Sudden Cardiac Death in Patients With Atrial Fibrillation: Insights From the ENGAGE AF-TIMI 48 Trial

Aged gut microbiota promotes arrhythmia susceptibility via oxidative stress

Arrhythmias and sudden cardiac death (SCD) impose a significant burden. Their prevalence rises with age and is linked to gut dysbiosis. Our study aimed to determine whether aged gut microbiota affects arrhythmogenesis. Here, we demonstrated that arrhythmia susceptibility in aged mice could be transmitted to young mice using fecal microbiota transplantation (FMT). Mechanistically, increased intestinal reactive oxygen species (ROS) in aged mice reduced ion channel protein expression and promoted arrhythmias. Gut microbiota depletion by an antibiotic cocktail reduced ROS and arrhythmia in aged mice. Interestingly, oxidative stress in heart induced by hydrogen peroxide (H2O2) increased arrhythmia. Moreover, aged gut microbiota could induce oxidative stress in young mice colon by gut microbiota metabolites transplantation. Vitexin could reduce aging and arrhythmia through OLA1-Nrf2 signaling pathway. Overall, our study demonstrated that the gut microbiota of aged mice reduced cardiac ion channel protein expression through systemic oxidative stress, thereby increased the risk of arrhythmias.

Impact of atrial fibrillation on pulmonary embolism hospitalization: Nationwide analysis

Introduction

Atrial fibrillation (AF) is the most common type of arrythmia affecting approximately 1-2 % of the adult population. Patients with an underlying history of atrial fibrillation have a greater chance of developing venous thromboembolism (VTE). Likewise, patients with VTE are at increased risk for AF. There has been conflicting evidence on the prognostic impact of AF in acute pulmonary embolism (PE) patients. The aim of this retrospective cohort study was to estimate the impact of AF on the clinical outcomes of hospitalization for PE.

Method

The 2016-2021 National Inpatient Sample database was searched for adult patients hospitalized with PE with associated history of AF as the principal discharge diagnosis. The primary outcome was inpatient mortality, while the secondary outcomes were length of stay (LOS), total hospital charge (THC), cardiogenic shock, acute respiratory failure, in-hospital cardiac arrest (IHCA). The outcomes were analyzed using multivariable logistic and linear regression analyses.

Results

A total of 1,128,269 patients were admitted for PE, 12.4 % of whom had underlying AF. The AF and non-AF cohorts had a mean age of 73.6 years and 61.6 years, respectively. PE patient with AF had significantly higher mortality compared to non-AF patients with PE (6.05 % vs 2.75 %, adjusted odds ratio of 1.67 [95 % CI 1.56-1.79; p < 0.0001]). The PE with AF cohort had increased odds of cardiac arrest, cardiogenic shock, respiratory failure requiring intubation, higher average length of stay (5.66 days vs 4.18 days, P < 0.001) and a higher total hospital cost (65,235 vs 50,118, P < 0.001).

Conclusion

AF was associated with increased inpatient mortality and worse clinical outcomes in hospitalization for acute PE.

Predictors of ventricular tachyarrhythmia in patients with a wearable cardioverter defibrillator: an international multicenter registry

BACKGROUND AND AIMS

Wearable cardioverter defibrillator (WCD) can protect patients from sudden cardiac death due to ventricular tachyarrhythmias and serve as a bridge to decision of definite defibrillator implantation. The aim of this analysis from an international, multicenter WCD registry was to identify predictors of sustained ventricular tachycardia (VT) and/or ventricular fibrillation (VF) in this population.

METHODS

One thousand six hundred seventy-five patients with WCD were included in a multicenter registry from 9 European centers, with a median follow-up of 440 days (IQR 120-893). The primary study end point was the occurrence of sustained VT/VF.

RESULTS

Sustained VT was detected by WCD in 5.4% and VF in 0.9% of all patients. Of the 30.3% of patients receiving ICD implantation during follow-up, sustained VT was recorded in 9.3% and VF in 2.6%. Non-ischemic cardiomyopathy (HR 0.5, p < 0.001), and medication with angiotensin-converting enzyme inhibitors (HR 0.7, p = 0.027) and aldosterone antagonists (HR 0.7, p = 0.005) were associated with a significantly lower risk of VT/VF.

CONCLUSIONS

Patients who received WCD due to a transient increased risk of sudden cardiac death have a comparatively lower risk of VT/VF in the presence of non-ischemic cardiomyopathy. Of note, optimal medical treatment for heart failure not only results in an improvement in left ventricular ejection fraction but also in a reduction in the risk for VT/VF.

Causes of death in patients with atrial fibrillation anticoagulated with rivaroxaban: a pooled analysis of XANTUS

AIMS

Anticoagulation can prevent stroke and prolong lives in patients with atrial fibrillation (AF). However, anticoagulated patients with AF remain at risk of death. The aim of this study was to investigate the causes of death and factors associated with all-cause and cardiovascular death in the XANTUS population.

METHODS AND RESULTS

Causes of death occurring within a year after rivaroxaban initiation in patients in the XANTUS programme studies were adjudicated by a central adjudication committee and classified following international guidance. Baseline characteristics associated with all-cause or cardiovascular death were identified. Of 11 040 patients, 187 (1.7%) died. Almost half of these deaths were due to cardiovascular causes other than bleeding (n = 82, 43.9%), particularly heart failure (n = 38, 20.3%) and sudden or unwitnessed death (n = 24, 12.8%). Fatal stroke (n = 8, 4.3%), which was classified as a type of cardiovascular death, and fatal bleeding (n = 17, 9.1%) were less common causes of death. Independent factors associated with all-cause or cardiovascular death included age, AF type, body mass index, left ventricular ejection fraction, hospitalization at baseline, rivaroxaban dose, and anaemia.

CONCLUSION

The overall risk of death due to stroke or bleeding was low in XANTUS. Anticoagulated patients with AF remain at risk of death due to heart failure and sudden death. Potential interventions to reduce cardiovascular deaths in anticoagulated patients with AF require further investigation, e.g. early rhythm control therapy and AF ablation.

TRIAL REGISTRATION NUMBERS

NCT01606995, NCT01750788, NCT01800006.

