Atrial fibrillation and obesity among older Chinese: The Guangzhou Biobank Cohort Study

Association of insulin resistance and glycemic measures with major abnormal electrocardiogram in older Chinese: Cross-sectional analysis based on the Guangzhou Biobank Cohort study

AIMS

To examine whether insulin resistance (IR) and glycemic measures were associated with major abnormal electrocardiogram (MA-ECG) and its specific abnormalities in the general population.

METHODS

Twelve-lead ECG measurements were performed on 21,720 participants without cardiovascular disease (5,918 men) from the Guangzhou Biobank Cohort Study. The participants were aged 50 years or above (mean age 61.6, standard deviation 7.1 years). Logistic regression was used to assess the associations of IR and glycemic measures with MA-ECG and specific abnormalities.

RESULTS

Ln-fasting insulin was significantly associated with MA-ECG and ST-T abnormalities (adjusted odds ratio = 1.52, 95 % confidence interval = 1.15-2.02 and 1.83, 1.37-2.45, respectively, for per standard deviation), which were stronger than those of TyG index with MA-ECG (1.08, 1.04-1.13) and ST-T abnormalities (1.16, 1.11-1.22). Ln-fasting insulin had association with Q wave abnormalities (3.19, 1.52-6.67). The association of TyG index with prolonged QTc varied by sex and obesity (P for interaction ≤ 0.01). Participants with diabetes had stronger associations of ln-fasting plasma glucose with ECG abnormalities than those without.

CONCLUSIONS

IR and glycemic measures were associated with MA-ECG, ischemia and prolonged QTc in older Chinese, especially in women, those with obesity, and those with diabetes. These findings underscore the importance of regular evaluations for these groups.

Generalisability of and lessons learned from a mixed-methods study conducted in three low- and middle-income countries to identify care pathways for atrial fibrillation

BACKGROUND

Identifying existing care pathways is the first step for understanding how services can be improved to enable early diagnosis and effective follow-up care for non-communicable diseases (NCDs); however, evidence on how care pathways can and should be identified in low- and middle-income countries (LMICs) is lacking.

OBJECTIVE

To describe generalisability and lessons learned from recruitment and data collection for the quantitative component of a mixed methods study designed to determine the care pathway for atrial fibrillation (AF) in Brazil, China and Sri Lanka.

METHODS

Adults (≥18 years) that spoke the local language and with an AF diagnosis were eligible. We excluded anyone with a hearing or cognitive impairment or ineligible address. Eligible participants were identified using electronic records in Brazil and China; in Sri Lanka, researchers attended the outpatient clinics to identify eligible participants. Data were collected using two quantitative questionnaires administered at least 2-months apart. A minimum sample size of 238 was required for each country.

RESULTS

The required sample size was met in Brazil (n = 267) and China (n = 298), but a large proportion of AF patients could not be contacted (47% and 27%, respectively) or refused to participate (36% and 38%, respectively). In Sri Lanka, recruitment was challenging, resulting in a reduced sample (n = 151). Mean age of participants from Brazil, China and Sri Lanka was 69 (SD = 11.3), 65 (SD = 12.8) and 58 (SD = 11.7), respectively. Females accounted for 49% of the Brazil sample, 62% in China and 70% in Sri Lanka.

CONCLUSIONS

Generalisability was an issue in Brazil and China, as was selection bias. Recruitment bias was highlighted in Sri Lanka. Additional or alternative recruitment methods may be required to ensure generalisability and reduce bias in future studies aimed at identifying NCD care pathways in LMICs.

Obesity and Metabolic Syndrome in Atrial Fibrillation: Cardiac and Noncardiac Adipose Tissue in Atrial Fibrillation

Obesity and metabolic syndrome are both associated with atrial fibrillation (AF). Recent research has revealed new insights into the effects of cardiac and noncardiac adipose tissue in mediating these associations. Cardiac adipose tissue, such as epicardial fat, is a powerful predictor of AF and leads to myocardial fatty infiltration and adipokine-induced fibrosis. Increases in noncardiac adipose tissue cause deleterious metabolic, neurohormonal, hemodynamic, and structural changes. Weight loss leads to a regression of adiposity-related fibrosis, structural abnormalities, conduction abnormalities, and reduction in AF burden. As a result, weight loss and risk factor treatment is now an established pillar of AF management.

Atrial fibrillation in low- and middle-income countries: a narrative review

Preventing premature non-communicable disease mortality necessitates a thorough review of one of the most important risk factors for stroke, which is atrial fibrillation (AF). The latter and AF-related stroke are still considered to be problems of high-income countries and are frequently overlooked in low- and middle-income countries (LMICs). In this narrative review, we provide an overview of studies that evaluated at least one of the following determinants of AF burden in LMICs: current epidemiology and trends, stroke prevention, health outcomes, and economic burden. Studies focusing on samples close to the general population (including community- and primary care-based samples) indicate sex-specific prevalence rates up to 7.4% in LMICs. Although AF prevalence is still higher in high-income countries than LMICs, the gap in AF burden between these two groups has been reducing in the past three decades. Oral anticoagulant (OAC) therapy for stroke prevention is underused in LMICs, and there are little data on OAC therapy in relation to stroke risk scores, such as CHA2DS2-VASc. Available data also points to higher morbidity and mortality for patient with AF in LMICs than their counterparts in high-income countries. Data on the consequent economic burden in LMICs is scarce, but it is reasonable to consider it will follow the same trend as that observed for health outcomes. Raising the visibility of AF as a public health problem in LMICs is necessary as a first step to providing adequate care for patients with this condition.

