atrial fibrillation (AF) is an LTC, which is most frequently diagnosed in the elderly. An often, asymptomatic condition, AF is associated with a 3- to 5-fold increased risk of severe ischemic stroke. Stroke prevention, with risk-stratified oral anticoagulants (OACs) is the standard recommended care for patients with AF. Stroke avoidance is, however, dependent on persistent adherence to OAC medication, with an adherence rate of >80% considered necessary to achieve optimal health outcomes. Suboptimal adherence to OACs is common, with a third of all AF patients not taking their medication as prescribed. This combined with the short half-life of OACs can result in poor clinical outcomes for patients. Policy makers now consider improving adherence to prescribed medicines for LTCs, a public health priority, to ensure better health outcomes for patients, whilst minimising unnecessary health system costs. Prescribing medicines to treat LTCs, such as AF, is not enough, particularly when the patient may not experience any measurable benefit to the treatment and may instead, experience medication-associated adverse events, including a risk of bleeding. Pharmacists who are experts in medicines management are ideally placed to support medication adherence, to educate, and to improve health outcomes for patients with AF. In this review, I will consider the evidence for poor medication adherence in LTCs and in particular adherence to OACs in patients with AF and highlight the role that pharmacists can play in ensuring optimal adherence and showcase pharmacist-led interventions that effectively address this problem.

Public Health Surveillance in Electronic Health Records: Lessons From PCORnet

Introduction

PCORnet, the National Patient-Centered Clinical Research Network, is a large research network of health systems that map clinical data to a standardized data model. In 2018, we expanded existing infrastructure to facilitate use for public health surveillance. We describe benefits and challenges of using PCORnet for surveillance and describe case studies.

Methods

In 2018, infrastructure enhancements included addition of a table to store patients' residential zip codes and expansion of a modular program to generate population health statistics across conditions. Chronic disease surveillance case studies conducted in 2019 assessed atrial fibrillation (AF) and cirrhosis. In April 2020, PCORnet established an infrastructure to support COVID-19 surveillance with institutions frequently updating their electronic health record data.

Results

By August 2023, 53 PCORnet sites (84%) had a 5-digit zip code available on at least 95% of their patient populations. Among 148,223 newly diagnosed AF patients eligible for oral anticoagulant (OAC) therapy, 43.3% were on any OAC (17.8% warfarin, 28.5% any novel oral anticoagulant) within a year of the AF diagnosis. Among 60,268 patients with cirrhosis (2015-2019), common documented etiologies included unknown (48%), hepatitis C infection (23%), and alcohol use (22%). During October 2022 through December 2023, across 34 institutions, the proportion of COVID-19 patients who were cared for in the inpatient setting was 9.1% among 887,051 adults aged 20 years or older and 6.0% among 139,148 children younger than 20 years.

Conclusions

PCORnet provides important data that may augment traditional public health surveillance programs across diverse conditions. PCORnet affords longitudinal population health assessments among large catchments of the population with clinical, treatment, and geographic information, with capabilities to deliver rapid information needed during public health emergencies.

Infective endocarditis associated with left atrial appendage occlusion device: a contemporary systematic review

BACKGROUND

Data are limited regarding infective endocarditis (IE) complicating left atrial appendage occlusion (LAAO) device procedures. This systematic review examines the etiology, diagnosis, and management of infective endocarditis (IE) following LAAO.

METHODS

A comprehensive search of six databases was performed between 2007 and 2022. In selecting studies, articles were included if they provided information about IE complicating LAAO, with relevant clinical and imaging details. Articles were excluded if they were editorials, study protocols, letters, or abstracts.

RESULTS

We identified seven cases of IE complicating LAAO published between 2007 and 2022, from the United States and Europe, highlighting the exceedingly rare reported incidence of the condition. Staphylococcus aureus is the predominant organism implicated in LAAO infections. Echocardiography is a key imaging modality for diagnosing LAAO IE. Both antibiotic therapy and surgical intervention in appropriate patients are important for managing LAAO device-related IE.

CONCLUSIONS

The limited data in the current literature regarding LAAO IE underscores the need for prospective clinical trials to establish evidence-based guidelines for infection prophylaxis, diagnosis, and management. Our findings emphasize the importance of vigilance for device-related infections, especially as the use of LAAO devices continues to grow worldwide.

Direct factor Xa inhibitors and the risk of cancer and cancer mortality: A Danish population-based cohort study

BACKGROUND

Preclinical animal studies have suggested that myeloid cell-synthesized coagulation factor X dampens antitumor immunity and that rivaroxaban, a direct factor Xa inhibitor, can be used to promote tumor immunity. This study was aimed at assessing whether patients with atrial fibrillation taking direct factor Xa inhibitors have lower risk of cancer and cancer-related mortality than patients taking the direct thrombin inhibitor dabigatran.