Arrhythmias and ion channelopathies causing sudden cardiac death in Hispanic/Latino and Indigenous populations

The limited literature and increasing interest in studies on cardiac electrophysiology, explicitly focusing on cardiac ion channelopathies and sudden cardiac death in diverse populations, has prompted a comprehensive examination of existing research. Our review specifically targets Hispanic/Latino and Indigenous populations, which are often underrepresented in healthcare studies. This review encompasses investigations into genetic variants, epidemiology, etiologies, and clinical risk factors associated with arrhythmias in these demographic groups. The review explores the Hispanic paradox, a phenomenon linking healthcare outcomes to socioeconomic factors within Hispanic communities in the United States. Furthermore, it discusses studies exemplifying this observation in the context of arrhythmias and ion channelopathies in Hispanic populations. Current research also sheds light on disparities in overall healthcare quality in Indigenous populations. The available yet limited literature underscores the pressing need for more extensive and comprehensive research on cardiac ion channelopathies in Hispanic/Latino and Indigenous populations. Specifically, additional studies are essential to fully characterize pathogenic genetic variants, identify population-specific risk factors, and address health disparities to enhance the detection, prevention, and management of arrhythmias and sudden cardiac death in these demographic groups.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Atrial fibrillation ablation in heart failure patients: Where do we stand in 2023? - State of the art review

Atrial fibrillation (AF) and heart failure are common overlapping cardiovascular disorders. Despite important therapeutic advances over the past several decades, controversy persists about whether a rate control or rhythm control approach constitutes the best option in this population. There is also considerable debate about whether antiarrhythmic drug therapy or ablation is the best approach when rhythm control is pursued.  A brief historical examination of the literature addressing this issue will be performed. An analysis of several important clinical outcomes observed in the prospective, randomized studies, which have compared AF ablation to non-ablation treatment options, will be discussed. This review will conclude with recommendations to guide clinicians on the status of AF ablation as a treatment option when considering management options in heart failure patients with atrial fibrillation.

Brady- and tachyarrhythmias detected by continuous rhythm monitoring in paroxysmal atrial fibrillation

OBJECTIVE

Atrial fibrillation (AF) is associated with adverse events including conduction disturbances, ventricular arrhythmias and sudden death. The aim of this study was to examine brady- and tachyarrhythmias using continuous rhythm monitoring in patients with paroxysmal self-terminating AF (PAF).

METHODS

In this multicentre observational substudy to the Reappraisal of Atrial Fibrillation: interaction between hyperCoagulability, Electrical remodelling and Vascular destabilisation in the progression of AF (RACE V), we included 392 patients with PAF and at least 2 years of continuous rhythm monitoring. All patients received an implantable loop recorder, and all detected episodes of tachycardia ≥182 beats per minute (BPM), bradycardia ≤30 BPM or pauses ≥5 s were adjudicated by three physicians.

RESULTS

Over 1272 patient-years of continuous rhythm monitoring, we adjudicated 1940 episodes in 175 patients (45%): 106 (27%) patients experienced rapid AF or atrial flutter (AFL), pauses ≥5 s or bradycardias ≤30 BPM occurred in 47 (12%) patients and in 22 (6%) patients, we observed both episode types. No sustained ventricular tachycardias occurred. In the multivariable analysis, age >70 years (HR 2.3, 95% CI 1.4 to 3.9), longer PR interval (HR 1.9, 1.1-3.1), CHA2DS2-VASc score ≥2 (HR 2.2, 1.1-4.5) and treatment with verapamil or diltiazem (HR 0.4, 0.2-1.0) were significantly associated with bradyarrhythmia episodes. Age >70 years was associated with lower rates of tachyarrhythmias.

CONCLUSIONS

In a cohort exclusive to patients with PAF, almost half experienced severe bradyarrhythmias or AF/AFL with rapid ventricular rates. Our data highlight a higher than anticipated bradyarrhythmia risk in PAF.

TRIAL REGISTRATION NUMBER

NCT02726698.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Atrial Fibrillation and the Risk of Ventricular Arrhythmias and Cardiac Arrest: A Nationwide Population-Based Study

BACKGROUND

Atrial fibrillation (AF) has been linked to an increased risk of ventricular arrhythmias (VAs) and sudden death. We investigated this association in hospitalised patients in France.

METHODS

All hospitalised patients from 2013 were identified from the French National database and included if they had at least 5 years of follow-up data.

RESULTS

Overall, 3,381,472 patients were identified. After excluding 35,834 with a history of VAs and cardiac arrest, 3,345,638 patients were categorised into two groups: no AF (n = 3,033,412; mean age 57.2 ± 21.4; 54.3% female) and AF (n = 312,226; 78.1 ± 10.6; 44.0% female). Over a median follow-up period of 5.4 years (interquartile range (IQR) 5.0-5.8 years), the incidence (2.23%/year vs. 0.56%/year) and risk (hazard ratio (HR) 3.657 (95% confidence interval (CI) 3.604-3.711)) of VAs and cardiac arrest were significantly higher in AF patients compared to non-AF patients. This was still significant after adjusting for confounders, with a HR of 1.167 (95% CI 1.111-1.226) and in the 1:1 propensity score-matched analysis (n = 289,332 per group), with a HR of 1.339 (95% CI 1.313-1.366). In the mediation analysis, the odds of cardiac arrest were significantly mediated by AF-associated VAs, with an OR of 1.041 (95% CI 1.040-1.042).

CONCLUSION

In hospitalised French patients, AF was associated with an increased risk of VAs and sudden death.

Sinus rhythm restoration and improved outcomes in patients with acute ischemic stroke and in-hospital paroxysmal atrial fibrillation

AIMS

It is unclear whether early cardiac rhythm control is beneficial in patients with acute ischemic stroke and paroxysmal atrial fibrillation (PAF). We sought to investigate whether PAF self-termination and in-hospital sinus rhythm (SR) restoration is associated with improved outcome in ischemic stroke patients with PAF, compared to those with sustained atrial fibrillation (AF).

METHODS

Consecutive patients with first-ever acute stroke and confirmed PAF during hospitalization were followed for up to 10 years after the index stroke or until death. We investigated the association of in-hospital self-terminated PAF and PAF conversion to SR compared to sustained AF with 10-year all-cause mortality, stroke recurrence, and major adverse cardiovascular events (MACE). Cox regression analysis was performed to identify independent predictors of each outcome.