Age-Specific Association Between Body Mass Index and the Incidence of Atrial Fibrillation in Japanese Men

Background: Obesity is reportedly associated with the incidence of atrial fibrillation (AF), but the patterns of age-specific associations between body mass index (BMI) and the risk of AF are unknown.

Methods and Results: We analyzed 10,921 Japanese men without AF from a cohort of employees undergoing annual health examinations. During a follow-up period of 5.0±3.8 years, the incidence of AF was 118 (2.18/1,000 person-years). Using a multivariable Cox regression analysis, high BMI was associated with a risk of AF (hazard ratio; 1.07 by 1 unit change of BMI, 95% confidence interval [CI] 1.00–1.13, P=0.05) overall, and the effect of BMI on AF incidence changed with age (P for interaction=0.08); with subjects aged <65 years with BMI <25 as the reference, HR 0.74 (95% CI 0.47–1.17) in subjects aged <65 years with BMI ≥25, HR 2.98 (95% CI 1.36–6.54) in subjects aged ≥65 years with BMI <25, and HR 6.50 (95% CI 2.58–16.38) in subjects aged ≥65 years with BMI ≥25. The 5-year probability of AF incidence in subjects aged <65 years was 0.87% with BMI <25 and 0.64% in those with BMI ≥25, and in subjects aged ≥65 years it was 2.58% with BMI <25 and 5.53% with BMI ≥25.

Conclusions: Our results indicated that the effect of BMI on AF incidence changes with age among Japanese men. Both physicians and cardiologists need to integrate advice on lifestyle measures, particularly for elderly obese men, into their daily medical routine.

Obesity and atrial fibrillation: making inroads through fat

The global prevalence of obesity has reached epidemic proportions, paralleled by a rise in cases of atrial fibrillation (AF). Data from epidemiological cohorts support the role of obesity as an independent risk factor for AF. Increasing evidence indicates that obesity may contribute to the AF substrate through a number of pathways including by altering epicardial adipose tissue biology, inflammatory pathways, structural cardiac remodelling, and inducing atrial fibrosis. Due to changes in pharmacokinetics and pharmacodynamics, specific therapeutic considerations are required to guide management of patients with AF including anticoagulation and rhythm control. Also, weight loss in patients with AF has been associated with reduced progression from paroxysmal to persistent AF and indeed regression from persistent to proximal AF. However, the role of dietary intervention in AF control remains to be fully elucidated and hard prospective outcome data to support weight loss are required in AF to determine its role as part of a comprehensive risk factor management strategy for AF in obese patients.

Modelling projections for the risks related with atrial fibrillation in East Asia: a focus on ischaemic stroke and death

Aims

In the Far East, there has generally been low uptake of oral anticoagulants (OACs) using vitamin K antagonists (VKA, e.g. warfarin) for stroke prevention in atrial fibrillation (AF), but OAC use has been increasing more recently, with the introduction of the non-vitamin K antagonist oral anticoagulants (NOACs). To explore the risks of ischaemic stroke (IS) and death related to AF in East Asia using modelling projections.

Methods and results

We performed a modelling analysis of possible trends of IS and death rates in AF patients from the time period of only VKA use to current increasing trends of NOAC use projecting until 2050 in East Asia. Data from published articles on the prevalence of AF, IS, and death were used to model estimated event rates. In 2030, the estimated AF population in East Asia will be 608 100, with the use of NOACs leading to a reduction of 82 259 ISs and 16 917 deaths. There was an estimated annual risk reduction of 5484 ISs and 1128 deaths from 2016 to 2030, respectively. The AF population is estimated to reach 861 900 in 2050, with a reduction of 206 315 ISs and 139 353 deaths.

Conclusion

This modelling analysis suggests that the transition from VKA to NOACs may greatly help in reducing the burden of IS and death caused by AF in the East Asian region.

Life's Simple 7 Approach to Atrial Fibrillation Prevention

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice. It constitutes a major public health problem, with total related annual expenses estimated at $6.65 billion. The American Heart Association developed Life's Simple 7 (LS7) to define and monitor ideal cardiovascular health (CVH). In this review, we examine the role of individual components of LS7 to provide further insight regarding potential influence of achieving AHA's strategic goal on AF prevention. While significant advances have been made in the secondary prevention of AF, little progress has been made to prevent the first occurrence of this arrhythmia in at-risk patients. Improvement of overall cardiovascular health as defined by LS7 may substantially reduce AF risk.

Body Mass Index Variability and Long-term Risk of New-Onset Atrial Fibrillation in the General Population: A Korean Nationwide Cohort Study

OBJECTIVE

To assess the effects of body mass index (BMI) variability on the incidence of new-onset atrial fibrillation (AF), stroke, cardiovascular (CV) risk factors, and CV outcomes in a general Asian population.

PATIENTS AND METHODS

Data from the National Health Insurance Service-Health Screening cohort in Korea were used: 171,324 patients without AF were included, and BMI measurements occurred biennially from January 1, 2002, through December 31, 2009. Patient outcomes were followed through 2013. The BMI intraindividual variability between visits was measured.