METHODS AND FINDINGS

This nationwide population-based cohort study in Denmark included adult patients with atrial fibrillation and without a history of cancer, who started taking a factor Xa inhibitor or dabigatran between 2011 and 2015. Data on medical history, outcomes, and drug use were acquired through Danish healthcare registries. The primary outcome was any cancer. Secondary outcomes were cancer-related mortality and all-cause mortality. Outcome events were assessed during 5 years of follow-up in an intention-to-treat analysis. The propensity score-based inverse probability of treatment weighting was used to compute cumulative incidence and subdistribution hazard ratios (SHRs) and corresponding 95% confidence intervals (CIs), with death as a competing event. Propensity scores were estimated using logistic regression and including in the model sex, age group at index date, comorbidities, and use of comedications. A total of 11,742 patients with atrial fibrillation starting a factor Xa inhibitor and 11,970 patients starting dabigatran were included. Mean age was 75.2 years (standard deviation [SD] 11.2) in the factor Xa cohort and 71.7 years (SD 11.1) in the dabigatran cohort. On the basis of the propensity score-weighted models, after 5 years of follow-up, no substantial difference in the cumulative incidence of cancer was observed between the factor Xa inhibitor (2,157/23,711; 9.11%, 95% CI [8.61%,9.63%]) and dabigatran (2,294/23,715; 9.68%, 95% CI [9.14%,10.25%]) groups (SHR 0.94, 95% CI [0.89,1.00], P value 0.0357). We observed no difference in cancer-related mortality (factor Xa inhibitors cohort 1,028/23,711; 4.33%, 95% CI [4.02%,4.68%]. Dabigatran cohort 1,001/23,715; 4.22%, 95% CI [3.83%,4.66%]; SHR 1.03, 95% CI [0.94,1.12]), but all-cause mortality was higher in the factor Xa inhibitor cohort (factor Xa inhibitors cohort 7,416/23,711; 31.31%, 95% CI [30.37%,32.29%]. Dabigatran cohort 6,531/23,715; 27.56%, 95% CI [26.69%,28.45%]; HR 1.17, 95% CI [1.13,1.21]). The main limitations of the study were the possibility of residual confounding and the short follow-up period.

CONCLUSIONS

In this population based cohort study, factor Xa inhibitor use was not associated with an overall lower incidence of cancer or cancer-related mortality when compared to dabigatran. We did observe an increase in all-cause mortality in the factor Xa inhibitor cohort.

Long QT Syndrome With Drugs Used in the Management of Arrhythmias: A Systematic Review

Long QT syndrome (LQTS) is a severe cardiac disorder characterized by an abnormally prolonged QTc interval on an electrocardiogram (ECG), which can result in life-threatening irregular heart rhythms. The use of certain medications, particularly anti-arrhythmic drugs such as quinidine, sotalol, and amiodarone, can lead to acquired LQTS by prolonging the QT interval through the inhibition of specific ion channels responsible for heart repolarization, which may present symptoms like fainting, seizures, and sudden cardiac arrest. This systematic review, conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines, focused on analyzing the association between Long QT syndrome and drugs utilized for managing arrhythmias, involving a thorough examination of six selected studies from an initial pool of 68 articles. It was found that antiarrhythmic drugs such as amiodarone, sotalol, dofetilide, procainamide, quinidine, and flecainide have the potential to cause QT prolongation as a side effect, which is often influenced by factors including dosage, coexisting medical conditions, electrolyte imbalances, and other risk factors. Prolonged QT interval significantly elevates the risk of a life-threatening arrhythmia called torsade de pointes. The management of this side effect typically involves reducing the medication dosage or discontinuing it altogether and, in some cases, employing selective beta blockers. However, further research is essential to improve the understanding and implementation of strategies to prevent and manage QT prolongation caused by antiarrhythmic drugs. Additional clinical studies are warranted to enhance knowledge and provide comprehensive guidelines to healthcare practitioners regarding the appropriate use of these medications. Close monitoring of the QT interval is recommended for patients receiving anti-arrhythmic therapy, and consideration should be given to patient-specific risk factors for LQTS, including age, sex, and electrolyte imbalances.

The Atrial FibriLlatiOn (FLOW-AF) Registry in the Middle East and North Africa: Patient Characteristics, Treatment Patterns and Outcomes

INTRODUCTION

Limited data on atrial fibrillation (AF) are available from the Middle East and North Africa region (MENA). The aim of the FLOW-AF registry was to evaluate the characteristics, treatment patterns, and clinical and economic outcomes of patients with newly diagnosed non-valvular atrial fibrillation (NVAF) in MENA.

METHODS

This multi-center, prospective, observational study (the FLOW-AF registry) enrolled patients newly diagnosed with NVAF across Egypt, Lebanon, Kingdom of Saudi Arabia, and United Arab Emirates. The data collection occurred at enrollment (baseline) and after 6- and 12-months (follow-up). Baseline data included demographics, AF characteristics, medical history, and anti-thrombotic treatment patterns. Clinical events, healthcare resource utilization, and direct costs were collected at follow-up.

RESULTS

The study enrolled a total of 1418 patients (52.7% males and 47.3% females). The mean age of the patients was 64.5 years and 90.6% were white. The mean (standard deviation) CHA2DS2-VASc and HAS-BLED risk scores were 2.7 (1.6) and 1.6 (1.2), respectively. Non-vitamin K antagonist oral anticoagulants, antiplatelet therapy, and vitamin K antagonists were prescribed to 65.8%, 16.4%, and 12.9% patients, respectively. During follow-up, the following rates of clinical outcomes were observed: bleeding events (1.7%), transient ischemic attack (1.7%), all-cause mortality (1.7%), stroke (0.6%), myocardial infarction (0.2%), and systemic embolism (0.08%).

CONCLUSIONS

This MENA patient population was younger and had lower mean baseline CHA2DS2-VASc and HAS-BLED scores. The rates of clinical outcomes over 1-year in this study were low. Longer follow-up is required to comprehensively assess clinical outcomes in this patient population.

Seeking help for atrial fibrillation: the role of the body in distributed decision making

We adopt Rapley's (2008) concept of distributed decision making to explore the role of the body in people's decisions to seek medical care. We conducted in-depth interviews with patients diagnosed with atrial fibrillation (AF) who were taking long-term anticoagulants to prevent stroke. We interviewed seventeen patients recruited from English anticoagulant clinics using the biographic-narrative-interpretive method, and conducted thematic, structural and metaphorical analyses. This pluralistic analysis focused on how distributed decision-making was enacted through a range of socio-material, relational and embodied practices. Participants told how they experienced AF-related sensations that fluctuated in intensity and form. Some had no symptoms at all; others experienced sudden incapacitation - these experiences shaped different journeys towards seeking medical help. We draw on work by Mol (2002) to show how the body was differently observed, experienced and done across contexts as the narratives unfolded. We show that as part of a relational assemblage, involving social, material and technological actors over time, a new body-in-need-of-help was enacted and medical help sought. This body-in-need-of-help was collectively discussed, interpreted and experienced through distribution of body parts, fluids and technological representations to shape decisions. RAPLEY T., 2008. Distributed decision making: the anatomy of decisions-in-action. Sociology of Health & Illness, 30, 429-444. MOL A., 2002. The body multiple: ontology in medical practice. Duke University Press: Durham.