RESULTS

Among 297 ischemic stroke patients with in-hospital PAF detection, PAF was self-terminated in 87 (29.3%) patients, while 143 (48.1%) patients received antiarrhythmic medication in order to achieve PAF conversion to SR. During a median (Interquartile range, IQR) period of 28 (4-68) months, among patients with self-terminated PAF there were 13.5 deaths, 3.6 stroke recurrences, and 5.3 MACE per 100 patient-year while in patients who underwent medical PAF conversion there were 11.7 deaths, 4.6 stroke recurrences, and 5.8 MACE per 100 patient-year. Patients with sustained AF experienced 23.8 deaths, 8.7 stroke recurrences, and 13.9 MACE per 100 patient-years. In multivariable analysis, compared to patients with sustained AF, PAF self-termination was associated with significantly lower 10 years-risk of death (adjusted hazards ratio (adjHR): HR: 0.63, 95% Confidence interval: 0.40-0.96), stroke recurrence (adjHR: HR: 0.41, 95% CI: 0.19-0.91), and MACE (adjHR: 0.43, 95% CI: 0.23-0.81), while PAF medical conversion to SR was associated with lower 10 years-risk of death (adjHR: 0.65, 95% CI: 0.44-0.97) and MACE (adjHR: 0.56, 95% CI: 0.33-0.95).

DISCUSSION

This study showed that in-hospital PAF self-termination was associated with lower risk of 10-year mortality, stroke recurrence, and MACE, potentially attributed to the lower burden of AF, whereas in-hospital PAF conversion to SR was associated with lower risk of 10-year mortality and MACE.

CONCLUSION

Early restoration of sinus rhythm is associated with improved survival and MACE in patients with acute ischemic stroke and PAF.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Prevalence of sudden cardiac death in dogs with atrial fibrillation

Background

Atrial fibrillation (AF) is associated with increased risk of sudden cardiac death (SCD) in humans, independent of secondary risk factors such as thrombogenic disorders. In dogs, SCD is described in a number of heart diseases, but an association between AF and SCD is unreported.

Hypothesis

(a) A higher proportion of dogs with AF will experience SCD, and (b) SCD will be associated with complex ventricular arrhythmias.

Animals

One‐hundred forty‐two dogs with AF, and 127 dogs without AF.

Methods

Retrospective, multicenter, case‐control study. Dogs included in the AF group were compared to a control group of dogs in sinus rhythm, matched for echocardiographic diagnosis. Descriptive statistics were used to identify proportions of each group suffering SCD, compared using chi‐squared testing. Risk factors for SCD in dogs with AF were evaluated at the univariable and multivariable level using binary logistic regression. Significance was P < .05.

Results

A significantly higher proportion of dogs with AF suffered SCD than dogs in the control group (14.8% vs 5.5%; P = .01). Younger age at diagnosis, larger left atrial size, and a history of syncope all were independent predictors of SCD in dogs with AF (χ², 16.3; P = .04).

Conclusions and Clinical Importance

Atrial fibrillation was associated with a higher prevalence of SCD in dogs. A history of syncope may be a useful predictor of SCD risk.

Impact of Atrial Fibrillation on Hospitalization Outcomes of Heart Failure in Patients ≥ 60 Years with Implantable Cardioverter Defibrillator

The impact of atrial fibrillation (AF) on the hospitalization outcomes in patients ≥ 60 years of age with implantable cardioverter defibrillators (ICD) is not well studied. We queried the National Inpatient Sample database for all patients aged ≥ 60 who had a history of ICD placement, and were admitted with a primary diagnosis of heart failure (HF) during the years 2016-2017. Patients were stratified into 2 groups based on their history of AF. The primary outcome of the study was all-cause in-hospital mortality. Secondary outcomes included cardiogenic shock, myocardial infarction (MI), ventricular fibrillation (VF), stroke and acute kidney injury (AKI). The association between different age strata and outcomes was investigated. The hospitalization outcomes were modeled using logistic regression. A total of 178,045 patients were included, of whom 56.2% had AF. AF correlated with increased mortality (A-OR 1.22 (95% CI: 1.06-1.4), p=0.005), cardiogenic shock (A-OR 1.21 (95%CI: 1.08-1.36), p<0.001), AKI (A-OR 1.12 (95%CI: 1.06-1.17), p<0.001 and lower risk for MI (A-OR 0.79 (95% CI: 0.68-0.9), p<0.001. There was no correlation between AF and risk for VF or stroke. A significant correlation between AF and higher risk for mortality, cardiogenic shock and AKI was demonstrated in ages ≤ 75, ≤ 75, and ≤ 80 years, respectively. In contrast, a significant correlation between AF and lower risk for MI is only demonstrated at age > 70 years. We conclude that AF is an independent predictor for increased all-cause in-hospital mortality and cardiogenic shock. Such risk is influenced by age.

Electrocardiographic Findings and In-Hospital Mortality of COVID-19 Patients; a Retrospective Cohort Study

Background:

Although current evidence points to the possible prognostic value of electrocardiographic (ECG) findings for in-hospital mortality of COVID-19 patients, most of these studies have been performed on a small sample size. In this study, our aim was to investigate the ECG changes as prognostic indicators of in-hospital mortality.

Methods:

In a retrospective cohort study, the findings of the first and the second ECGs of COVID-19 patients were extracted and changes in the ECGs were examined. Any abnormal finding in the second ECG that wasn’t present in the initial ECG at the time of admission was defined as an ECG change. ECGs were interpreted by a cardiologist and the prognostic value of abnormal ECG findings for in-hospital mortality of COVID-19 patients was evaluated using multivariate analysis and the report of the relative risk (RR).

Results:

Data of the ECGs recorded at the time of admission were extracted from the files of 893 patients; likewise, the second ECGs could be extracted from the records of 328 patients who had an initial ECG. The presence of sinus tachycardia (RR = 2.342; p <0.001), supraventricular arrhythmia (RR = 1.688; p = 0.001), ventricular arrhythmia (RR = 1.854; p = 0.011), interventricular conduction delays (RR = 1.608; p = 0.009), and abnormal R wave progression (RR = 1.766; p = 0.001) at the time of admission were independent prognostic factors for in-hospital mortality. In the second ECG, sinus tachycardia (RR = 2.222; p <0.001), supraventricular arrhythmia (RR = 1.632; p <0.001), abnormal R wave progression (RR = 2.151; p = 0.009), and abnormal T wave (RR = 1.590; p = 0.001) were also independent prognostic factors of in-hospital mortality. Moreover, by comparing the first and the second ECGs, it was found that the incidence of supraventricular arrhythmia (RR = 1.973; p = 0.005) and ST segment elevation/depression (RR = 2.296; p <0.001) during hospitalization (ECG novel changes) are two independent prognostic factors of in-hospital mortality in COVID-19 patients.