RESULTS

During mean ± SD follow-up of 47.4±3.9 months, 1959 patients (1.1%) developed new-onset AF. Overweight or obesity (BMI ≥25) had a greater risk of new-onset AF compared with BMI of 20 to 22.5, with a hazard ratio (HR) of 1.24 (95% CI, 1.10-1.41; P<.001). In underweight or normal-weight participants (initial BMI <25), a 1-kg/m² increase of BMI variability increased the risk of new-onset AF, with an adjusted HR (aHR) of 1.13 (95% CI, 1.01-1.25; P=.02). Weight gain increased the risk of new-onset AF (aHR, 1.32; 95% CI, 1.01-1.71; P=.04) and myocardial infarction (aHR, 1.52; 95% CI, 1.06-2.18; P=.02) but not stroke. In this group, blood pressure, glucose level, and total cholesterol level were higher in individuals with the greatest BMI variability compared with those with stable BMI.

CONCLUSION

In the underweight and normal-weight Asian population, BMI variability, especially weight gain, was related to increased risk of new-onset AF and myocardial infarction. Avoiding weight gain is important to improve CV outcomes.

Epidemiological Characteristics of Atrial Fibrillation in Southern China: Results from the Guangzhou Heart Study

Precise prevalence of atrial fibrillation (AF) and the associated risk factors in southern China are rarely reported. This large population-based follow-up study, the Guangzhou Heart Study, was conducted from 2015 to 2017 to fill up this gap. Permanent residents aged 35 years and above in Guangzhou city were enrolled and demographic factors of participants were collected by a structured questionnaire. Examinations of physical, electrocardiographic and biochemical indicators were performed following a standard operation procedure designed prior to the field investigation. Descriptive statistics were used to evaluate basic characteristics of the study participants, and multivariate logistic regression model was performed to assess the AF prevalence-related factors. The detailed study design, the baseline characteristics and the prevalence of AF were reported here. In total, 12,013 residents were enrolled, and the percentage of participants from rural and urban areas was 53.92% and 46.08%, respectively. In total, 90.57% participants aged 40-79 years old and the proportion of women was more than men (64.98% vs. 35.02%). Overall, the prevalence of AF among the participants was 1.46%. Increasing age, male sex and widowed marital status were associated with higher AF prevalence (P-value < 0.05). The prevalence of AF increased with age and climbed to approximately 5% in residents aged 80 years and over. Residents with abnormal higher blood level of total cholesterol tended to have a lower AF prevalence but a higher prevalence of AF was observed in female participants with lower level of high density lipoprotein cholesterol land higher level uric acid (all P-value < 0.05). Personal illness such as hypertension, diabetes mellitus, dyslipidemia, myocardial infarction, heart failure, stroke and transient ischemic were significantly linked to the attack of AF (all P-value < 0.05). This study will be rich resource for investigating environmental exposure and individual genetic diathesis of AF and other common cardiovascular diseases in Chinese population.

Optimal Thromboprophylaxis in Elderly Chinese Patients with Atrial Fibrillation (ChiOTEAF) registry: protocol for a prospective, observational nationwide cohort study

INTRODUCTION

Atrial fibrillation (AF) is a worldwide healthcare burden that is associated with the ageing population. Elderly patients with AF with multiple comorbidities usually present with a high risk of thromboembolism and bleeding. Limited prospective data are available from Asian cohorts on the epidemiology and complications of AF. The present prospective cohort study aims to explore contemporary antithrombotic strategies among the elderly Chinese population in the new era of non-vitamin K antagonist oral anticoagulants and to compare the clinical characteristics and outcomes between Chinese and European AF populations.

METHODS AND ANALYSIS

The Optimal Thromboprophylaxis in Elderly Chinese Patients with Atrial Fibrillation (ChiOTEAF) registry will recruit 5000 patients with AF over 65 years of age in China. AF-related risks, including stroke/systemic thromboembolism and bleeding outcomes, will be assessed. Medical history, risk factors, demographic information and management will be collected at baseline, and clinical events during 1 year follow-up will be recorded. Follow-up will be conducted for at least 1 year and then annually thereafter. As our registry has a common protocol to the European Society of Cardiology EURObservational Research Programme AF general registry programme, preplanned analyses comparing the clinical profiles and outcomes will be performed. The ChiOTEAF registry offers an opportunity to provide a better understanding of the clinical profiles and adverse outcomes of patients with AF in China and allow for comparisons with a contemporary European population.

ETHICS AND DISSEMINATION

Ethics approval was granted by the Central Medical Ethic Committee of Chinese PLA General Hospital (approval no S2014-065-01). The (inter)national research presentations, peer-reviewed publications and media coverage of the research will be sued for dissemination of the results.

Survey of Antithrombotic Treatment in Rural Patients (>60 years) with Atrial Fibrillation in East China

The prevalence and antithrombotic treatment of atrial fibrillation (AF) in Chinese rural population is not well known. The aim of this study was to investigate the extent to which antithrombotic treatment was prescribed for rural AF patients >60 years. We identified 828 AF patients from 36734 rural residents >60 years in Shanghai China. Our data indicated the overall prevalence rate of AF was 2.3% in rural population >60 years in East China and 38.9% of AF patients underwent antithrombotic therapy, including warfarin (5.9%), aspirin (29.6%), clopidogrel (2.9%) and aspirin combined with clopidogrel (0.5%). Of enrolled subjects, 98.4% had CHA₂DS₂-VASc score ≥1, 72.0% had HAS-BLED score <3 and 59.2% had CHA₂DS₂-VASc score ≥2 with HAS-BLED score <3. Missing early detection (34.9%), delay in seeking treatment for asymptomatic AF (25.5%) and doctors’s incomplete inform of AF-related risk of stroke to patients (21.7%) were three dominant causes for failing anticoagulant usage. In conclusion, most AF patients were with a high risk of thrombosis and a low risk of bleeding in China, but a large majority of them failed to take anticoagulants mainly for missing an early screening of AF and lack of awareness on AF for both patients and primary care physicians.