Trends in the Use of Medications for Secondary Ischemic Stroke Prevention in Denmark, 2005-2021

BACKGROUND AND OBJECTIVES

Understanding trends in the use of medications for secondary stroke prevention is crucial for identifying areas for improvement in stroke care. We examined the use of lipid-lowering, antihypertensive, glucose-lowering, oral anticoagulant, and antiplatelet medications after ischemic stroke hospitalization, from 2005 to 2021.

METHODS

Using nationwide registries in Denmark, we identified a cohort of patients discharged from hospital with a first-time or recurrent ischemic stroke (N = 150,744). Stratified by calendar year, we ascertained the 180-day probability of filling a prescription for the abovementioned medications after discharge. We further assessed factors associated with medication use.

RESULTS

From 2005 to 2021, lipid-lowering medication use increased from 58.3% to 82.0%; atorvastatin use rose from 2.1% to 64.8% and simvastatin use decreased from 55.7% to 8.6%. Antihypertensive medication use remained stable, at approximately 89%, and various antihypertensive classes were used comparably. Glucose-lowering medication use increased from 71.5% in 2005 to 84.1% in 2021, driven primarily by an increase in metformin use (from 28.0% to 59.5%). Use of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors continually increased (from 1.7% to 17.5% and from 0.5% to 17.3%, respectively) between 2015 and 2021. Anticoagulant medication use rose from 45.9% in 2005 to 87.0% in 2021, primarily because of increased use of direct oral anticoagulant medications starting around 2010 and a decline in warfarin use. Antiplatelet use remained consistently high, at approximately 95%. Trends were consistent across subgroups of interest; however, overall medication use was lower in older patients (65 years and older), patients with severe stroke, and patients with neurologic and psychiatric comorbidities.

DISCUSSION

Despite increasing trends in the use of 3 of 5 medication classes, the overall use of lipid-lowering, glucose-lowering, and oral anticoagulant medications was somewhat lower than expected according to clinical guidelines, particularly among older patients with more severe stroke and other comorbidities. The relatively low use in these subgroups may signify appropriate clinical decision making in consideration of frequent contraindications and reduced life expectancy or highlight potential areas of improvement for the care of patients with recent ischemic stroke.

Chinese Society of Cardiology guidelines on the diagnosis and treatment of adult fulminant myocarditis

Fulminant myocarditis is an acute diffuse inflammatory disease of myocardium. It is characterized by acute onset, rapid progress and high risk of death. Its pathogenesis involves excessive immune activation of the innate immune system and formation of inflammatory storm. According to China's practical experience, the adoption of the "life support-based comprehensive treatment regimen" (with mechanical circulation support and immunomodulation therapy as the core) can significantly improve the survival rate and long-term prognosis. Special emphasis is placed on very early identification,very early diagnosis,very early prediction and very early treatment.

Atrial fibrillation post CABG and the risk of arrhythmia recurrence: the AFRODITE study

BACKGROUND

New-onset postoperative atrial fibrillation (POAF) after coronary artery bypass surgery (CABG) occurs with an incidence of 20-40%. The clinical relevance of POAF remains a concern, and the need for further studies regarding the clinical management of POAF is necessary.

AIM

The AFRODITE study, a prospective multicenter cohort study, had as its primary endpoint the evaluation of AF recurrence in patients post CABG over a one-year period.

METHODS

Two hundred twenty-eight patients aged >50 years who underwent isolated CABG were included in the study. Patients were stratified into two groups, POAF and non-POAF, and followed for 12 months for AF recurrence, hospitalizations, and death.

RESULTS

Two hundred twenty-eight patients (mean age 67 years, 88.6% male) were included in the study. 28.5% of patients experienced at least one episode of POAF during index hospitalization (POAF group) and were compared with the non-POAF group (n = 163). Multivariate stepwise logistic regression analysis showed that the strongest prognostic parameter for POAF was the CHA2DS2-VASc score (odds ratio = 1.61, p < 0.001). POAF patients had a worse in-hospital outcome, but the incidence of long-term AF recurrence was not statistically different (3.6% vs. 4.8%, p = 0.9).

CONCLUSION

Interestingly, a one-year prospective follow-up of patients in the study did not reveal significant differences between POAF and non-POAF patients. A notable finding was that patients with a higher CHA2DS2-VASc score were more likely to develop POAF.

Early Detection of Atrial Fibrillation in Chronic Obstructive Pulmonary Disease Patients

Atrial fibrillation (AF) is an important medical problem, as it significantly affects patients' quality of life and prognosis. AF often complicates the course of chronic obstructive pulmonary disease (COPD), a widespread disease with heavy economic and social burdens. A growing body of evidence suggests multiple links between COPD and AF. This review considers the common pathogenetic mechanisms (chronic hypoxia, persistent inflammation, endothelial dysfunction, and myocardial remodeling) of these diseases and describes the main risk factors for the development of AF in patients with COPD. The most effective models based on clinical, laboratory, and functional indices are also described, which enable the identification of patients suffering from COPD with a high risk of AF development. Thus, AF in COPD patients is a frequent problem, and the search for new tools to identify patients at a high risk of AF among COPD patients remains an urgent medical problem.