Conclusion:

Due to the fact that using electrocardiographic data is easy and accessible and it is easy to continuously monitor patients with this tool, ECGs can be useful in identifying high-risk COVID-19 patients for mortality.

Sudden Cardiac Death in Patients with Heart Disease and Preserved Systolic Function: Current Options for Risk Stratification

Sudden cardiac death (SCD) is the leading cause of cardiovascular mortality in patients with coronary artery disease without severe systolic dysfunction and in heart failure with preserved ejection fraction. From a global health perspective, while risk may be lower, the absolute number of SCDs in patients with left ventricle ejection fraction >35% is higher than in those with severely reduced left ventricle ejection fraction (defined as ≤35%). Despite these observations and the high amount of available data, to date there are no clear recommendations to reduce the sudden cardiac death burden in the population with mid-range or preserved left ventricle ejection fraction. Ongoing improvements in risk stratification based on electrophysiological and imaging techniques point towards a more precise identification of patients who would benefit from ICD implantation, which is still an unmet need in this subset of patients. The aim of this review is to provide a state-of-the-art approach in sudden cardiac death risk stratification of patients with mid-range and preserved left ventricular ejection fraction and one of the following etiologies: ischemic cardiomyopathy, heart failure, atrial fibrillation or myocarditis.

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSIONS

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

TRANSLATIONAL PERSPECTIVE

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

[Atrial Fibrillation and Mortality: Prognostic Factors and Direction of Prevention]

This review focuses on major causes and risk factors for death of patients with atrial fibrillation (AF). The authors analyzed current therapeutic strategies for managing patients with AF with respect of their effects on prediction and mortality. Special attention is paid to the strategy of rhythm control and the clinical significance of catheter ablation in the treatment of patients with AF and heart failure.

Heart Disease and Stroke Statistics-2021 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2021 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors related to cardiovascular disease.

RESULTS

Each of the 27 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Catheter Ablation Compared with Medical Therapy for Atrial Fibrillation with Heart Failure: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Background: The optimal strategy for patients with coexisting atrial fibrillation (AF) and heart failure (HF) was not settled. Our purpose was to conduct a systematic review and meta-analysis of randomized controlled trials to evaluate the effect of catheter ablation compared with medical therapy for AF on mortality, HF hospitalization, left ventricular (LV) function, and quality of life among patients with HF and AF. Materials and Methods: We searched Pubmed (1966 to September 20, 2019), EMBASE (1966 to September 20, 2019), the Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov for randomized controlled trials with a comparison of catheter ablation for AF with medical therapy among patients with coexisting AF and HF. Risk ratio (RR) or mean difference (MD) with 95% confidence interval (CI) was used as a measure of the effect of catheter ablation versus medical therapy on endpoints. Our final analysis included 6 randomized control trials with 775 patients. Results: Pooled results from the random-effects model showed that compared with medical therapy for AF, catheter ablation was associated with reduced all-cause mortality (RR 0.52, 95%Cl, 0.35 to 0.76) and HF hospitalization (RR 0.56, 95%Cl, 0.44 to 0.71), as well as increased LV ejection fraction (LVEF), distance walked in six minutes, and improvements in quality of life. Conclusions: This updated meta-analysis showed that compared to medical therapy, catheter ablation for AF was associated with significant benefits in several key clinical and biomarker endpoints, including reductions in all-cause mortality and HF hospitalization.

Atrial fibrillation, anticoagulation management and risk of stroke in the Cardiomyopathy/Myocarditis registry of the EURObservational Research Programme of the European Society of Cardiology

Aims

Cardiomyopathies are a heterogeneous group of disorders that increase the risk for atrial fibrillation (AF). The aim of the study is to assess the prevalence of AF, anticoagulation management, and risk of stroke/transient ischaemic attack (TIA) in patients with cardiomyopathy.

Methods and results

Three thousand two hundred eight consecutive adult patients with cardiomyopathy (34.9% female; median age: 55.0 years) were prospectively enrolled as part of the EURObservational Research Programme Cardiomyopathy/Myocarditis Registry. At baseline, 903 (28.2%) patients had AF (29.4% dilated, 27.5% hypertrophic, 51.5% restrictive, and 14.7% arrhythmogenic right ventricular cardiomyopathy, P < 0.001). AF was associated with more advanced New York Heart Association class (P < 0.001), increased prevalence of cardiovascular risk factors and co‐morbidities, and a history of stroke/TIA (P < 0.001). Oral anticoagulation was administered in 71.7% of patients with AF (vitamin K antagonist: 51.6%; direct oral anticoagulant: 20.1%). At 1 year follow‐up, the incidence of cardiovascular endpoints was as follows: stroke/TIA 1.85% (AF vs. non‐AF: 3.17% vs. 1.19%, P < 0.001), death from any cause 3.43% (AF vs. non‐AF: 5.39% vs. 2.50%, P < 0.001), and death from heart failure 1.67% (AF vs. non‐AF: 2.44% vs. 1.31%, P = 0.033). The independent predictors for stroke/TIA were as follows: AF [odds ratio (OR) 2.812, P = 0.005], history of stroke (OR 7.311, P = 0.010), and anaemia (OR 3.119, P = 0.006).

Conclusions

The study reveals a high prevalence and diverse distribution of AF in patients with cardiomyopathies, inadequate anticoagulation regimen, and high risk of stroke/TIA in this population.