Risk Factor Management in Atrial Fibrillation

Atrial fibrillation (AF) is the most common clinical arrhythmia and is associated with increased morbidity and mortality. There is growing evidence that numerous cardiovascular diseases and risk factors are associated with incident AF and that lone AF is rare. Beyond oral anticoagulant therapy, rate and rhythm control, therapy targeting risk factors and underlying conditions is an emerging AF management strategy that warrants better implementation in clinical practice. This review describes current evidence regarding the association between known modifiable risk factors and underlying conditions and the development and progression of AF. It discusses evidence for the early management of underlying conditions to improve AF outcomes. It also provides perspective on the implementation of tailored AF management in daily clinical practice.

Anthropometric parameters and the incidence of atrial fibrillation in older people: the PRO.V.A study

BACKGROUND

Atrial fibrillation (AF) has been associated with body size and central obesity, but the impact of different anthropometric measures in this relationship has been inadequately investigated.

HYPOTHESIS

In this study, we examined the association between baseline anthropometric parameters with the incidence of AF in older people, hypothesizing that body size could impact the onset of AF more than fat distribution.

METHODS

Our study included 1764 participants with a mean age of 74.3 ± 6.9 years and no AF at baseline. Body mass index (BMI), body height, body surface area (BSA), waist and hip circumference, waist-to-stature ratio, waist-to-hip ratio, and mid-upper arm circumference (MUAC) were measured by trained physicians. AF was assessed after a 4.4-year follow-up.

RESULTS

There were 115 new cases of AF observed after the follow-up. Taking lower values of these measures for reference, the adjusted AF risk was 2.42 (95% confidence interval [CI]:1.88-3.12) for the highest stature quartile, 1.36 (95% CI:1.15-1.62) for BMI ≥30 kg/m2 , 2.12 (95% CI:1.73-2.59) for the highest BSA quartile, 1.38 (95% CI: 1.21-1.56) for higher MUAC, and 1.39 (95% CI: 1.23-1.58, P < 0.0001) for higher hip circumference values. Central obesity did not seem to relevantly predict the onset of AF in our sample. Stature revealed the strongest impact on the onset of AF (5% higher risk of developing AF per 1 cm increase in height).

CONCLUSIONS

Body size, particularly tall stature and obesity, but not fat distribution, seems to be associated with the risk of AF in the elderly.

Epidemiology of Atrial Fibrillation: The Australian and Asia-Pacific Perspective

The epidemic of atrial fibrillation (AF) is increasingly recognised as a growing health problem worldwide. Although epidemiological studies on AF in the Asia-Pacific region are scarce, given the increasing age and size of populations in this region, the burden of AF is expected to be far greater than in North America and Europe. This is not only due to the growing, ageing population but also an increased incidence of risk factors for AF, such as hypertension, obesity, metabolic syndrome and diabetes, in the Asia-Pacific region. While further, high quality data on such aspects as risk factors, racial disparities and clinical implications is urgently required, there is an immediate need for increased focus on appropriate stroke prophylaxis and risk factor management to minimise the clinical complications and societal burden of AF.

Associations of Epicardial, Abdominal, and Overall Adiposity With Atrial Fibrillation

Background—

Although adiposity is increasingly recognized as a risk factor for atrial fibrillation (AF), the importance of epicardial fat compared with other adipose tissue depots remains uncertain. We sought to characterize and compare the associations of AF with epicardial fat and measures of abdominal and overall adiposity.

Methods and Results—

We conducted a meta-analysis of 63 observational studies including 352 275 individuals, comparing AF risk for 1-SD increases in epicardial fat, waist circumference, waist/hip ratio, and body mass index. A 1-SD higher epicardial fat volume was associated with a 2.6-fold higher odds of AF (odds ratio, 2.61; 95% confidence interval [CI], 1.89–3.60), 2.1-fold higher odds of paroxysmal AF (odds ratio, 2.14; 95% CI, 1.45–3.16) and, 5.4-fold higher odds of persistent AF (odds ratio, 5.43; 95% CI, 3.24–9.12) compared with sinus rhythm. Likewise, a 1-SD higher epicardial fat volume was associated with 2.2-fold higher odds of persistent compared with paroxysmal AF (odds ratio, 2.19; 95% CI, 1.66–2.88). Similar associations existed for postablation, postoperative, and postcardioversion AF. In contrast, associations of abdominal and overall adiposity with AF were less extreme, with relative risks per 1-SD higher values of 1.32 (95% CI, 1.25–1.41) for waist circumference, 1.11 (95% CI, 1.08–1.14) for waist/hip ratio, and 1.22 (95% CI, 1.17–1.27) for body mass index.