Tachy-brady syndrome: Electrophysiology and evolving principles of management

Sudden alterations in the heart rate may be associated with diverse symptoms. Sinus node dysfunction (SND), also known as sick sinus syndrome, is a sinoatrial (SA) node disorder. SND is primarily caused by the dysfunction of the pacemaker, as well as impaired impulse transmission resulting in a multitude of abnormalities in the heart rhythms, such as bradycardia-tachycardia, atrial bradyarrhythmias, and atrial tachyarrhythmias. The transition from bradycardia to tachycardia is generally referred to as "tachy-brady syndrome" (TBS). Although TBS is etiologically variable, the manifestations remain consistent throughout. Abnormal heart rhythms have the propensity to limit tissue perfusion resulting in palpitations, fatigue, lightheadedness, presyncope, and syncope. In this review, we examine the physiology of tachy-brady syndrome, the practical approach to its diagnosis and management, and the role of adenosine in treating SND.

Potentially inappropriate prescribing in multimorbid and polymedicated older adults with AF: A Systematic Review and Meta-Analysis

AIM

Polypharmacy in multimorbid older patients with atrial fibrillation (AF) is a risk factor for potentially inappropriate prescribing (PIP). We aimed to systematically assess the evidence on the prevalence of PIP and its impact on adverse health outcomes in this patient group.

METHODS

A systematic search of the published peer-reviewed literature describing the prevalence of PIP and/or its association with adverse health outcomes in multimorbid (AF plus one comorbidity) and polymedicated (≥ 2 drugs) adults ≥ 65 years was done up to March 2023. A meta-analysis of the prevalence of PIP of (direct) oral anticoagulants ((D)OACs) was conducted using a random-effects model. Leave-one-out analysis was performed with R (version 4.2.2) and RStudio (version 2022.12.0+353).

RESULTS

Of the 12 studies included, only one reported on the prevalence of overall PIP (65%). The meta-analysis of 10 studies assessing PIP of (D)OACs produced a pooled prevalence [95% confidence interval (CI)] of 35% [30-40%], with significant heterogeneity between the included studies (I2 95%). No statistically significant association was reported in three studies between PIP of (D)OACs, cardiovascular (CV) and all-cause mortality, hospital readmission, CV hospitalisation and stroke. Reported associations between PIP and major bleeding differed, with one study demonstrating a significant association (odds ratio 2.17; 95% CI 1.14-4.12) and the other study not showing such association.

CONCLUSION

This systematic review highlights the scarce evidence regarding the prevalence of PIP and its association with adverse health outcomes in multimorbid older adults with AF. Large, prospective and better-designed studies are needed.

Asymptomatic vs. symptomatic atrial fibrillation: Clinical outcomes in heart failure patients

BACKGROUND

The outcome implications of asymptomatic vs. symptomatic atrial fibrillation (AF) in specific groups of patients according to clinical heart failure (HF) and left ventricular ejection fraction (LVEF) need to be clarified.

METHODS

In a prospective observational study, patients were categorized according to overt HF with LVEF≤40 %, or with LVEF>40 %, or without overt HF with LVEF40 %≤ or > 40 %, as well as according to the presence of asymptomatic or symptomatic AF.

RESULTS

A total of 8096 patients, divided into 8 groups according to HF and LVEF, were included with similar proportions of asymptomatic AF (ranging from 43 to 48 %). After a median follow-up of 730 [699 -748] days, the composite outcome (all-cause death and MACE) was significantly worse for patients with asymptomatic AF associated with HF and reduced LVEF vs. symptomatic AF patients of the same group (p = 0.004). On adjusted Cox regression analysis, asymptomatic AF patients with HF and reduced LVEF were independently associated with a higher risk for the composite outcome (aHR 1.32, 95 % CI 1.04-1.69) and all-cause death (aHR 1.33, 95 % CI 1.02-1.73) compared to symptomatic AF patients with HF and reduced LVEF. Kaplan-Meier curves showed that HF-LVEF≤40 % asymptomatic patients had the highest cumulative incidence of all-cause death and MACE (p < 0.001 for both).

CONCLUSIONS

In a large European cohort of AF patients, the risk of the composite outcome at 2 years was not different between asymptomatic and symptomatic AF in the whole cohort but adverse implications for poor outcomes were found for asymptomatic AF in HF with LVEF≤40 %.

Network Pharmacology and Bioinformatics Analyses Identify the Core Genes and Pyroptosis-Related Mechanisms of Nardostachys Chinensis for Atrial Fibrillation

BACKGROUND

Nardostachys chinensis is an herbal medicine widely used in the treatment of atrial fibrillation (AF), but the mechanism is unclear.

OBJECTIVE

To explore the molecular mechanism of N. chinensis against AF.

METHODS

The TCMSP was used to screen the active N. chinensis compounds and their targets. Differentially expressed genes (DEGs) for AF were identified using open-access databases. Using Venn diagrams, the cross-targets of N. chinensis, pyroptosis, and AF were obtained. The genes underwent molecular docking as well as gene set enrichment analysis (GSEA). A nomogram based on candidate genes was constructed and evaluated with the clinical impact curve. After that, the immune infiltration of the dataset was analyzed by single sample GSEA (ssGSEA). Finally, microRNAs (miRNAs) and transcription factors (TFs) were predicted based on candidate genes.

RESULTS

Tumor necrosis factor (TNF) and caspase-8 (CASP8) were obtained as candidate genes by taking the intersection of DEGs, targets of N. chinensis, and pyroptosis-related genes. Tolllike receptor (TLR) and peroxisome proliferator-activated receptor (PPAR) signaling pathways were linked to candidate genes. Additionally, immune cell infiltration analysis revealed that CASP8 was associated with natural killer T cells, natural killer cells, regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSC), macrophages, CD8 T cells, and CD4 T cells. Finally, miR-34a-5p and several TFs were found to regulate the expression of CASP8 and TNF.