Myocardial cathepsin D is downregulated in sudden cardiac death

Cathepsins are the major lysosomal proteases that maintain intracellular homeostasis. Herein, we investigated the alterations in myocardial cathepsin expression during aging, cardiac hypertrophy, and sudden cardiac death (SCD). Cardiac tissue and blood were sampled from autopsy cases. Subjects were classified into three groups: SCD with cardiac hypertrophy (SCH), compensated cardiac hypertrophy (CCH), and control. Immunoblotting was performed for the major cardiac cathepsins and their targets: cathepsin B, D, and L (CTSB/D/L), p62, ATP synthase subunit c (ATPSC), and α-synuclein (ASNC). Immunohistochemical analysis and ELISA using serum samples were performed for CTSD. Cardiac CTSB and CTSD were upregulated with age (r = 0.63 and 0.60, respectively), whereas the levels of CTSL, p62, ATPSC, and ASNC remained unchanged. In age-matched groups, cardiac CTSD was significantly downregulated in SCH (p = 0.006) and CTSL was moderately downregulated in CCH (p = 0.021); however, p62, ATPSC, and ASNC were not upregulated in cardiac hypertrophy. Immunohistochemistry also revealed decreased myocardial CTSD levels in SCH, and serum CTSD levels were relatively lower in SCH cases. Overall, these results suggest that upregulation of cardiac CTSB and CTSD with age may compensate for the elevated proteolytic demand, and that downregulation of CTSD is potentially linked to SCH.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Towards chamber specific heart-on-a-chip for drug testing applications

Modeling of human organs has long been a task for scientists in order to lower the costs of therapeutic development and understand the pathological onset of human disease. For decades, despite marked differences in genetics and etiology, animal models remained the norm for drug discovery and disease modeling. Innovative biofabrication techniques have facilitated the development of organ-on-a-chip technology that has great potential to complement conventional animal models. However, human organ as a whole, more specifically the human heart, is difficult to regenerate in vitro, in terms of its chamber specific orientation and its electrical functional complexity. Recent progress with the development of induced pluripotent stem cell differentiation protocols, made recapitulating the complexity of the human heart possible through the generation of cells representative of atrial & ventricular tissue, the sinoatrial node, atrioventricular node and Purkinje fibers. Current heart-on-a-chip approaches incorporate biological, electrical, mechanical, and topographical cues to facilitate tissue maturation, therefore improving the predictive power for the chamber-specific therapeutic effects targeting adult human. In this review, we will give a summary of current advances in heart-on-a-chip technology and provide a comprehensive outlook on the challenges involved in the development of human physiologically relevant heart-on-a-chip.

Association Between Digoxin Use and Adverse Outcomes Among Patients in the Chinese Atrial Fibrillation Registry

INTRODUCTION

Digoxin is widely used in patients with atrial fibrillation (AF), but its association with adverse outcomes remains controversial.

OBJECTIVE

We aimed to assess the association between digoxin and adverse outcomes in Chinese patients with AF.

METHODS

We used data from the Chinese Atrial Fibrillation Registry, a prospective, multicenter, hospital-based registry study involving 31 hospitals. In total, 10,472 eligible patients with AF, enrolled from August 2011 to December 2016, were included in this study. The association between digoxin use and all-cause mortality, cardiovascular death, and cardiovascular hospitalization were investigated using Cox proportional hazards models.

RESULTS

In total, 1152 (11%) patients were treated with digoxin at baseline. Patients receiving digoxin were older (mean age 69.7 vs. 66.5 years) and had a higher heart rate (92.4 vs. 79.7 beats/min). A higher proportion of patients receiving digoxin therapy had a history of heart failure (62.5 vs. 15.6%), diabetes mellitus (34.4 vs. 24.4%), and persistent AF (67.9 vs. 38.4%). Digoxin use was independently associated with increased all-cause mortality (adjusted hazard ratio (aHR) 1.21; 95% confidence interval (CI) 1.02-1.43; p = 0.031), cardiovascular death (aHR 1.25; 95% CI 1.01-1.55; p = 0.043), and cardiovascular hospitalization (aHR 1.21; 95% CI 1.05-1.39; p = 0.007). The associations were also homogeneous across various subgroups except in patients with and without renal dysfunction (p value for interaction = 0.029).

DISCUSSION

In this Chinese AF cohort, for patients who had not undergone ablation, digoxin use was associated with a significant increase in adverse outcomes. Although residual confounders may exist, and serum concentrations of digoxin were unavailable, digoxin should be used with caution in clinical practice, and its effects need to be critically evaluated in randomized trials.

CLINICAL TRIAL REGISTRATION

URL: http://www.chictr.org.cn/showproj.aspx?proj=5831. Unique identifier: ChiCTR-OCH-13003729.

Epidemiology of atrial fibrillation in northeast China: a cross-sectional study, 2017–2019

Objective

To evaluate the epidemiology of atrial fibrillation (AF) in northeast China.

Methods

This cross-sectional survey using a multistage, stratified and cluster random sampling method was conducted in Liaoning Province between September 2017 and March 2019. A total of 18 796 participants (28.9% urban, 71.1% rural) aged ≥40 years were included. All participants completed a questionnaire and underwent a physical examination and ECG. AF was diagnosed according to history and ECG findings.

Results

The overall AF prevalence was 1.1%; it increased steeply with age. AF was more prevalent in men than in women (1.5% vs 0.9%, p<0.001); however, the difference between urban and rural areas was not significant (1.3% vs 1.1%, p=0.228). Among the AF population, the overall AF awareness rate was 52.6%, higher in women than in men (61.5% vs 44.1%, p=0.011); however, the difference between areas was not statistically significant (60.0% vs 49.0%, p=0.129). According to the CHA2DS-VASc score, almost all (90.2%, 194/215) of our subjects required oral anticoagulant (OAC) therapy; however, only 4.1% actually received it. Moreover, hypertension (66.5%), dyslipidaemia (32.6%) and diabetes (24.2%) were highly prevalent in patients with AF, but their control rates were unacceptably low (7.0%, 8.6% and 28.8%, respectively).

Conclusions

The burden of AF in northeast China was substantial. Underuse of OAC therapy and uncontrolled comorbidities will likely contribute to the cardiovascular outcomes of patients with AF in the coming decades. Long-term management strategies for AF and related risk factors are required in northeast China.

Atrial Fibrillation Is Associated with Increased Mortality in Patients Presenting with Ventricular Tachyarrhythmias

Heterogenous data about the prognostic impact of atrial fibrillation (AF) in patients with ventricular tachyarrhythmias exist. Therefore, this study evaluates this impact of AF in patients presenting with ventricular tachyarrhythmias. 1,993 consecutive patients presenting with ventricular tachyarrhythmias (i.e. ventricular tachycardia and fibrillation (VT, VF)) on admission at one institution were included (from 2002 until 2016). All medical data of index and follow-up hospitalizations were collected during the complete follow-up period for each patient. Statistics comprised univariable Kaplan-Meier and multivariable Cox regression analyses in the unmatched consecutive cohort and after propensity-score matching for harmonization. The primary prognostic endpoint was long-term all-cause mortality at 2.5 years. AF was present in 31% of patients presenting with index ventricular tachyarrhythmias on admission (70% paroxysmal, 9% persistent, 21% permanent). VT was more common (67% versus 59%; p = 0.001) than VF (33% versus 41%; p = 0.001) in AF compared to non-AF patients. Long-term all-cause mortality at 2.5 years occurred more often in AF compared to non-AF patients (mortality rates 40% versus 24%, log rank p = 0.001; HR = 1.825; 95% CI 1.548-2.153; p = 0.001), which may be attributed to higher rates of all-cause mortality at 30 days, in-hospital mortality and mortality after discharge (p < 0.05) (secondary endpoints). Mortality differences were observed irrespective of index ventricular tachyarrhythmia (VT or VF), LV dysfunction or presence of an ICD. In conclusion, this study identifies AF as an independent predictor of death in patients presenting consecutively with ventricular tachyarrhythmias.