Conclusions—

Strong and graded associations were observed between increasing epicardial fat and AF. Moreover, the strength of associations of AF with epicardial fat is greater than for measures of abdominal or overall adiposity. Further studies are needed to assess the mechanisms and clinical relevance of epicardial fat.

Prevalence of atrial fibrillation in the Malaysian communities

BACKGROUND AND AIM

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. The REDISCOVER (Responding to Increasing Cardiovascular disease prevalence) study is an observational longitudinal community-based study that tracks changing lifestyles, risk factors and chronic disease in urban and rural areas of Malaysia. In this study, we aim to study the prevalence of AF and its associated risk factors.

METHODS

The study was conducted between 2007 and 2014. Participants were required to complete questionnaires on cardiovascular risk factors and medical history, and undergo physical examinations, blood tests, ECG and echocardiography examinations. Demographic variables including weight, height, blood pressure, serum glucose and serum lipid were recorded. Participants with AF were identified from their baseline ECG and at 3-year follow up.

RESULTS

A total of 10 805 subjects participated in the study. Mean age was 52.6(±11.6) years and 56% were female; 4.4% of subjects had a diagnosis of ischaemic heart disease, 1.3% had a previous stroke, 16.7% had diabetes mellitus and 45.6% had hypertension. There were 53 subjects diagnosed with AF at baseline, giving a prevalence of 0.49%, and 0.54% at 3 years. AF was more prevalent in males (58.5% in the AF group compared to 43.9% in sinus rhythm (SR) subjects; p=0.03) and the older age group. Ischaemic heart disease was more prevalent in AF subjects (22.6%) compared to SR subjects (4.4%) (p<0.001). In the AF group previous stroke had occurred in 1.9% of subjects compared to 1.3% in the SR population (p=0.51), and 24.5% of subjects in the AF group had diabetes compared to 16.6% in the SR group (p=0.12). There was a significant difference in the prevalence of hypertension between the AF group (59.6%) compared to the SR subjects (45.5%) (p=0.04).

CONCLUSIONS

The prevalence of AF in the Malaysian population was low at 0.54% compared to the global average of 1%. We found that AF was associated with older age, male sex, hypertension, and ischaemic heart disease.

Prevalence and associating factors of atrial fibrillation in patients with hypertension: a nation-wide study

Background

Atrial fibrillation (AF) is a common cardiac arrhythmia and increases risk of ischemic stroke. Data on the prevalence of AF in Thailand is lacking especially in patients with hypertension. The objectives of this study were to determine prevalence of AF in patients with hypertension and to determine factors that are associated with increased prevalence of AF in a multicenter nationwide study.

Methods

A cross-sectional survey for the national outcome evaluation among hypertensive patients visiting 831 public hospitals in Thailand was conducted between 2011 and 2012 to evaluate status of standard care in hypertensive patients visiting public Thailand Ministry of Public Health (MoPH) hospitals. Inclusion criteria were hypertensive patients aged at least 20 years who had received medical care in the targeted hospital for at least 12 months. The main outcome measurement was AF rhythm, and was measured along with potential risk factors age, gender and cardiovascular risk factors.

Results

There were 13207 hypertensive patients who had ECG data recorded during the survey. AF was detected in 457 patients (3.46 %). Prevalence of AF increased with increasing age, was more common in males and in patients with chronic kidney disease (CKD). Multivariable modelling was conducted to assess which factors were most associated with increased prevalence of AF, and the results showed older age followed by male gender, low LDL-cholesterol and increased uric acid levels were the most important risk factors for AF in this population.

Conclusions

Prevalence of AF in hypertensive patients was 3.46 %. Factors associated with increased risk of AF are old age, male gender, low LDL-cholesterol and elevated uric acid level.

Evaluation of Moderate Alcohol Use With QT Interval and Heart Rate Using Mendelian Randomization Analysis Among Older Southern Chinese Men in the Guangzhou Biobank Cohort Study

Western observational studies show that moderate alcohol use is associated with lower cardiovascular disease (CVD) risk, but these associations may be confounded by the healthier attributes of moderate users in these settings. Mendelian randomization analysis may help to ascertain the causal effect of moderate alcohol use on specific factors related to CVD and thereby clarify the role of alcohol. We used Mendelian randomization analysis with the aldehyde dehydrogenase 2 gene (ALDH2) as an instrumental variable to examine the association of alcohol units (10 g of ethanol) per day with heart rate-corrected QT interval and heart rate assessed from electrocardiogram among 4,588 older southern Chinese men in the Guangzhou Biobank Cohort Study (2003-2008). The F statistic was 77 for ALDH2 on alcohol use, suggesting little weak-instrument bias. Instrumental variable analysis showed that alcohol units were not associated with the corrected QT interval, with β = 1.04 (95% confidence interval: -0.61, 2.70) milliseconds, but they were associated with increased heart rate, with β = 0.98 (95% confidence interval: 0.04, 1.92) beat per minute. This study suggests that moderate alcohol use in men is not beneficial for heart function via QT interval or heart rate but could be detrimental. Future studies using specific cardiovascular outcomes may elucidate how alcohol affects different aspects of the cardiovascular system and, hence, the overall effects of alcohol on CVD can be estimated.

The prevalence, incidence, management and risks of atrial fibrillation in an elderly Chinese population: a prospective study

Background

There is limited information on prevalent and incident atrial fibrillation in Chinese. We aimed to investigate the prevalence, incidence, management and risks of atrial fibrillation in an elderly Chinese population.