CONCLUSION

CASP8 and TNF are potential targets of N. chinensis intervention in pyroptosisrelated AF, and the TLR/NLRP3 signaling pathway may be associated with this process.

Coagulation Factor Xa Has No Effects on the Expression of PAR1, PAR2, and PAR4 and No Proinflammatory Effects on HL-1 Cells

Atrial fibrillation (AF), characterised by irregular high-frequency contractions of the atria of the heart, is of increasing clinical importance. The reasons are the increasing prevalence and thromboembolic complications caused by AF. So-called atrial remodelling is characterised, among other things, by atrial dilatation and fibrotic remodelling. As a result, AF is self-sustaining and forms a procoagulant state. But hypercoagulation not only appears to be the consequence of AF. Coagulation factors can exert influence on cells via protease-activated receptors (PAR) and thereby the procoagulation state could contribute to the development and maintenance of AF. In this work, the influence of FXa on Heart Like-1 (HL-1) cells, which are murine adult atrial cardiomyocytes (immortalized), was investigated. PAR1, PAR2, and PAR4 expression was detected. After incubations with FXa (5-50 nM; 4-24 h) or PAR1- and PAR2-agonists (20 µM; 4-24 h), no changes occurred in PAR expression or in the inflammatory signalling cascade. There were no time- or concentration-dependent changes in the phosphorylation of the MAP kinases ERK1/2 or the p65 subunit of NF-κB. In addition, there was no change in the mRNA expression of the cell adhesion molecules (ICAM-1, VCAM-1, fibronectin). Thus, FXa has no direct PAR-dependent effects on HL-1 cells. Future studies should investigate the influence of FXa on human cardiomyocytes or on other cardiac cell types like fibroblasts.

Clinical Features and Impact on One Year Prognosis of Prescribing Low Doses of Direct Oral Anticoagulant Agents in a Middle Eastern Population with Atrial Fibrillation: Analysis from the Jordan Atrial Fibrillation Study

Introduction

Direct oral anticoagulant agents (DOACs) are indicated for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF). Reduced doses of DOACs are indicated in patients who have renal impairment and according to age and weight criteria. The aim of this study was to investigate the frequency, clinical factors, and impact on 1-year prognosis of underdosing DOACs.

Methods

Data of patients enrolled in the Jordan AF (JoFib) study and who were followed for 1 year was used to compare patients prescribed standard dose with those who were underdosed.

Results

There were 672 patients (76.2%) who were prescribed standard dose and 210 patients (23.8%) who were underdosed. Baseline characteristics were similar between the 2 groups. Factors associated with underdosing were enrollment from an outpatient vs hospital site, moderate- or high-risk HAS-BLED score, an abnormal left ventricular ejection fraction (LVEF <50%), a history of heart failure, or current use of diuretics. At 1 year, the incidence of all-cause mortality was 12.2% in standard dose vs 13.3% in the underdose group (P = .82), stroke or systemic embolism was 3.6% in the standard dose vs 3.8% in the underdose group (P = .67), and major bleeding was 2.2% in the standard dose vs 3.3% in the underdose group (P = .35).

Conclusions

About (25%) of patients were underdosed. Factors associated with underdosing were outpatient (vs hospital) center enrollment, moderate- or high-risk HAS-BLED score, abnormal LVEF (<50%), history of heart failure, and current use of diuretics. There were no significant differences in the incidence of adverse events of mortality and major morbidity at 1-year follow-up between the standard dose and the underdose groups.

Acute stroke in patients taking an oral anticoagulant: impact of clinical pharmacist's intervention on pharmacovigilance reporting

INTRODUCTION

Ischemic or hemorrhagic stroke can occur to patients treated with oral anticoagulants (OAC), through lack of effectiveness or overdosing.

OBJECTIVE

To evaluate the impact of clinical pharmacist's intervention on pharmacovigilance (PV) reporting for OAC-treated patients hospitalized for stroke.

METHODS

Monocentric prospective study in which a clinical pharmacist's intervention was performed in a stroke unit, with a focus on patients treated by OAC prior admission. A PV report was made with all data collected for cases of stroke suspected to be related to OAC therapy. Data provided by pharmacist were compared with data initially available in the patient's electronic medical records. PV reports with pharmacist intervention were compared to those without.

RESULTS

During the study period, 48 patients were included in the study: 43 (89.6%) ischemic strokes with an embolic or unknown etiology, four hemorrhage strokes (8.33%), and one medication error (2.08%). A clinical pharmacist intervention was performed for 19 patients (39.6%) and provided significant additional data in all of them (100%). The information was related to adherence to treatment for 17 cases (89.5%), OAC's initial prescription date for 11 cases (57.9%) and identifying event(s) that could have interfered with the efficacy of the OAC in five cases (26.3%). For patients with pharmacist intervention, PV reports were significantly more informative in terms of date's introduction of anticoagulant, adherence to treatment, reference to weight change or concomitant event.

CONCLUSIONS

clinical pharmacist's intervention with patients taking oral anticoagulants and hospitalized for acute stroke contributes to collect high-quality data for pharmacovigilance reporting.

Left atrial appendage occlusion in an older population cohort

BACKGROUND

Atrial fibrillation is the most common cardiac arrhythmia and is a major risk factor for stroke, with an incidence rate of 4-5% per year. The use of DOACs is recommended for specific patient populations however the risk of bleeding commonly precludes their use. Left atrial appendage occlusion is a relatively novel procedure recommended for such patients. We set out to analyse the initial success and safety of this procedure in a single site.

RESULTS

Twenty patients were included in the study with an average age of 81 years. Seventy percent (n = 14) were male. Ninety percent (n = 18) had a history of major bleeding, an absolute contraindication to anticoagulation. The mean CHADS2VaSc and HASBLED scores were 4.75 and 3.7, respectively. The technical success rate was 95% comparable with existing data. The procedural success rate in our study was 80%. The most frequent complication was cardiac tamponade, occurring in 10% of cases.