4D cardiac electromechanical activation imaging

Cardiac abnormalities, a major cause of morbidity and mortality, affect millions of people worldwide. Despite the urgent clinical need for early diagnosis, there is currently no noninvasive technique that can infer to the electrical function of the whole heart in 3D and thereby localize abnormalities at the point of care. Here we present a new method for noninvasive 4D mapping of the cardiac electromechanical activity in a single heartbeat for heart disease characterization such as arrhythmia and infarction. Our novel technique captures the 3D activation wave of the heart in vivo using high volume-rate (500 volumes per second) ultrasound with a 32 × 32 matrix array. Electromechanical activation maps are first presented in a normal and infarcted cardiac model in silico and in canine heart during pacing and re-entrant ventricular tachycardia in vivo. Noninvasive 4D electromechanical activation mapping in a healthy volunteer and a heart failure patient are also determined. The technique described herein allows for direct, simultaneous and noninvasive visualization of electromechanical activation in 3D, which provides complementary information on myocardial viability and/or abnormality to clinical imaging.

Atrial fibrillation and risk of major arrhythmic events in Brugada syndrome: A meta-analysis

BACKGROUND

Brugada syndrome (BrS) is a common cause of sudden cardiac death (SCD). There is recent evidence that atrial fibrillation (AF) is associated with increased risk of SCD in general population. However, whether AF increases a risk of major arrhythmic events (MAE) in patients with BrS is still unclear. We performed a systematic review and meta-analysis to explore the effect of AF on MAE in BrS population.

METHODS

We searched the databases of MEDLINE and EMBASE from inception to March 2019. Included studies were published cohort studies reporting rates of MAE (ventricular fibrillation, sustained ventricular tachycardia, SCD, or sudden cardiac arrest) in BrS patients, with and without previous documented AF. Data from each study were combined using the random-effects model.

RESULTS

Six studies from 1,703 patients were included. There was a significant association between AF and an increased risk of MAE in patients with BrS (pooled OR = 2.37, 95% CI = 1.36-4.13, p-value = .002, I²  = 40.3%).

CONCLUSIONS

Our meta-analysis demonstrated that AF is associated with an increased risk of MAE in patients with BrS.

Incidence and Predictors of Sudden Cardiac Death After a Major Non-Fatal Cardiovascular Event

BACKGROUND

Sudden cardiac death (SCD) still accounts for the majority of deaths from the four major cardiovascular events (myocardial infarction (MI), heart failure (HF), atrial fibrillation (AF), and stroke) despite substantial progress on prevention.

METHODS

Four separate cohorts (one for each of the four major cardiovascular conditions) were captured through person-linked hospital morbidity and mortality data collections between 2000 and 2009 and followed-up for 11.5 years. The incidence rate for each cohort was total SCD cases divided by sum of follow-up time for each individual alive. Kaplan-Meier survival curve was used to calculate unadjusted risk of SCD. Predictors of SCD were identified by fitting multivariable adjusted Cox regression models in each of the cohorts.

RESULTS

There were 1,174 cases of SCD from 53,614 total CVD events across the cohorts (35.6% for MI, 15.6% for HF, 22.4% for AF, 26.4% for stroke). The incidence rate and unadjusted risk of SCD were both highest after incident hospitalisation for HF, followed by MI, stroke and AF. The elevated risk of SCD was independently associated with MI, HF, arrhythmias, peripheral artery disease, diabetes, chronic kidney disease, and prior coronary heart disease (hazard ratios ranging from 1.1 to 2.8). Early revascularisation is protective in 28-day survivors after an incident MI event.

CONCLUSIONS

An appreciable incidence of SCD following an incident event of MI, HF, AF and stroke deserves greater prevention efforts. Major medical conditions such as MI, HF, peripheral artery disease, and arrhythmias are risk markers of SCD and coronary revascularisation is protective.

A Comparison of Patient History- and EKG-based Cardiac Risk Scores

Patient-specific risk scores are used to identify individuals at elevated risk for cardiovascular disease. Typically, risk scores are based on patient habits and medical history - age, sex, race, smoking behavior, and prior vital signs and diagnoses. We explore an alternative source of information, a patient's raw electrocardiogram recording, and develop a score of patient risk for various outcomes. We compare models that predict adverse cardiac outcomes following an emergency department visit, and show that a learned representation (e.g. deep neural network) of raw EKG waveforms can improve prediction over traditional risk factors. Further, we show that a simple model based on segmented heart beats performs as well or better than a complex convolutional network recently shown to reliably automate arrhythmia detection in EKGs. We analyze a large cohort of emergency department patients and show evidence that EKG-derived scores can be more robust to patient heterogeneity.

P Wave Indices-Advancing Our Understanding of Atrial Fibrillation-Related Cardiovascular Outcomes

Atrial fibrillation (AF) is associated with an increased risk of ischemic stroke, heart failure, cognitive decline, dementia, myocardial infarction, sudden cardiac death (SCD), and all-cause death. Although these associations are firmly established, our understanding of the underlying mechanisms remains incomplete. Accumulating evidence suggests that left atrial (LA) abnormality or atrial cardiomyopathy may explain the relationship of AF to the aforementioned outcomes. P-wave indices (PWIs) reflect underlying atrial remodeling. In this mini review, we define representative PWIs, discuss state-of-the-art knowledge on the relationship between abnormal PWIs and AF-related cardiovascular outcomes (focusing on ischemic stroke and sudden cardiac death), and propose directions for future research. Our ultimate goal is to present a practical way forward to advance the emerging field of LA abnormality or atrial cardiomyopathy.