Methods

In a population—based prospective study in elderly (≥60 years) Chinese, we performed cardiovascular health examinations including a 12-lead electrocardiogram at baseline in 3,922 participants and biennially during follow-up in 2,017 participants. We collected information on vital status during the whole follow-up period.

Results

The baseline prevalence of atrial fibrillation was 2.0 % (n = 34) in 1718 men and 1.6 % (n = 36) in 2204 women. During a median 3.8 years of follow-up, the incidence rate of atrial fibrillation (n = 34) was 4.9 per 1000 person-years (95 % confidence interval [CI], 3.4–6.9). In univariate analysis, both the prevalence and incidence of atrial fibrillation were higher with age advancing (P < 0.0001) and in the presence of coronary heart disease (P ≤ 0.02). Of the 104 prevalent and incident cases of atrial fibrillation, only 1 (1.0 %) received anticoagulant therapy (warfarin). These patients with atrial fibrillation, compared with those with sinus rhythm, had significantly higher risks of all-cause (n = 261, hazard ratio [HR] 1.87, 95 % CI, 1.09–3.20, P = 0.02), cardiovascular (n = 136, HR 3.78, 95 % CI 2.17–6.58, P < 0.0001) and stroke mortality (n = 44, HR 6.31, 95 % CI 2.81–14.19, P = 0.0003).

Conclusions

Atrial fibrillation was relatively frequent in elderly Chinese, poorly managed and associated with higher risks of mortality.

Prevalence, incidence, and lifetime risk of atrial fibrillation in China: new insights into the global burden of atrial fibrillation

BACKGROUND

Much of the epidemiology of atrial fibrillation (AF) is based on data from Western populations. Despite the huge population of Asia, data on the clinical epidemiology of AF in Asian countries are limited. The current study aimed to investigate the prevalence and incidence of newly diagnosed (ie, incident) AF, as well as lifetime risk, in China and to determine the clinical risk factors contributing to its development.

METHODS

Using a medical insurance database involving > 10 million individuals for the years 2001 to 2012 in the southwest of China, trends in incident AF were calculated using Kaplan-Meier analysis and Cox regression. The usefulness of the CHADS2 (congestive heart failure, hypertension, age, diabetes, stroke [doubled]) and CHA2DS2-VASc (congestive heart failure, hypertension, age ≥ 75 [doubled], diabetes, stroke [doubled], vascular disease, age 65-74, and sex category [female]) scores was tested in predicting the occurrence of incident AF.

RESULTS

A total of 471,446 individuals (aged ≥ 20 years) were studied, with 1,924,975 person-years of experience. We identified 921 patients with incident AF (62% male; mean age, 62 years). The prevalence of incident AF in subjects aged ≥ 20 years was 0.2 per 100 people, with an incidence of AF of 0.05 per 100 person-years overall. Over an 11-year period, the prevalence of AF increased 20-fold, whereas AF-related stroke increased 13-fold. The lifetime risk of AF was approximately one in five among Chinese adults, and it increased with advancing age. The CHA2DS2-VASc score was superior to the CHADS2 score in predicting the risk of incident AF in our Chinese population (DeLong test, Z = 6.621, P < .001).

CONCLUSIONS

The AF burden, as well as the risk of AF-related stroke, has increased significantly over the past 11 years in the southwest of China. The public health burden of AF and its complications are greatest in the very elderly, with major implications for health-care systems given the global burden of this common arrhythmia.

Genetic variants related to height and risk of atrial fibrillation: the cardiovascular health study

Increased height is a known independent risk factor for atrial fibrillation (AF). However, whether genetic determinants of height influence risk is uncertain. In this candidate gene study, we examined the association of 209 height-associated single-nucleotide polymorphisms (SNPs) with incident AF in 3,309 persons of European descent from the Cardiovascular Health Study, a prospective cohort study of older adults (aged ≥ 65 years) enrolled in 1989-1990. After a median follow-up period of 13.2 years, 879 participants developed incident AF. The height-associated SNPs together explained approximately 10% of the variation in height (P = 6.0 × 10(-8)). Using an unweighted genetic height score, we found a nonsignificant association with risk of AF (per allele, hazard ratio = 1.01, 95% confidence interval: 1.00, 1.02; P = 0.06). In weighted analyses, we found that genetically predicted height was strongly associated with AF risk (per 10 cm, hazard ratio = 1.30, 95% confidence interval: 1.03, 1.64; P = 0.03). Importantly, for all models, the inclusion of actual height completely attenuated the genetic height effect. Finally, we identified 1 nonsynonymous SNP (rs1046934) that was independently associated with AF and may warrant future study. In conclusion, we found that genetic determinants of height appear to increase the risk of AF, primarily via height itself. This approach of examining SNPs associated with an intermediate phenotype should be considered as a method for identifying novel genetic targets.

Alcohol consumption and electrocardiographic left ventricular hypertrophy and mediation by elevated blood pressure in older Chinese men: the Guangzhou Biobank Cohort Study

BACKGROUND

Chinese people have a markedly lower alcohol consumption than people in the West. Whether alcohol consumption at such levels is associated with left ventricular hypertrophy, and the role of blood pressure (BP) in this relationship is unclear. We investigated the association between alcohol consumption and electrocardiographic left ventricular hypertrophy (ECG-LVH) and the mediating role of BP in Chinese men aged ≥50 years.