CONCLUSION

We report lower technical success and procedural success rates in an older population cohort than historically studied, 90% of whom had an absolute contraindication to oral anticoagulation, with higher CHADS2VaSc and HASBLED scores than commonly studied.

Heterogeneity of outcomes within diabetic patients with atrial fibrillation on edoxaban: a sub-analysis from the ETNA-AF Europe registry

BACKGROUND

Recent data have suggested that insulin-requiring diabetes mostly contributes to the overall increase of thromboembolic risk in patients with atrial fibrillation (AF) on warfarin. We evaluated the prognostic role of a different diabetes status on clinical outcome in a large cohort of AF patients treated with edoxaban.

METHODS

We accessed individual patients' data from the prospective, multicenter, ETNA-AF Europe Registry. We compared the rates of ischemic stroke/transient ischemic attack (TIA)/systemic embolism, myocardial infarction (MI), major bleeding and all-cause death at 2 years according to diabetes status.

RESULTS

Out of an overall population of 13,133 patients, 2885 had diabetes (22.0%), 605 of whom (21.0%) were on insulin. The yearly incidence of ischemic stroke/TIA/systemic embolism was 0.86% in patients without diabetes, 0.87% in diabetic patients not receiving insulin (p = 0.92 vs no diabetes) and 1.81% in those on insulin (p = 0.002 vs no diabetes; p = 0.014 vs diabetes not on insulin). The annual rates of MI and major bleeding were 0.40%, 0.43%, 1.04% and 0.90%, 1.10% and 1.71%, respectively. All-cause yearly mortality was 3.36%, 5.02% and 8.91%. At multivariate analysis, diabetes on insulin was associated with a higher rate of ischemic stroke/TIA/systemic embolism [adjusted HR 2.20, 95% CI 1.37-3.54, p = 0.0011 vs no diabetes + diabetes not on insulin] and all-cause death [aHR 2.13 (95% CI 1.68-2.68, p < 0.0001 vs no diabetes]. Diabetic patients not on insulin had a higher mortality [aHR 1.32 (1.11-1.57), p = 0.0015], but similar incidence of stroke/TIA/systemic embolism, MI and major bleeding, vs those without diabetes.

CONCLUSIONS

In a real-world cohort of AF patients on edoxaban, diabetes requiring insulin therapy, rather than the presence of diabetes per se, appears to be an independent factor affecting the occurrence of thromboembolic events during follow-up. Regardless of the diabetes type, diabetic patients had a lower survival compared with those without diabetes.

Protein Carbonylation Contributes to Prothrombotic Fibrin Clot Phenotype in Acute Ischemic Stroke: Clinical Associations

BACKGROUND

Acute ischemic stroke (AIS) is associated with enhanced oxidative stress and unfavorably altered fibrin clot properties. We investigated determinants of plasma protein carbonylation (PC) in AIS, its impact on the prothrombotic state, and prognostic value during follow-up.

METHODS

We included 98 consecutive AIS patients aged 74±12 years (male:female ratio, 50:48 [51%:49%]) at the Neurology Center in Warsaw, Poland, between January and December 2014. As many as 74 (75.5%) patients underwent thrombolysis, and 24 were unsuitable for thrombolysis. We determined plasma PC, along with thrombin generation, fibrin clot permeability, and clot lysis time on admission, at 24 hours, and 3 months. Stroke severity was assessed using the National Institutes of Health Stroke Scale and stroke outcome with the modified Rankin Scale. Hemorrhagic transformation was assessed on the computed tomography scan within 48 hours from the symptom onset, while stroke-related mortality was evaluated at 3 months.

RESULTS

On admission, PC levels (median, 4.61 [3.81-5.70] nM/mg protein) were associated with the time since symptom onset (r=0.41; P<0.0001) and with the National Institutes of Health Stroke Scale score (P=0.36; P=0.0003). Higher PC levels on admission correlated with denser fibrin clot formation and prolonged clot lysis time but not with thrombin generation. In thrombolysed patients, lower PC levels were observed after 24 hours (-34%) and at 3 months (-23%; both P<0.001). PC levels at baseline and after 24 hours predicted the modified Rankin Scale score >2 at 3 months (OR, 1.90 [95% CI, 1.21-3.00]; OR, 2.19 [95% CI, 1.39-3.44], respectively). Higher PC at baseline predicted hemorrhagic transformation of stroke (OR, 1.95 [95% CI, 1.02-3.74]) and stroke-related mortality (OR, 2.02 [95% CI, 1.08-3.79]), while higher PC at 24 hours predicted solely stroke-related mortality (OR, 2.11 [95% CI, 1.28-3.46]).

CONCLUSIONS

Elevated plasma PC levels in patients with AIS, related to prothrombotic fibrin clot properties, are associated with stroke severity. Thrombolysis reduces the extent of PC. The current study suggests a prognostic value of PC in AIS.

Limitations in Contemporary Pharmacological Stroke Prevention Therapies in Atrial Fibrillation: A Descriptive Literature Review

The most common arrhythmia, atrial fibrillation (AF), increases with age and is associated with a 5-fold increased risk of stroke. Although lifelong oral anticoagulation (OAC) is strongly recommended for stroke prevention in patients with AF and CHA2DS2-VASc ≥ 2 only 50-60% of patients in Western countries belonging to this group are treated with oral anticoagulants, and less than half of these adhere to therapy over time. Before 2010, the numerous limitations associated with vitamin K antagonists (VKAs) were considered to be the reason behind OAC underuse; however, the approval of direct oral anticoagulants (DOACs) that require once- or twice-daily intake, no regular blood tests and fewer drug-food interactions has resulted in only modest improvements in OAC use and adherence.

