Pathophysiology of Atrial Fibrillation and Heart Failure

Catheter ablation for atrial fibrillation: indications and future perspective

Recent advances in techniques, technologies and proven superiority over anti-arrhythmic drugs have made catheter ablation the cornerstone of management for atrial fibrillation (AF), which has shown a steady increase in prevalence in the ageing population worldwide. The aim of therapeutic interventions is to achieve stable sinus rhythm that would improve the quality of life and reduce the risk of AF-associated complications. Pulmonary veins (PVs) were first described as the source of initiation of ectopic triggers driving AF, which led to the establishment of PV isolation (PVI) as the most widely practiced procedure to treat AF. Antral PVI is still recognized as the stand-alone ablation strategy for newly diagnosed paroxysmal AF (PAF). However, in non-PAF patients, PVI seems to be inadequate and several adjunctive strategies, including ablation of left atrial posterior wall and non-PV triggers, AF mapping and ablation of rotors and drivers, ethanol infusion of vein of Marshall and renal denervation, etc. have been reported with mixed results. Recent trials have also documented the benefits of early rhythm control in preventing cardiovascular events in addition to slowing the progression of PAF to more persistent forms. Similarly, very late relapse of the arrhythmia after successful PVI has drawn attention to the critical role of non-PV triggers and highlighted their relevance as potential ablation targets during repeat procedures. Ablation technology is also under constant evolution with the introduction of non-thermal energy sources and new tools to create durable lesions. This review summarizes the indications, advancements, and future perspective of AF ablation.

Clinical Update in Heart Failure with Preserved Ejection Fraction

PURPOSE OF REVIEW

To review the most recent clinical trials and data regarding epidemiology, pathophysiology, diagnosis, and treatment of heart failure with preserved ejection fraction with an emphasis on the recent trends in cardiometabolic interventions.

RECENT FINDINGS

Heart failure with preserved ejection fraction makes up approximately half of overall heart failure and is associated with significant morbidity, mortality, and overall burden on the healthcare system. It is a complex, heterogenous syndrome and clinical trials, to this point, have not revealed quite as many effective treatment options when compared to heart failure with reduced ejection fraction. Nevertheless, there is an expanding amount of data insight into the pathogenesis of this disease and the potential for newer therapies and management strategies. Heart failure with preserved ejection fraction pathology has been found to be linked to abnormal energetics, myocyte hypertrophy, cell signaling, inflammation, ischemia, and fibrosis. These mechanisms also intricately overlap with the significant comorbidities often associated with heart failure with preserved ejection fraction including, but not limited to, atrial fibrillation, chronic kidney disease, hypertension, obesity and coronary artery disease. Treatment of this disease, therefore, should focus on the management and strict regulation of these comorbidities by pharmacologic and nonpharmacologic means. In this review, a clinical update is provided reviewing the most recent clinical trials and data regarding epidemiology, pathophysiology, diagnosis, and treatment of heart failure with preserved ejection fraction with an emphasis on the recent trend in cardiometabolic interventions.

All-Cause Mortality of Atrial Fibrillation and Heart Failure in the Same Patient: Does the Order Matter?

INTRODUCTION

Atrial fibrillation (AF) and heart failure (HF) often coexist due to the common elements of the pathomechanism they share. The potential significance of the order these entities present in the same patient is ill-defined. Herein, we report our results from a nationwide database on the occurrence of various sequences AF and HF may present, the time delays between the two conditions and all-cause mortality associated with different scenarios.

METHODS

Patients diagnosed with both AF and HF between 2015 and 2021 were enrolled from the Hungarian National Health Insurance Fund (NHIF) database. The order the two entities followed each other, and the time delay in between were registered. Median survival rates were calculated in AF → HF; HF → AF and simultaneous scenarios.

RESULTS

A total of 109,075 patients were enrolled: 29,937 with AF → HF, 38,171 with HF → AF, and 40,967 diagnosed simultaneously. Time delays between AF → HF and HF → AF were 6 and 10 months, respectively. The median survival was 46 months in the AF → HF, 38 months in the HF → AF, and 21 months in the simultaneous group. Patients with HF → AF, and with simultaneous presentations had 5% and 16% greater mortality risk as compared to the AF → HF sequence, with hazard ratios (95% confidence intervals) of 0.95 (0.93-0.97) and 0.84 (0.82-0.85), respectively (P < 0.0001).

CONCLUSIONS

HF occurred significantly earlier after the diagnosis of AF than vice versa. Patients diagnosed simultaneously had the worst, while the AF → HF sequence had the best prognosis. These data should have implications for the intensification of monitoring and therapy in different scenarios.

Robotic-enhanced hybrid ablation for persistent and long-standing atrial fibrillation: Early assessment of feasibility, safety, and efficacy

Objectives

To assess feasibility, safety, and early efficacy of robotic-enhanced epicardial ablation (RE-EA) as first stage of a hybrid approach to patients with persistent (PsAF) and long-standing atrial fibrillation (LSAF).

Methods

Single-center, retrospective analysis of patients with documented PsAF and LSAF who underwent RE-EA followed by catheter-guided endocardial ablation. Postoperatively, patients were monitored for major adverse events and underwent rhythm follow-up at 3 and 12 months.