METHODS AND RESULTS

A case-control analysis was conducted on baseline cross-sectional data from the community-based Guangzhou Biobank Cohort Study (2003-2008), using standard 12-lead resting electrocardiograms. By comparing 191 new ECG-LVH cases with 4311 controls, excessive drinking (>210 g/week) showed excess risks for ECG-LVH (odds ratio [OR] = 1.90, 95% confidence interval [CI] = 1.12-3.24), after adjusting for education, income, occupation, physical activity, smoking, body mass index, fasting glucose, triglyceride, total cholesterol, high-density lipoprotein cholesterol, BP, and antihypertensive medication. Mediation analysis showed a significant mediating effect of BP on the association between excessive drinking and ECG-LVH: systolic (31%) and diastolic (16%). After multivariate adjustment, no significant association was found between occasional drinking (<once/week: OR = 1.20, 95% CI = 0.80-1.80) and moderate drinking (≥once/week to ≤210 g/week: OR = 0.88, 95% CI = 0.53-1.47) with increased/decreased risk of ECG-LVH.

CONCLUSIONS

Alcohol consumption at >210 g/week in Chinese men is an independent risk factor for ECG-LVH. Low power prevented us from examining whether drinking at <once/week to ≤210 g/week is associated with decreased/increased risk of ECG-LVH. Elevated BP partially mediates between alcohol and ECG-LVH. A Mendelian randomization approach with a large sample size is warranted to determine the relations among alcohol consumption, BP, and LVH.

Body mass index and adverse events in patients with incident atrial fibrillation

BACKGROUND

Obesity is associated with the development of atrial fibrillation and may impact atrial fibrillation-related outcomes. To date, no anthropometric measure is included in any risk stratification scheme for stroke and death in atrial fibrillation patients.

METHODS

The prospective Danish Diet, Cancer and Health study is a cohort including 57,053 participants (27,178 men and 29,875 women) aged between 50 and 64 years. The study population for this study included the 3135 patients (2025 men and 1110 women) who developed incident atrial fibrillation during follow-up.

RESULTS

Of the subjects with atrial fibrillation, 1414 (45%) had a body mass index (BMI) in the overweight category (BMI 25 to <30 kg/m(2)) and 767 (24%) were categorized as obese (BMI ≥30 kg/m(2)). During a median follow-up of 4.9 years, 609 deaths and 216 thromboembolic events (98% ischemic strokes) occurred. Using normal-weight patients as reference, the risk of a composite end point of "ischemic stroke, thromboembolism, or death" was significantly higher in overweight (crude hazard ratio [HR] 1.31; 95% confidence interval [CI], 1.09-1.56) and obese patients (crude HR 1.55; 95% CI 1.27-1.90). After adjustment for CHADS2 and CHA2DS2-VASc scores, the HRs for the composite end point were 1.21 (95% CI 1.02-1.45) and 1.31 (95% CI 1.10-1.56), respectively, for overweight and 1.25 (95% CI 1.03-1.53) and 1.36 (95% CI 1.11-1.65), respectively, for obese. Continuous analyses of BMI stratified by sex identified obese men and normal-weight women as the sex-specific "high-risk" categories.

CONCLUSION

Overweight and obesity are risk factors for "ischemic stroke, thromboembolism or death" in patients with atrial fibrillation, even after adjustment for CHADS2 and CHA2DS2-VASc scores. The association between BMI and outcomes among atrial fibrillation patients may be modified by sex.

The global burden of atrial fibrillation and stroke: a systematic review of the epidemiology of atrial fibrillation in regions outside North America and Europe

BACKGROUND

Although atrial fibrillation (AF) is accepted as the most common sustained cardiac arrhythmia, most published epidemiologic studies focus on predominantly white populations in North America or Europe, and information on AF in nonwhite populations is scarce. The objective of this study was to undertake a systematic review of the published literature on the epidemiology of AF in other regions.

METHODS

Systematic literature searches (MEDLINE; 1990-2010) identified epidemiologic studies reporting on the prevalence or incidence of AF, stroke in AF, risk factors for AF, or the use of antithrombotic therapy in countries outside North America and Europe. This report presents a descriptive analysis of the data; no meta-analysis was planned.

RESULTS

Many of the 38 articles identified were from the Far East, although Australia, New Zealand, the Middle East, and South America were also represented. The reported prevalence of AF varied among countries, with different ranges in community- and hospital-based studies (0.1%-4% and 2.8%-14%, respectively). The use of anticoagulant therapy varied widely among countries and studies, as did the reported prevalence of stroke in patients with AF (2.8%-24.2%).

CONCLUSIONS

High-quality epidemiologic studies are clearly required to improve understanding of the worldwide burden of AF and stroke in AF. Major improvements in the provision of thromboprophylaxis are also needed in many countries, given the high proportion of untreated patients who are, hence, at risk of stroke.

Review of epidemiology and management of atrial fibrillation in developing countries

BACKGROUND

Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia. In developing countries, AF is a growing public health problem with the epidemiologic transition from communicable to non-communicable diseases. However, relatively little is known about AF in the developing world. The aim of this review is to examine in developing countries the prevalence, associated medical conditions and management of AF.

METHODS

A literature search was conducted via MEDLINE and EMBASE (1990-2012).