Predictive Values of the CHA2DS2-VASc Score and Left Atrial Diameter for Cerebral Small Vessel Disease in Geriatric Patients With Atrial Fibrillation

Objective The objective of this study was to determine whether the CHA2DS2-VASc (congestive heart failure, hypertension, age, diabetes mellitus, stroke, vascular disease, age, sex) score and left atrial diameter (LAD) could predict the presence of cerebral small vessel disease (cSVD) in patients older than 65 years with atrial fibrillation as the cause of ischemic stroke. Materials and methods In this study, we included patients over 65 years of age who had suffered an ischemic stroke caused by atrial fibrillation within 30 days after the onset of symptoms. The data recorded included demographics, electrocardiograms, Holter monitors, and echocardiography reports. The anteroposterior LAD, determined by transthoracic echocardiography, was analyzed. Each patient's CHA2DS2-VASc score was calculated. Brain magnetic resonance imaging (MRI) assessed white matter hyperintensities (WMH) on fluid-attenuated inversion recovery (FLAIR) images and cerebral microbleeds (CMBs) on susceptibility-weighted sequences. The Fazekas score, based on WMH on MRI, was used to grade the severity of gliosis. Participants were categorized into three groups according to their quantitative CMB burden. Findings The study included 60 participants, with a mean age of 80 years (range 65-99), and 43.3% (n = 26) were male. The CHA2DS2-VASc score had a mean value of 4.21 (range 2-8), and the mean LAD was 4.17 (range 2.6-5.3) cm. The CHA2DS2-VASc score did not predict CMBs (OR, 1.389; 95% CI, 0.961-2.008, p = 0.08) in geriatric stroke patients with atrial fibrillation. However, in the subgroup of patients with diabetes mellitus, the CHA2DS2-VASc score was higher in those with CMB 1-4 and CMB ≥ 5 than in those without CMB. Additionally, the risk of CMBs 1-4 increased with higher LAD compared to patients without LAD. Conclusion The LAD and CHA2DS2-VASc scores were not significantly associated with CMB prediction in elderly stroke patients with atrial fibrillation. In a diabetes mellitus subgroup, the CHA2DS2-VASc score was indicative of CMB. An increased LAD elevates the risk of CMBs in patients with coronary artery disease.

Impact of left atrial appendage closure in patients on anticoagulation for atrial fibrillation and recurrent or chronic gastrointestinal bleeding

BACKGROUND

Oral anticoagulation in non-valvular atrial fibrillation is associated with an increased risk of bleeding, particularly gastrointestinal bleeding, leading to treatment withdrawal in up to 50% of patients and putting them at risk of embolic events. Left atrial appendage closure (LAAC) can be an alternative to chronic anticoagulation. We aim to describe the impact of LAAC in patients with gastrointestinal bleeding (GIB) or chronic iron deficiency anaemia (CIDA) on healthcare resources consumption.

METHODS

Observational retrospective study of patients who underwent LAAC for GIB or CIDA at a single centre.

RESULTS

Nineteen patients with a median age of 74 years and a median Charlson score of six points were included in the study. Angiodysplasias were the most frequent cause of GIB or CIDA. The procedural success rate of LAAC was 100% with a median anticoagulant and antiplatelet treatment duration of 92 days. One year after the LAAC, we found a significant improvement in the lowest haemoglobin concentration and a reduction in the number of red blood cells transfusion, hospital admissions due to GIB and CIDA and the number of endoscopic examinations. One patient died due to a pulmonary thromboembolism. No deaths related to GIB were observed.

CONCLUSIONS

LAAC seems to be a safe and effective alternative to anticoagulation in patients with GIB or CIDA.

Association of Atrial Fibrillation Recurrence with Right Coronary Atherosclerosis and Increased Left Arterial Epicardial Fat Following Catheter Ablation-Results of a Multimodality Study

BACKGROUND

Identification of predictors for atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) can lead to better long-term results. Our aim was to investigate the association between novel CT imaging markers reflecting the severity of coronary atherosclerosis and the risk of recurrence following PVI.

METHODS

This study included 80 patients with paroxysmal/persistent AF who underwent PVI. The patients were divided into two groups: Group 1-23 patients with recurrence and Group 2-57 patients without recurrence.

RESULTS

Patients with recurrence presented with a more enlarged left atrial diameter and reduced left ventricle EF, as assessed by echocardiography. Elevated calcium scores and right coronary artery (RCA) stenosis were correlated with a higher risk of AF recurrence (25.38 ± 4.1% vs. 9.76 ± 2.32%, p = 0.001). Patients with AF recurrence presented a higher left atrial volume index (LAVI) (61.38 ± 11.12 mm3/m2 vs. 46.34 ± 12.27 mm3/m2, p < 0.0001). The bi-atrial volume index (BAVI) was similarly higher in the AF recurrence group (98.23 ± 14.44 mm3/m2 vs. 76.48 ± 17.61 mm3/m2, p < 0.0001). Increased EAT volumes located around the LA (EAT-LA) were correlated with recurrence (25.55 ± 6.37 vs. 15.54 ± 8.44, p < 0.0001).

CONCLUSIONS

RCA stenosis, together with atrial volumes and EAT-AS evaluated by CCTA, is associated with the risk of AF recurrence following PVI.