Results

Between January 2021 and June 2023, we performed RE-EA in 64 patients (73.5% male, CHA2DS2-VASc 2.7 ± 1.6, BMI 34.1 ± 6.3 kg/m2). Mean AF preoperative duration and left atrial volume index were, respectively, 85 months and 47.5 mL/m2. Through the robotic approach, the intended lesion set was completed in all patients without cardiopulmonary bypass support, conversion to thoracotomy/sternotomy, blood transfusions, or perioperative mortality. The average LOS was 1.7 days, with only 1 patient requiring intensive care unit admission and >65% of patients discharged within 24 hours. At follow-up, 2 (3.1%) patients experienced new left pleural effusion or hemidiaphragm paralysis requiring treatment. There were no readmissions related to AF, stroke, thromboembolic events, or deaths. The mean interval between the epicardial and endocardial stages of the procedure was 5.9 months. Rhythm follow-up showed AF resolution in 73.4% and 71.9% of patients at 3 and 12 months, respectively.

Conclusions

RE-EA is a feasible and safe, first-stage approach for the treatment of patients with PsAF and LSAF. It improves exposure of the intended targets, favors short hospital stay, and facilitates return to activity with satisfactory AF treatment in the short term.

GLP-1 receptor agonists and myocardial metabolism in atrial fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Many medical conditions, including hypertension, diabetes, obesity, sleep apnea, and heart failure (HF), increase the risk for AF. Cardiomyocytes have unique metabolic characteristics to maintain adenosine triphosphate production. Significant changes occur in myocardial metabolism in AF. Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been used to control blood glucose fluctuations and weight in the treatment of type 2 diabetes mellitus (T2DM) and obesity. GLP-1RAs have also been shown to reduce oxidative stress, inflammation, autonomic nervous system modulation, and mitochondrial function. This article reviews the changes in metabolic characteristics in cardiomyocytes in AF. Although the clinical trial outcomes are unsatisfactory, the findings demonstrate that GLP-1 RAs can improve myocardial metabolism in the presence of various risk factors, lowering the incidence of AF.

Evaluation of Clinical, Echocardiographic, and Therapeutic Characteristics, and Prognostic Outcomes of Coexisting Heart Failure among Patients with Atrial Fibrillation: The Jordan Atrial Fibrillation (JoFib) Study

BACKGROUND

Atrial fibrillation (AF) is the most commonly encountered cardiac arrhythmia in clinical practice. Heart failure (HF) can occur concurrently with AF.

AIM

We compared different demographic, clinical, and echocardiographic characteristics between patients with AF+HF and patients with AF only. Furthermore, we explored whether concurrent HF independently predicts several outcomes (all-cause mortality, cardiovascular mortality, ischemic stroke/systemic embolism (IS/SE), major bleeding, and clinically relevant non-major bleeding (CRNMB)).

MATERIALS AND METHODS

Comparisons between the AF+HF and the AF-only group were carried out. Multivariable Cox proportional hazard models were constructed for each outcome to assess whether HF was predictive of any of them while controlling for possible confounding factors.

RESULTS

A total of 2020 patients were included in this study: 481 had AF+HF; 1539 had AF only. AF+HF patients were older, more commonly males, and had a higher prevalence of diabetes mellitus, dyslipidemia, coronary artery disease, and chronic kidney disease (p≤0.05). Furthermore, AF+HF patients more commonly had pulmonary hypertension and low ejection fraction (p≤0.001). Finally, HF was independently predictive of all-cause mortality (adjusted HR 2.17, 95% CI (1.66-2.85) and cardiovascular mortality (adjusted HR 2.37, 95% CI (1.68-3.36).

CONCLUSION

Coexisting AF+HF was associated with a more labile and higher-risk population among Jordanian patients. Furthermore, coexisting HF independently predicted higher all-cause mortality and cardiovascular mortality. Efforts should be made to efficiently identify such cases early and treat them aggressively.

The Optimal Management of Patients with Atrial Fibrillation and Acute Heart Failure in the Emergency Department

Atrial fibrillation (AF) and acute heart failure (AHF) are two closely interrelated conditions that frequently coexist in a manifold manner, with AF serving either as the causative factor or as the consequence or even as an innocent bystander. The interplay between these two clinical conditions is complex, given that they share common pathophysiological pathways and they can reciprocally exacerbate each other, thus triggering a vicious cycle that worsens the prognosis and increases the thromboembolic risk. The optimal management of AF in the context of AHF in the emergency department remains a challenge depending on the time onset, as well as the nature and the severity of the associated symptoms. Acute rate control, along with early rhythm control, when indicated, and anticoagulation represent the main pillars of the therapeutic intervention. The purpose of this review is to elucidate the pathophysiological link between AF and AHF and accordingly present a stepwise algorithmic approach for the management of AF in AHF patients in the emergency setting.