RESULTS

Seventy studies were included in the review. The prevalence of AF in the general population ranged from 0.03% to 1.25%, while the prevalence of AF in hospital-based studies varied from 0.7% to 55.7%. Prevalence of AF in Africa was lower than in other regions. The most common conditions associated with AF were hypertension (10.3%-71.9%) and valvular heart disease (5.6%-66.3%). The prevalence of stroke in patients with AF ranged from 6.7% to 27%. The utilization of anticoagulants was highly variable (2.7%-72.7%). Approximately half of the patients with AF using warfarin had therapeutic International Normalized Ratios (INR). There was a high prevalence of use of rate control therapies (55.3%-87.3%).

CONCLUSIONS

The limited studies available suggest that in the developing world there is a significant prevalence of AF, which is predominantly associated with hypertension and valvular heart disease, and carries a risk of stroke. Highly variable use of anticoagulants may be related to different health care and socioeconomic settings. More studies are needed to improve understanding of the epidemiology and management of AF in developing countries.

Atrial fibrillation: profile and burden of an evolving epidemic in the 21st century

BACKGROUND

Atrial fibrillation (AF) represents an increasing public health challenge with profound social and economic implications.

METHODS

A comprehensive synthesis and review of the AF literature was performed. Overall, key findings from 182 studies were used to describe the indicative scope and impact of AF from an individual to population perspective.

RESULTS

There are many pathways to AF including advancing age, cardiovascular disease and increased levels of obesity/metabolic disorders. The reported population prevalence of AF ranges from 2.3%-3.4% and historical trends reflect increased AF incidence. Estimated life-time risk of AF is around 1 in 4. Primary care contacts reflect whole population trends: AF-related case-presentations increase from less than 0.5% in those aged 40 years or less to 6-12% for those aged 85 years or more. Globally, AF-related hospitalisations (primary or secondary diagnosis) showed an upward trend (from ~35 to over 100 admissions/10,000 persons) during 1996 to 2006. The estimated cost of AF is greater than 1% of health care expenditure and rising with hospitalisations the largest contributor. For affected individuals, quality of life indices are poor and AF confers an independent 1.5 to 2.0-fold probability of death in the longer-term. AF is also closely linked to ischaemic stroke (3- to 5-fold risk), chronic heart failure (up to 50% develop AF) and acute coronary syndromes (up to 25% develop AF) with consistently worse outcomes reported with concurrent AF. Future projections predict at least a doubling of AF cases by 2050.

SUMMARY

AF represents an evolving, global epidemic providing considerable challenges to minimise its impact from an individual to whole society perspective.

Research on cachexia, sarcopenia and skeletal muscle in cardiology

BACKGROUND

The awareness of cardiac cachexia, i.e. involuntary weight loss in patients with underlying cardiovascular disease, has increased over the last two decades.

METHODS AND RESULTS

This mini-review looks at recent research in the cardiovascular literature that is relevant to the areas of interest of the Journal of Cachexia, Sarcopenia and Muscle. It identifies significant research in the last 3 years on the obesity paradox, the causes and effects of skeletal muscle wasting, animal models of cachexia and emerging treatment ideas in cardiac cachexia.

CONCLUSIONS

Assuming a similar literature in the fields of cancer, chronic obstructive pulmonary disease, chronic renal failure and chronic liver failure, the emergence of cachexia as a vibrant area of clinical and experimental research seems assured.

The impact of height on the risk of atrial fibrillation: the Cardiovascular Health Study

AIMS

Atrial fibrillation (AF) is the most common sustained arrhythmia. Increased body size has been associated with AF, but the relationship is not well understood. In this study, we examined the effect of increased height on the risk of AF and explore potential mediators and implications for clinical practice.

METHODS AND RESULTS

We examined data from 5860 individuals taking part in the Cardiovascular Health Study, a cohort study of older US adults followed for a median of 13.6 (women) and 10.3 years (men). Multivariate linear models and age-stratified Cox proportional hazards and risk models were used, with focus on the effect of height on both prevalent and incident AF. Among 684 (22.6%) and 568 (27.1%) incident cases in women and men, respectively, greater height was significantly associated with AF risk [hazard ratio (HR)(women) per 10 cm 1.32, confidence interval (CI) 1.16-1.50, P < 0.0001; HR(men) per 10 cm 1.26, CI 1.11-1.44, P < 0.0001]. The association was such that the incremental risk from sex was completely attenuated by the inclusion of height (for men, HR 1.48, CI 1.32-1.65, without height, and HR 0.94, CI 0.85-1.20, with height included). Inclusion of height in the Framingham model for incident AF improved discrimination. In sequential models, however, we found minimal attenuation of the risk estimates for AF with adjustment for left ventricular (LV) mass and left atrial (LA) dimension. The associations of LA and LV size measurements with AF risk were weakened when indexed to height.

CONCLUSION

Independent from sex, increased height is significantly associated with the risk of AF.

The utility of collaborative biobanks for cardiovascular research

Differences between animal and human atherosclerosis have led to the requirement for clinical data, imaging information and biological material from large numbers of patients and healthy persons. Where such "biobanks" exist, they have been fruitful sources for genomewide association, diagnostic accuracy, ethnicity, and risk stratification cohort studies. In addition once established, they attract funding for future projects. Biobanks require a network of medical contributors, secure storage facilities, bioinformatics expertise, database managers, and ethical working practices to function optimally. There is the opportunity for collaboration between individual biobanks to further amplify the advantages afforded.