A Platform for Generation of Chamber-Specific Cardiac Tissues and Disease Modeling

Tissue engineering using cardiomyocytes derived from human pluripotent stem cells holds a promise to revolutionize drug discovery, but only if limitations related to cardiac chamber specification and platform versatility can be overcome. We describe here a scalable tissue-cultivation platform that is cell source agnostic and enables drug testing under electrical pacing. The plastic platform enabled on-line noninvasive recording of passive tension, active force, contractile dynamics, and Ca2+ transients, as well as endpoint assessments of action potentials and conduction velocity. By combining directed cell differentiation with electrical field conditioning, we engineered electrophysiologically distinct atrial and ventricular tissues with chamber-specific drug responses and gene expression. We report, for the first time, engineering of heteropolar cardiac tissues containing distinct atrial and ventricular ends, and we demonstrate their spatially confined responses to serotonin and ranolazine. Uniquely, electrical conditioning for up to 8 months enabled modeling of polygenic left ventricular hypertrophy starting from patient cells.

Usefulness of the CHA2DS2-VASc Score to Predict the Risk of Sudden Cardiac Death and Ventricular Arrhythmias in Patients With Atrial Fibrillation

Sudden cardiac death (SCD), the most devastating manifestation of ventricular arrhythmias (VAs), is the leading cause of mortality in patients with atrial fibrillation (AF). We hypothesized that the CHA₂DS₂-VASc score, consisting of age and several clinical risk factors, could be used to estimate the individual risk of SCD/VAs for AF patients. From year 2000 to 2011, 288,181 newly-diagnosed AF patients without antecedent SCD/VAs were identified from "Taiwan National Health Insurance Research Database." During the follow-up of 1,065,751 person-years, 11,166 patients experienced SCD/VAs with an annual risk of 1.05% which increased from 0.34% for patients with a CHA₂DS₂-VASc score of 0% to 2.63% for those with a score of 9. The CHA₂DS₂-VASc score was a significant predictor of SCD/VAs with an adjusted hazard ratio of 1.21 (95% confidence interval 1.20 to 1.22) per 1 point increment of the score. As the CHA₂DS₂-VASc score increased from 1 to 9, the hazard ratio of SCD/VAs continuously increased from 1.28 to 4.17 compared with patients with a CHA₂DS₂-VASc score of 0. In conclusion, CHA₂DS₂-VASc score was a convenient scoring system which could be used to predict the risk of SCD/VAs in AF patients in addition to its ability for stroke risk stratification.

Holter monitoring demonstrates that ventricular arrhythmias are common in cats with decompensated and compensated hypertrophic cardiomyopathy

Arrhythmias can complicate cardiac disease in cats and are a potential cause of sudden death. The aim of this study was to evaluate the presence and nature of cardiac arrhythmias, and the potential correlation between plasma serum troponin I (cTnI) concentrations and the presence or severity of arrhythmias in cats with decompensated (dHCM) and compensated hypertrophic cardiomyopathy (cHCM). Forty one client-owned cats were studied: 16 with cHCM, 15 with dHCM and 10 healthy control cats. Physical examination, echocardiography, cTnI and 24-h Holter recordings were obtained in all cats and thoracic radiographs in cats with dHCM. Cats in both HCM groups were followed for 1 year after their initial Holter examination. The median (range) number of ventricular premature complexes (VPCs) over 24h was 867 (1-35,160) in cats with dHCM, 431 (0-18,919) in cats with cHCM and 2 (0-13) in healthy control cats. The median number of episodes of ventricular tachycardia (VTach) was 0 (0-1497) in dHCM and 0.5 (0-91) in cats with cHCM. The number of VPCs, VTach episodes and heart rate was not different between the HCM groups. Plasma serum troponin I was highest in the cats with dHCM, but there was no correlation between cTnI concentration and the number of arrhythmias. Thirteen of 31 cats with HCM died, but an association with the presence and complexity of ventricular arrhythmias was not observed. Compared to healthy cats, ventricular arrhythmias were common in cats with cHCM and dHCM, but neither presence nor complexity of arrhythmias could be linked to prognosis.

Comparative Clinical Outcomes of Edoxaban in Adults With Nonvalvular Atrial Fibrillation

BACKGROUND

A critical appraisal of all pooled evidence regarding novel oral anticoagulants (NOACs) for stroke prevention regardless of publication status or study design has not been conducted yet. Being the latest addition to NOACs, the data on edoxaban are especially scarce.

STUDY QUESTION

What are the comparative clinical outcomes of edoxaban versus warfarin and other NOACs apixaban, dabigatran, or rivaroxaban in adults with nonvalvular atrial fibrillation?

DATA SOURCES

Randomized controlled trials (RCTs), observational studies, and network meta-analyses were identified in PubMed, EMBASE, the Cochrane Library, Pharmapendium, Elsevier Clinical Pharmacology, and the clinicaltrials.gov trial registry in June 2018.

STUDY DESIGN

Rapid review per a priori developed protocol, direct frequentist random-effects meta-analysis of aggregate data, grading the quality of evidence per the Grading of Recommendations Assessment, Development and Evaluation working group approach.

RESULTS

Direct 4 RCTs (23,021 patients) suggest that edoxaban is noninferior to warfarin in prevention of stroke and systemic embolism [pooled relative risk (RR): 0.65, 95% confidence interval (CI): 0.23-1.81, 2 RCTs] and reduces the risk of cardiovascular mortality (RR: 0.87, 95% CI: 0.78-0.97, 1 RCT), major cardiovascular morbidity (RR: 0.90, 95% CI: 0.82-0.98, 2 RCTs), and major bleeding events (RR: 0.80, 95% CI: 0.71-0.91, 1 RCT) but increases the risk of gastrointestinal bleeding (RR: 1.21, 95% CI: 1.01-1.46, 1 RCT) and anemia (RR: 1.45, 95% CI: 1.05-1.99, 3 RCTs). Edoxaban is superior to warfarin in patients with increased risk of bleeding with warfarin because of variants in CYP2C9 and VKORC1 genes. Indirect evidence does not allow valid conclusions regarding comparative superiority of NOACs. The quality of evidence was downgraded because of reporting bias, small number of events, and indirectness in comparisons.

CONCLUSIONS

Edoxaban is a welcome addition to the NOAC's armamentarium. However, the comparative data with other novel NOACs are mostly nonexisting, and urgently needed for better individual patient assessment.