Prevalence of Heart Failure With Preserved Ejection Fraction in Patients Undergoing Atrial Fibrillation Ablation Based on Resting and Post-Tachycardia Pacing Left Atrial Pressure

Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) are frequent co-morbid conditions. In patients with symptomatic AF and preserved left ventricular ejection fraction the clinical diagnosis of HFpEF may be difficult, as history, examination, and echocardiography are not sensitive or specific. This study sought to assess the prevalence of HFpEF in patients undergoing AF ablation utilizing resting and post-tachycardia pacing left atrial pressure (LAP) measurements. This retrospective cohort study consisted of consecutive patients with symptomatic AF and preserved left ventricular ejection fraction who had invasive hemodynamic assessment (IHA) of LAP under resting and post-tachycardia pacing conditions while undergoing AF ablation from 2020 to 2022 at a tertiary care academic medical center. Elevated LAP was defined as ≥15 mm Hg at rest and ≥15 mm Hg post-tachycardia pacing. Patients were stratified into 3 groups: (1) normal resting and post-tachycardia pacing LAP (control group), (2) elevated resting LAP (apparent HFpEF), (3) normal resting but elevated post-tachycardia pacing LAP (occult HFpEF). A total of 78 patients were included with age 64.6 ± 9.1 years, 28 (36%) female, body mass index 33.3 ± 6.5 kg/m2, 5 (6%) paroxysmal and 73 (94%) persistent AF, and CHA2DS2-VASc 3.0 ± 1.5. IHA categorized 31 (40%), 32 (41%), and 15 patients (19%) into groups 1, 2, and 3 respectively. Notably, while only 9 patients (12%) were diagnosed with HFpEF based on clinical evaluation, 47 patients (60%) were diagnosed by IHA. IHA in patients undergoing AF ablation suggests a high prevalence of clinically undiagnosed HFpEF through a novel methodology measuring resting and post-tachycardia pacing LAP.

A Correlative Relationship Between Heart Failure and Cognitive Impairment: A Narrative Review

Heart failure (HF) is a chronic condition affecting millions of people worldwide. While the cardinal manifestations of HF are related to the cardiovascular system, it has become progressively evident that mild cognitive impairment (MCI) is also a significant complication of the disease. In fact, a significant number of patients with HF may experience MCI, which can manifest as deficits in attention, memory, executive function, and processing speed. The mechanisms responsible for cognitive dysfunction in HF are intricate and multifactorial. Possible factors contributing to this condition include decreased cerebral blood flow, thrombogenicity associated with HF, systemic inflammatory conditions, and proteotoxicity. MCI in HF has significant clinical implications, as it is linked to poorer quality of life, increased morbidity and mortality, and higher healthcare costs. Additionally, MCI can disrupt self-care behaviors, adherence to medication, and decision-making abilities, all of which are crucial for effectively managing HF. However, there is currently no gold standard diagnostic tool and follow-up strategy for MCI in HF patients. There is limited knowledge on the prevention and treatment of MCI. In conclusion, MCI is a common and clinically important complication of HF. Considering the substantial influence of MCI on patient outcomes, it is imperative for healthcare providers to be cognizant of this issue and integrate cognitive screening and management strategies into the care of HF patients.

Heart failure outcomes in low-risk patients with atrial fibrillation: a case-control study of 680 523 Swedish individuals

AIMS

Knowledge of long-term outcomes in patients with atrial fibrillation (AF) remains limited. We sought to evaluate the risk of new-onset heart failure (HF) in patients with AF and a low cardiovascular risk profile.

METHODS AND RESULTS

Data from the Swedish National Patient Register were used to identify all patients with a first-time diagnosis of AF without underlying cardiovascular disease at baseline between 1987 and 2018. Each patient was compared with two controls without AF from the National Total Population Register. In total, 227 811 patients and 452 712 controls were included. During a mean follow-up of 9.1 (standard deviation 7.0) years, the hazard ratio (HR) for new-onset HF was 3.55 [95% confidence interval (CI) 3.51-3.60] in patients compared with controls. Women with AF (18-34 years) had HR for HF onset 24.6 (95% CI 7.59-80.0) and men HR 9.86 (95% CI 6.81-14.27). The highest risk was within 1 year in patients 18-34 years, HR 103.9 (95% CI 46.3-233.1). The incidence rate within 1 year increased from 6.2 (95% CI 4.5-8.6) per 1000 person-years in young patients (18-34 years) to 142.8 (95% CI 139.4-146.3) per 1000 person-years among older patients (>80 years).

CONCLUSIONS

Patients studied had a three-fold higher risk of developing HF compared with controls. Young patients, particularly women, carry up to 100-fold increased risk to develop HF within 1 year after AF. Further studies in patients with AF and low cardiovascular risk profile are needed to prevent serious complications such as HF.

Global historical retrospect and future prospects on biomarkers of heart failure: A bibliometric analysis and science mapping

Introduction

Heart failure is a rapidly growing public health problem and has become a major cause of hospitalization in middle-aged and older adults. Biomarkers are clinically important in managing heart failure and have attracted more attention from researchers in recent years. This study aimed to evaluate the global research of heart failure biomarkers by bibliometrics and to identify the hot spots and perspectives for further advancement.

Methods

Selection of relevant documents was from the Web of Science Core Collection. Microsoft Excel, VOSviewer, SciMA, and CiteSpace software were used for bibliometric analysis.

Results

As of October 29, 2021, 5,978 documents for heart failure biomarkers have been identified from 1989 to 2021. European Journal of Heart Failure and Circulation respectively ranked first in terms of the number of publications and the number of co-citations. A total of 5,698 institutions from 90 countries participated in these publications, with the USA leading with 2,045 documents. The most productive institution was Harvard University. Januzzi, J.L. and Maisel, A.S. were the most productive and most cited authors respectively. Natriuretic peptide, copeptin, valsartan, ferric carboxymaltose, empagliflozin, preserved ejection fraction, myocardial fibrosis, and heart transplantation were hot themes.