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.

miR-135 protects against atrial fibrillation by suppressing intracellular calcium-mediated NLRP3 inflammasome activation

Atrial fibrillation (AF), one of the most common types of arrhythmias, is associated with high morbidity and mortality, seriously endangering human health. Inflammation is closely associated with AF development. Activation of the nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome in cardiomyocytes has been shown to promote AF progression. Here, we demonstrate the effect of miR-135 on NLRP3 inflammasome and study the cardioprotective role of miR-135 in AF. We observed that overexpression of miR-135 in mice reduced the AF incidence and duration, and inhibited both excessive activation of NLRP3 inflammasome and the increased intracellular calcium release during AF. However, the inhibitory effect of miR-135 on AF was partly abolished in the presence of a specific agonist of the calcium-sensing receptor (CaSR). We showed in the present study that miR-135 has a protective effect against AF by suppressing intracellular calcium-mediated NLRP3 inflammasome activation, suggesting the potential of miR-135 as a therapeutic agent in the treatment of AF.

Reimbursement and use of oral anticoagulants during 2014-2022 - A register-based study

Background

Vitamin K antagonists, warfarin in particular, have been the mainstay of anticoagulation therapy, but their use has declined in many countries since direct oral anticoagulants (DOACs) have entered the market.

Objective

To examine utilization trends of oral anticoagulants (OACs) in Finland considering the reimbursement of DOACs and changes to national treatment guidelines for the treatment of atrial fibrillation (AF).

Methods

Both public, aggregated data on reimbursed OAC dispensations and individual-level data on electronic dispensations during 2014-2022 were applied. Data on electronic dispensations during 2015-2016 were used to study OAC initiations. Data on entitlements to reimbursement for DOACs came from public data.

Results

In 2014, there were almost 20,000 DOAC users, rising to 214,000 in 2022. The number of warfarin users declined since 2015 from over 181,000 to around 59,000 users in 2022, DOACs exceeding warfarin in the number of users in 2019. The total DOAC costs were higher than warfarin costs each year. Rivaroxaban was the most widely used DOAC during 2014-2018, and apixaban during 2019-2022. In 2015, there were more warfarin (56.7%) than DOAC (43.3%) initiators, but the result was opposite for 2016 (warfarin 39.4%, DOACs 60.6%). The number of individuals entitled to reimbursement for DOACs has increased steadily, and in 2022, there were over 196,000 individuals entitled to this reimbursement due to AF.

Conclusions

The uptake of DOACs in Finland appears to have been gradual and slower than in many other countries. During the 2010s, the treatment guidelines for AF were more cautious in recommending DOACs than the European guidelines. The use of DOACs increased as their reimbursement became less restrictive.

Management of Atrial Fibrillation Post Transcatheter Aortic Valve Implantation

Atrial fibrillation (AF) is a common complication in patients who underwent transcatheter aortic valve implantation. Some of these patients have preexisting AF as well. The management of these patients is complex, especially after the procedure, when there is a sudden change in hemodynamics. There are no established guidelines about the management of the patients who underwent transcatheter aortic valve replacement with preexisting or new-onset AF. This review article discusses the management of these patients with rate and rhythm control strategies with medications. This article also highlights the role of newer oral anticoagulation medications and left atrial occlusion devices to prevent stroke after the procedure. We will also discuss new advances in the care of this patient population to prevent the occurrence of AF after transcatheter aortic valve implantation. In conclusion, this article is a synopsis of both pharmacologic and device interventions for the management of AF in patients who underwent transcatheter aortic valve replacement.

Antithrombotic therapy for atrial fibrillation in hereditary hemorrhagic telangiectasia

Antithrombotic therapy reduces stroke risk in patients with atrial fibrillation but at the cost of increased bleeding risk. Patients with hereditary hemorrhagic telangiectasia (HHT) are at increased bleeding risk due to fragile mucocutaneous telangiectasias and visceral arteriovenous malformations. These patients are simultaneously at elevated thrombotic risk due to the vascular abnormalities of HHT. Managing atrial fibrillation in patients with HHT represents an understudied and challenging clinical scenario. We present a retrospective cohort study investigating antithrombotic therapy in patients with HHT and atrial fibrillation. We found that antithrombotic therapy was poorly tolerated, leading to premature dose-reduction or discontinuation of therapy in a majority of patients and in a majority of treatment episodes. Five patients undergoing left atrial appendage procedures did well despite difficulties completing the prescribed course of post-procedure antithrombotic therapy. Left atrial appendage occlusion or simultaneous administration of systemic anti-angiogenic therapy may represent alternatives but require additional study in patients with HHT.

Ischemic stroke risk factors not included in the CHADS-VASC score in patients with non-valvular atrial fibrillation

BACKGROUND

In patients with atrial fibrillation, the CHA2DS2-VASC score guides stroke prevention using anticoagulants, but it is an imperfect score. Other potential risk factors such as renal failure, the type of atrial fibrillation, active smoking, cancer, sleep apnea or systemic inflammation have less well been investigated.

OBJECTIVE

To assess the impact of these factors on ischemic stroke risk in patients with non-valvular atrial fibrillation.

METHODS

On a population of 248 patients (124 patients with acute ischemic stroke and 124 controls), we performed a logistic regression to assess the impact of multiple non-classic risk factors for the prediction of acute ischemic stroke. Their impact on mortality was assessed by performing a survival analysis.

RESULTS

A high CHA2DS2-VASc score (OR 1.75; 95% CI 1.13-2.70; p = 0.032), treatment with anticoagulants (OR 0.19; 95% CI 0.07-0.51; p < 0.001) and permanent atrial fibrillation (OR 6.31; 95% CI 2.46-16.19; p < 0.001) were independently associated with acute ischemic stroke. Renal failure and chronic obstructive pulmonary disease predicted a higher mortality. After adjusting for age, sex, the CHA2DS2-VASc score and the use of anticoagulants, the only risk factor predictive for acute ischemic stroke was the permanent type of AF (OR: 8.0 [95% CI 2.5-25.5], p < 0.001).

CONCLUSIONS

The CHA2DS2-VASc score, the absence of anticoagulants and the permanent type of atrial fibrillation were the main predictive factors for the occurrence of acute ischemic stroke. Larger studies are necessary for conclusive results about other factors.