Quantification of Ventricular Repolarization Variation for Sudden Cardiac Death Risk Stratification in Atrial Fibrillation

OBJECTIVE

Atrial fibrillation (AF) rhythm gives rise to an irregular response in ventricular activity, preventing the use of standard ECG-derived risk markers based on ventricular repolarization heterogeneity under this particular condition. In this study, we proposed new indices to quantify repolarization variations in AF patients, assessing their stratification performance in a chronic heart failure population with AF.

METHODS

We developed a method based on a selective bin averaging technique. Consecutive beats preceded by a similar RR interval were selected, from which the average variation within the ST-T complex for each RR range was computed. We proposed two sets of indices: 1) the 2-beat index of ventricular repolarization variation, ( I_V2), computed from pairs of stable consecutive beats; and 2) the 3-beat indices of ventricular repolarization variation, computed in triplets of stable consecutive beats ( I_V3).

RESULTS

These indices showed a significant association with sudden cardiac death (SCD) outcome in the study population. In addition, risk assessment based on the combination of the proposed indices improved stratification performance compared to their individual potential.

CONCLUSION

Patients with enhanced ventricular repolarization variation computed in terms of the proposed indices were successfully associated to a higher SCD incidence in our study population, evidencing their prognostic value.

SIGNIFICANCE

using a simple ambulatory ECG recording, it is possible to stratify AF patients at risk of SCD, which may help cardiologists in adopting most effective therapeutic strategies, with a positive impact in both the patient and healthcare systems.

A biomarker-based risk score to predict death in patients with atrial fibrillation: the ABC (age, biomarkers, clinical history) death risk score

Aims

In atrial fibrillation (AF), mortality remains high despite effective anticoagulation. A model predicting the risk of death in these patients is currently not available. We developed and validated a risk score for death in anticoagulated patients with AF including both clinical information and biomarkers.

Methods and results

The new risk score was developed and internally validated in 14 611 patients with AF randomized to apixaban vs. warfarin for a median of 1.9 years. External validation was performed in 8548 patients with AF randomized to dabigatran vs. warfarin for 2.0 years. Biomarker samples were obtained at study entry. Variables significantly contributing to the prediction of all-cause mortality were assessed by Cox-regression. Each variable obtained a weight proportional to the model coefficients. There were 1047 all-cause deaths in the derivation and 594 in the validation cohort. The most important predictors of death were N-terminal pro B-type natriuretic peptide, troponin-T, growth differentiation factor-15, age, and heart failure, and these were included in the ABC (Age, Biomarkers, Clinical history)-death risk score. The score was well-calibrated and yielded higher c-indices than a model based on all clinical variables in both the derivation (0.74 vs. 0.68) and validation cohorts (0.74 vs. 0.67). The reduction in mortality with apixaban was most pronounced in patients with a high ABC-death score.

Conclusion

A new biomarker-based score for predicting risk of death in anticoagulated AF patients was developed, internally and externally validated, and well-calibrated in two large cohorts. The ABC-death risk score performed well and may contribute to overall risk assessment in AF.

ClinicalTrials.gov identifier

NCT00412984 and NCT00262600.

Predictors of sudden cardiac death in atrial fibrillation: The Atherosclerosis Risk in Communities (ARIC) study

We previously reported that incident atrial fibrillation (AF) is associated with an increased risk of sudden cardiac death (SCD) in the general population. We now aimed to identify predictors of SCD in persons with AF from the Atherosclerosis Risk in Communities (ARIC) study, a community-based cohort study. We included all participants who attended visit 1 (1987-89) and had no prior AF (n = 14,836). Incident AF was identified from study electrocardiograms and hospitalization discharge codes through 2012. SCD was physician-adjudicated. We used cause-specific Cox proportional hazards models, followed by stepwise selection (backwards elimination, removing all variables with p>0.10) to identify predictors of SCD in participants with AF. AF occurred in 2321 (15.6%) participants (age 45-64 years, 58% male, 18% black). Over a median of 3.3 years, SCD occurred in 110 of those with AF (4.7%). Predictors of SCD in AF included higher age, body mass index (BMI), coronary heart disease, hypertension, diabetes, current smoker, left ventricular hypertrophy, increased heart rate, and decreased albumin. Predictors associated only with SCD and not other cardiovascular (CV) death included increased BMI (HR per 5-unit increase, 1.15, 95% CI, 0.97-1.36, p = 0.10), increased heart rate (HR per SD increase, 1.18, 95% CI 0.99-1.41, p = 0.07), and low albumin (HR per SD decrease 1.23, 95% CI 1.02-1.48, p = 0.03). In the ARIC study, predictors of SCD in AF that are not associated with non-sudden CV death included increased BMI, increased heart rate, and low albumin. Further research to confirm these findings in larger community-based cohorts and to elucidate the underlying mechanisms to facilitate prevention is warranted.

Digoxin Use and Subsequent Clinical Outcomes in Patients With Atrial Fibrillation With or Without Heart Failure in the ENGAGE AF-TIMI 48 Trial

BACKGROUND

Digoxin is widely used in patients with atrial fibrillation despite the lack of randomized controlled trials. Observational studies report conflicting results regarding its association with mortality, perhaps because of residual confounding by the presence of heart failure (HF).

METHODS AND RESULTS

In the ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) trial, clinical outcomes of patients with atrial fibrillation with and without HF were examined by baseline digoxin use during a median follow-up of 2.8 years. HF was defined at baseline as prior or current clinical stage C or D HF. Of 21 105 patients enrolled, 6327 (30%) were treated with digoxin at baseline. Among patients without HF (n=8981), digoxin use (20%) was independently associated with sudden cardiac death (adjusted hazard ratio, 1.51; 95% CI, 1.10-2.08), with no significant interaction by age, sex, left ventricular ejection fraction, renal function, or concomitant medications (P>0.05 for each). Consistent results were observed using propensity matching (adjusted hazard ratio for sudden cardiac death, 1.90; 95% CI, 1.36-2.65). Among patients with HF (n=12 124), digoxin use (37%) was associated with an increase in all-cause death, cardiovascular death, sudden cardiac death, and death caused by HF/cardiogenic shock (P<0.01 for each), but not with noncardiovascular death, stroke/systemic embolism, or myocardial infarction.

CONCLUSIONS

In this observational analysis of patients with atrial fibrillation without investigator-reported HF, digoxin use was significantly associated with sudden cardiac death. While residual confounding cannot be excluded, the association between digoxin use and worse clinical outcomes highlights the need to examine digoxin use, particularly when prescribed to control heart rate in patients with atrial fibrillation in a randomized trial.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00781391.