Conclusions

Extensive national and inter-institutional collaboration should be enhanced to bridge the gap between developed and less developed countries in heart failure biomarkers research. The research in this field seems to have reached a relatively mature stage, with a decrease in research fervor in recent years. The study of the natriuretic peptide family still has high centrality, with advances in the study of expression products and inflammatory markers. Cardiac fibrosis, cardiac remodeling, and therapies regarding heart failure have become hot spots.

Risk of heart failure in elderly patients with atrial fibrillation and diabetes taking different oral anticoagulants: a nationwide cohort study

BACKGROUND

Heart failure (HF) is a critical complication in elderly patients with atrial fibrillation (AF) and diabetes mellitus (DM). Recent preclinical studies suggested that non-vitamin K antagonist oral anticoagulants (NOACs) can potentially suppress the progression of cardiac fibrosis and ischemic cardiomyopathy. Whether different oral anticoagulants influence the risk of HF in older adults with AF and DM is unknown. This study aimed to evaluate the risk of HF in elderly patients with AF and DM who were administered NOACs or warfarin.

METHODS

A nationwide retrospective cohort study was conducted based on claims data from the entire Taiwanese population. Target trial emulation design was applied to strengthen causal inference using observational data. Patients aged  ≥ 65 years with AF and DM on NOAC or warfarin treatment between 2012 and 2019 were included and followed up until 2020. The primary outcome was newly diagnosed HF. Propensity score-based fine stratification weightings were used to balance patient characteristics between NOAC and warfarin groups. Hazard ratios (HRs) were estimated using Cox proportional hazard models.

RESULTS

The study included a total of 24,835 individuals (19,710 NOAC and 5,125 warfarin users). Patients taking NOACs had a significantly lower risk of HF than those taking warfarin (HR = 0.80, 95% CI 0.74-0.86, p < 0.001). Subgroup analyses for individual NOACs suggested that dabigatran (HR = 0.86, 95% CI 0.80-0.93, p < 0.001), rivaroxaban (HR = 0.80, 95% CI 0.74-0.86, p < 0.001), apixaban (HR = 0.78, 95% CI 0.68-0.90, p < 0.001), and edoxaban (HR = 0.72, 95% CI 0.60-0.86, p < 0.001) were associated with lower risks of HF than warfarin. The findings were consistent regardless of age and sex subgroups and were more prominent in those with high medication possession ratios. Several sensitivity analyses further supported the robustness of our findings.

CONCLUSIONS

This nationwide cohort study demonstrated that elderly patients with AF and DM taking NOACs had a lower risk of incident HF than those taking warfarin. Our findings suggested that NOACs may be the preferred oral anticoagulant treatment when considering the prevention of heart failure in this vulnerable population. Future research is warranted to elucidate causation and investigate the underlying mechanisms.

Comparison of radiofrequency ablation and antiarrhythmic drug for the treatment of atrial fibrillation: A protocol for systematic review and meta-analysis

BACKGROUND

Antiarrhythmic drugs and radiofrequency ablation are first-line treatments of atrial fibrillation, however, there exists a paucity of data regarding the potential benefit of different catheter ablation technologies versus antiarrhythmic drugs as an early rhythm strategy. We performed a protocol for systematic review and meta-analysis to compare the efficacy and safety of radiofrequency ablation and antiarrhythmic drugs for the treatment of atrial fibrillation.

METHODS

This review protocol is registered in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42022375095). Additionally, this review will adhere to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols 2015 Statement. A computerized literature search will be performed in the following electronic databases from their inceptions to November 2022: PubMed, EMBASE, MEDLINE, Cochrane Central Register of Controlled Clinical Trials, China Knowledge Resource Integrated Database, Wanfang Data Information, and Weipu Database for Chinese Technical Periodicals. The risk of bias will be assessed independently by 2 authors using the Cochrane tool of risk of bias. All statistical analyses will be conducted using the software program Review Manager version 5.3.

RESULTS

The results of this systematic review will be published in a peer-reviewed journal.

CONCLUSION

This study provides evidence of the comparison of radiofrequency ablation and antiarrhythmic drugs for the treatment of atrial fibrillation.

Incidence and Determinants of Spontaneous Cardioversion of Early Onset Symptomatic Atrial Fibrillation

Atrial fibrillation (AF) is the most frequent chronic arrhythmia worldwide, and it is associated with significant morbidity and mortality, making it a considerable burden both to patients and the healthcare system. Nowadays, an early attempt to restore sinus rhythm in acute symptomatic AF through electrical or pharmacological cardioversion is the most common approach in the Emergency Department (ED). However, considering the high percentage of spontaneous cardioversion of paroxysmal AF reported by many studies, this approach may not be the ideal choice for all patients. In this manuscript we performed a review of the most relevant studies found in literature with the aim of identifying the main determinants of spontaneous cardioversion, focusing on those easy to detect in the ED. We have found that the most relevant predictors of spontaneous cardioversion are the absence of Heart Failure (HF), a small atrial size, recent-onset AF, rapid Atrial Fibrillatory Rate and the relationship between a previous AF episode and Heart Rate/Blood Pressure. A number of those are utilized, along with other easily determined parameters, in the recently developed "ReSinus" score which predicts the likelihood of AF spontaneous cardioversion. Such identification may help the physician decide whether immediate cardioversion is necessary, or whether to adopt a "watch-and-wait" strategy in the presence of spontaneous cardioversion determinants.

Mitral Annular Plane Systolic Excursion (MAPSE) as a Predictor of Atrial Fibrillation Recurrence in Patients after Pulmonary Vein Isolation

Introduction

Catheter ablation (CA) with pulmonary vein isolation (PVI) has become widely used in the past years for the treatment of atrial fibrillation (AF). Mitral annular plane systolic excursion (MAPSE) is the parameter that measures left ventricular longitudinal function, and it appears to be a good early marker of LV dysfunction. It is practically independent of poor image quality. The aim of our study was to analyse the role of echocardiographic variables, especially MAPSE in predicting the outcome of CA in patients with AF.

Materials and Methods

We prospectively included 40 patients with paroxysmal and persistent AF that were referred for CA. All patients underwent radiofrequency CA with PVI. Standard transthoracic two-dimensional echocardiography was conducted one day after CA. Demographic data and the patients' characteristics were noted. The endpoint of our study was to estimate the AF recurrence rate diagnosed by ECG within 6 months of the follow-up period.

Results

40 patients, mainly male (67.5%) with an average age of 61.43 ± 8.96 years were included in our study. The majority of patients had paroxysmal AF prior to ablation (77.5%). The AF recurrence rate was 20% after 6 months of follow-up. Lateral MAPSE in the AF-free group was greater than those who relapsed (1.57 ± 0.24 vs. 1.31 ± 0.25; p = 0.012). Patients who remained AF-free after a 6-month follow-up period had a significantly smaller left ventricular volume index (LAVI) than those who relapsed (34.29 ± 6.91 ml/m² vs. 42.90 ± 8.43 ml/m²; p = 0.05). We found a significant reverse relationship between LAVI and MAPSE (p = 0.020).

Conclusion

MAPSE and LAVI present risk factors for AF recurrence, specifically reduced MAPSE and larger LAVI, are related to AF recurrence after CA. In the future, MAPSE could play a significant role when predicting the CA outcome in patients with AF.

Atrial fibrillation-induced tachycardiomyopathy and heart failure: an underappreciated and elusive condition

Many patients with persistent, chronic, or frequently recurring paroxysmal atrial fibrillation (AF) may develop a tachycardiomyopathy (TCM) with left ventricular (LV) dysfunction and heart failure (HF), which is reversible upon restoration and maintenance of sinus rhythm, when feasible, or via better and tighter ventricular rate (VR) control. Mechanisms involved in producing this leading cause of TCM (AF-TCM) include loss of atrial contraction, irregular heart rate, fast VR, neurohumoral activation, and structural myocardial changes. The most important of all mechanisms relates to optimal VR control, which seems to be an elusive target. Uncontrolled AF may also worsen preexisting LV dysfunction and exacerbate HF symptoms. Data, albeit less robust, also point to deleterious effects of slow VRs on LV function. Thus, a J-shaped relationship between VR and clinical outcome has been suggested, with the optimal VR control hovering at ~ 65 bpm, ranging between 60 and 80 bpm; VRs above and below this range may confer higher morbidity and mortality rates. A convergence of recent guidelines is noted towards a stricter rather than a more lenient VR control with target heart rate < 80 bpm at rest and < 110 bpm during moderate exercise which seems to prevent TCM or improve LV function and exercise capacity and relieve TCM-related symptoms and signs. Of course, restoring and maintaining sinus rhythm is always a most desirable target, when feasible, either with drugs or more likely with ablation. All these issues are herein reviewed, current guidelines are discussed and relevant data are tabulated and pictorially illustrated.

Obstructive Sleep Apnea and Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia, increasing with age and comorbidities. Obstructive sleep apnea (OSA) is a chronic sleep disorder more common in older men. It has been shown that OSA is linked to AF. Nonetheless, the prevalence of OSA in patients with AF remains unknown because OSA is significantly underdiagnosed. This review, including 54,271 patients, carried out a meta-analysis to investigate the association between OSA and AF. We also performed a meta-regression to explore cofactors influencing this correlation. A strong link was found between these two disorders. The incidence of AF is 88% higher in patients with OSA. Age and hypertension independently strengthened this association, indicating that OSA treatment could help reduce AF recurrence. Further research is needed to confirm these findings. Atrial Fibrillation (AF) is the most common arrhythmia, increasing with age and comorbidities. Obstructive sleep apnea (OSA) is a regulatory respiratory disorder of partial or complete collapse of the upper airways during sleep leading to recurrent pauses in breathing. OSA is more common in older men. Evidence exists that OSA is linked to AF. Nonetheless, the prevalence of OSA in patients with AF remains unknown because OSA is underdiagnosed. In order to investigate the incidence of AF in OSA patients, we carried out a meta-analysis including 20 scientific studies with a total of 54,271 subjects. AF was present in 4801 patients of whom 2203 (45.9%) had OSA and 2598 (54.1%) did not. Of a total of 21,074 patients with OSA, 2203 (10.5%) had AF and 18,871 (89.5%) did not. The incidence of AF was 88% higher in patients with OSA. We performed a meta-regression to explore interacting factors potentially influencing the occurrence of AF in OSA. Older age and hypertension independently strengthened this association. The clinical significance of our results is that patients with OSA should be referred early to the cardiologist. Further research is needed for the definition of the mechanisms of association between AF and OSA.

Is Progression From Paroxysmal to Sustained Atrial Fibrillation Bad News?

Atrial fibrillation (AF) is the most common sustained arrhythmia and associated with increased morbidity and mortality resulting from thromboembolism and heart failure. AF often presents initially as paroxysmal and may progress to a sustained form over time. Sustained forms of AF may be associated with increased symptoms and cardiovascular morbidity, and AF progression may be associated with increased risk of clinically adverse events and outcomes. The present review discusses the clinical factors of arrhythmia progression and risk stratification available to assess the probability of AF progression. Furthermore, currently available treatment options for preventing AF progression are explored and evaluated.

The Association of Thyroid Hormones with Cardiogenic Shock and Prognosis in Patients with ST Segment Elevation Myocardial Infarction (STEMI) Treated with Primary PCI

BACKGROUND

Cardiogenic shock (CS) is the leading cause of the death in patients with ST elevation myocardial infarction (STEMI). Thyroid dysfunction is related to prognosis of patients with myocardial infarction. Hence, the aim of this study is to explore the relationship between thyroid hormones (free triiodothyronine [FT3] and free thyroxine [FT4]) and CS.

METHOD

A total of 1270 patients with STEMI treated with percutaneous coronary intervention (PCI) were consecutively enrolled in our study. Patients were classified into two groups according to with or without CS during hospitalization. Stepwise multivariate logistic analysis was conducted to investigate the association of thyroid hormones and CS. Restricted cubic spline method was employed to further explore relationship between CS and thyroid hormones.

RESULTS

Patients who developed CS (n=103) had lower FT3 and higher FT4 on admission. The stepwise logistic analysis showed both FT3 (P=0.038) and FT4 (P=0.024) were independently related to CS. Restricted cubic splines indicated that lower FT3 (<2.25 pg/ml) or higher FT4 (>1.25 ng/dl) was correlated with higher prevalence of CS. Over 2.5 years' follow-up, patients (n=294) with low FT3 (<2.85 pg/ml) and high FT4 (>=0.88 ng/dl) had the highest all-cause mortality (18.2%), whereas patients (n=293) with high FT3 and low FT4 had the lowest all-cause mortality (3.8%) (P for trend <0.0001).

CONCLUSIONS

Both FT3 and FT4 are independently associated with in-hospital CS development in patients with STEMI treated with PCI. Patients with lower range of FT3 and upper range of FT4 had the worst outcomes in a long-term follow-up.

Association of heart failure subtypes and atrial fibrillation: Data from the Atherosclerosis Risk in Communities (ARIC) study

AIMS

To determine the prevalence and incidence of AF among HF subtypes in a biracial community-based cohort.

METHODS

We studied 6496 participants in the Atherosclerosis Risk in Community study (mean age, 75.8 ± 5.3, 59% women, 23% black) who attended the 2011-2013 visit. HF was identified from physician adjudicated diagnosis, hospital discharges, and self-report. HF subtypes were based on echocardiography. A left ventricular ejection fraction <40% represents HF with reduced ejection fraction (HFrEF), 40%-49% for HF with midrange ejection fraction (HFmEF), and ≥ 50% for HF with preserved ejection fraction (HFpEF). AF was ascertained through 2017 from study electrocardiograms, hospital discharges, and death certificates. Confounder-adjusted logistic regression and Cox models were used to estimate associations of HF subtype with prevalent and incident AF.

RESULTS

Among eligible participants, 393 had HF (HFpEF = 232, HFmEF = 41, HFrEF = 35 and unclassified HF = 85) and 735 had AF. Compared to those without HF, all HF subtypes were more likely to have prevalent AF [odds ratio (95% confidence interval (CI)) 7.4 (5.6-9.9) for HFpEF, 8.1 (4.3-15.3) for HFmEF, 10.0 (5.0-20.2) for HFrEF, 8.8 (5.6-14.0) for unclassified HF]. Among participants without AF at baseline (n = 5761), 610 of them developed AF. Prevalent HF was associated with increased risk of AF [hazard ratio (95%CI) 2.3 (1.6-3.2) for HFpEF, 5.0 (2.7-9.3) for HFmEF, 3.5 (1.7-7.6) for HFrEF, 1.9 (0.9-3.7) for unclassified HF].

CONCLUSION

AF and HF frequently co-occur, with small differences by HF subtype, underscoring the importance of understanding the interplay of these two epidemics and evaluating shared preventive and therapeutic strategies.

Human Atrial Fibrillation Is Not Associated With Remodeling of Ryanodine Receptor Clusters

The release of Ca²⁺ by ryanodine receptor (RyR2) channels is critical for cardiac function. However, abnormal RyR2 activity has been linked to the development of arrhythmias, including increased spontaneous Ca²⁺ release in human atrial fibrillation (AF). Clustering properties of RyR2 have been suggested to alter the activity of the channel, with remodeling of RyR2 clusters identified in pre-clinical models of AF and heart failure. Whether such remodeling occurs in human cardiac disease remains unclear. This study aimed to investigate the nanoscale organization of RyR2 clusters in AF patients – the first known study to examine this potential remodeling in diseased human cardiomyocytes. Right atrial appendage from cardiac surgery patients with paroxysmal or persistent AF, or without AF (non-AF) were examined using super-resolution (dSTORM) imaging. Significant atrial dilation and cardiomyocyte hypertrophy was observed in persistent AF patients compared to non-AF, with these two parameters significantly correlated. Interestingly, the clustering properties of RyR2 were remarkably unaltered in the AF patients. No significant differences were identified in cluster size (mean ∼18 RyR2 channels), density or channel packing within clusters between patient groups. The spatial organization of clusters throughout the cardiomyocyte was also unchanged across the groups. RyR2 clustering properties did not significantly correlate with patient characteristics. In this first study to examine nanoscale RyR2 organization in human cardiac disease, these findings indicate that RyR2 cluster remodeling is not an underlying mechanism contributing to altered channel function and subsequent arrhythmogenesis in human AF.

Risk Factors for Atrial Fibrillation Progression

Atrial fibrillation is a chronic, progressive condition that presents a major health burden. This review summarizes recent studies assessing atrial fibrillation progression and its associated risk factors, describes the mechanisms underlying atrial fibrillation progression, and discusses the clinical implications of the progressive nature of atrial fibrillation. Progression of atrial fibrillation burden, and clinical progression from paroxysmal to more advanced (persistent/permanent) forms is common, but progression rates are variable. Atrial fibrillation progression parallels progressive atrial remodeling induced by atrial fibrillation risk factors and atrial fibrillation itself, and is associated with worse clinical outcomes.

A novel age-biomarker-clinical history prognostic index for heart failure with reduced left ventricular ejection fraction

Purpose

A model for predicting the prognosis of patients with heart failure with reduced left ventricular ejection fraction (HFrEF) is currently not available. This study aimed to develop an age-biomarker-clinical history prognostic index (ABC-PI) and validate it for the assessment of individual prognosis.

Patients and methods

A total of 5,974 HFrEF patients were enrolled and 1,529 were included in this study after excluding missing values and loss to follow-up. Variables that significantly contributed to prediction of all-cause mortality were assessed by Cox regression and latent trait analysis (LTA) was used to validate discrimination of variables.

Results

After Cox regression, the following seven most significant variables were selected: age, N-terminal pro-B-type natriuretic peptide, renal dysfunction, left ventricular mass index, percutaneous coronary intervention, atrial fibrillation, and New York Heart Association (C-index: 0.801 ± 0.013). After verification by LTA, discrimination of these seven variables was proven. A nomogram was used to form the ABC-PI, and then the total score was set to 100 points. A lower score indicated a higher risk. After verification, the 3-year mortality rate was 34.7% in the high-risk group and only 2.6% in the low-risk group.

Conclusion

Our novel ABC-PI shows a good performance and does not require re-input in the original model. The ABC-PI can be used to effectively and practically predict the prognosis of HFrEF patients.

Dynamics of Atrial Fibrillation Mechanisms and Comorbidities

Atrial fibrillation (AF) contributes to morbidity and mortality of millions of individuals. Its molecular, cellular, neurohumoral, and hemodynamic pathophysiological mechanisms are complex, and there is increasing awareness that a wide range of comorbidities can contribute to AF-promoting atrial remodeling. Moreover, recent research has highlighted that AF risk is not constant and that the temporal variation in concomitant conditions contributes to the complexity of AF dynamics. In this review, we provide an overview of fundamental AF mechanisms related to established and emerging comorbidities or risk factors and their role in the AF-promoting effects. We focus on the accumulating evidence for the relevance of temporally dynamic changes in these risk factors and the consequence for AF initiation and maintenance. Finally, we highlight the important implications for future research and clinical practice resulting from the dynamic interaction between AF risk factors and mechanisms.

Heart failure with preserved ejection fraction or non-cardiac dyspnea in paroxysmal atrial fibrillation: The role of left atrial strain

BACKGROUND

Diagnosis of heart failure with preserved ejection fraction (HFpEF) in patients with dyspnea and paroxysmal atrial fibrillation (AF) is challenging. Speckle tracking-derived left atrial strain (LAS) provides an accurate estimate of left ventricular (LV) filling pressures and left atrial (LA) phasic function. However, data on clinical utility of LAS in patients with dyspnea and AF are scarce.

OBJECTIVE

To assess relationship between the LAS and the probability of HFpEF in patients with dyspnea and paroxysmal AF.

METHODS

The study included 205 consecutive patients (62 ± 10 years, 58% males) with dyspnea (NYHA≥II), paroxysmal AF and preserved LV ejection fraction (≥50%), who underwent speckle tracking echocardiography during sinus rhythm. Probability of HFpEF was estimated using H₂FPEF and HFA-PEFF scores, which combine clinical characteristics, echocardiographic parameters and natriuretic peptides.

RESULTS

Patients with high probability of HFpEF were significantly older, had higher body mass index, NT-proBNP, E/e', pulmonary artery pressure and larger LA volume index than patients in low-to-intermediate probability groups (all p < 0.05). All components of LAS and LA strain rate showed proportional impairment with increasing probability of HFpEF (all p < 0.05). Out of the speckle tracking-derived parameters, reservoir LAS showed the largest area under the curve (AUC = 0.78, p < 0.001) and the strongest independent predictive value (OR: 1.22, 95% CI 1.08-1.38) to identify patients with high probability of HFpEF.

CONCLUSIONS

Reservoir LAS shows a high diagnostic performance to distinguish HFpEF from non-cardiac causes of dyspnea in symptomatic patients with paroxysmal AF.

Efficacy and safety of non-vitamin K anticoagulants and warfarin in patients with atrial fibrillation and heart failure: A network meta-analysis

BACKGROUND

To recommend the proper anticoagulant drug and its dose for patients with atrial fibrillation (AF) and heart failure (HF), we conducted a network meta-analysis (NMA) to make the comparisons among non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin with regard to efficacy (stroke or systemic embolism) and safety (major bleeding).

METHODS

We searched PubMed, EMBASE, Web of Science and Cochrane Library with the items: "dabigatran, edoxaban, apixaban, rivaroxaban, warfarin, atrial fibrillation and heart failure" through April 14, 2020, focusing on the RCTs comparing the effect of NOACs to warfarin in patients with AF and HF. The NMA was performed based on R (version3.5.1) recalling JAGS (version4.3.0) with gemtc package. Moreover, NetMetaXL (version1.6.1) and winBUGS (version1.4.3) were employed to obtain the cumulative ranking curve area (SUCRA) of the anticoagulants.

RESULT

There was a high probability that dabigatran150 (SUCRA 0.82) ranked the first for the most effective drug, followed by apixaban (SUCRA 0.81), edoxaban60 (SUCRA 0.57) and rivaroxaban (SUCRA 0.52). However, with respect to safety for preventing major bleeding, edoxaban30 (SUCRA 0.99) ranked as the safest drug, followed by apixaban (SUCRA 0.71), edoxaban 60 (SUCRA 0.59) and dabigatran150 (SUCRA 0.55).

CONCLUSION

Apixaban, edoxaban60 and dabigatran150 were more likely to become the choice for preventing stroke or systemic embolism and major bleeding in patients with AF and HF. Nevertheless, more trials need to be performed to focus on the effect of NOACs on the efficacy outcome due to the sparse data. In addition, caution should be excised over selecting the NOAC and its dose on account of the lacking head-to-head comparisons.

Hemodynamic profile of patients with severe aortic valve stenosis and atrial fibrillation versus sinus rhythm

BACKGROUND

In patients with severe aortic stenosis (AS), atrial fibrillation (AF) is associated with increased long-term mortality after aortic valve replacement (AVR), which may be due to unfavorable hemodynamics in AF. We aimed to analyze the hemodynamic profile of patients with severe AS and AF versus sinus rhythm (SR).

METHODS

We performed cardiac catheterization in 486 patients (age 74 ± 10 years, 58% males) with severe AS [indexed aortic valve area 0.41 ± 0.13 cm², left ventricular ejection fraction 58 ± 12%]: 50 patients had AF, and 436 patients had SR. All patients underwent surgical (n = 350) or transcatheter (n = 136) AVR.

RESULTS

Despite similar indexed aortic valve area (0.41 ± 0.11 vs. 0.41 ± 0.12 cm²/m²; p = 0.45) patients with AF had lower left ventricular ejection fraction, larger left atrial size, lower tricuspid annular plane systolic excursion, higher mean pulmonary artery pressure (34 ± 13 vs. 24 ± 9 mmHg), mean pulmonary artery wedge pressure (mPAWP; 22 ± 8 vs. 15 ± 7 mmHg), and pulmonary vascular resistance (2.8 ± 1.9 vs. 2.0 ± 1.3 Wood units) and lower stroke volume index (26 ± 9 vs. 37 ± 10 ml/m²) than patients with SR (p < 0.05 for all). Patients with AF and SR had a different mPAWP-left ventricular end-diastolic pressure (LVEDP) relationship with higher mPAWP in AF and higher LVEDP in SR. After a median follow-up of 49 (interquartile range, 35-64) months post-AVR patients with AF (p = 0.05) and patients with a larger difference between mPAWP and LVEDP (p = 0.005) had higher mortality.

CONCLUSIONS

Patients with severe AS and concomitant AF have a distinct and significantly worse hemodynamic profile compared to patients with SR associated with worse clinical outcome.

Arrhythmia recurrence is more common in females undergoing multiple catheter ablation procedures for persistent atrial fibrillation: Time to close the gender gap

BACKGROUND

Female gender is associated with an increased recurrence of atrial fibrillation (AF) after catheter ablation (CA). Although AF is more common in men, women constitute a significant proportion with persistent atrial fibrillation (PsAF).

OBJECTIVE

The purpose of this study was to determine whether multiple ablation procedures improves arrhythmia outcomes in females with PsAF compared to men.

METHODS

We performed a multicenter observational study to determine long-term arrhythmia outcomes in patients undergoing >1 CA for PsAF. CA involved pulmonary vein (PV) isolation with additional ablation including linear, posterior wall isolation, electrogram-guided, or a combination of these.

RESULTS

A total of 281 patients had >1 ablation procedure for PsAF and were included in this analysis (mean age 58.7 ± 9.3 years; 86 [30.6%] female; left atrial [LA] area 27.0 ± 5.3 cm²; PsAF duration 1.7 ± 1.7 years). At mean follow-up of 45.5 ± 31.8 months, freedom from recurrent AF was present in 148 patients(52.7%) after 2.2 ± 0.5 procedures. After multivariate analysis, female gender (hazard ratio [HR] 2.10; P <.001) and enduring PV isolation (HR 1.64; P = .01) were independently associated with AF recurrence. Enduring PV isolation was significantly higher in women than in men (33.7% vs 19.5%; P = .01).

CONCLUSION

Female gender was independently and strongly associated with arrhythmia recurrence in patients undergoing multiple procedures for PsAF. PV reconnection was less likely, and fewer reconnected PVs occurred in women. Further studies are required to better understand the mechanisms responsible for AF in females to assist in closing the gender gap in the success of CA.