Review of epidemiology and management of atrial fibrillation in developing countries. Int J Cardiol. 2013;167:2412-2420. [PMID: 23453870 DOI: 10.1016/j.ijcard.2013.01.184]

The Cumulative Incidence of Stroke, Myocardial infarction, Heart Failure and Sudden Cardiac Death in Patients with Atrial Fibrillation

Introduction:

Atrial fibrillation represents the most common cardiac arrhythmia in clinical practice. By year 2030, 14–17 million AF patients are anticipated in the European Union. Atrial fibrillation remains one of the major causes of stroke, heart failure, sudden death all over the world.

Research Objectives:

The objective of our study is to determine the cardiac and cerebrovascular events (myocardial infarction, heart failure, stroke, sudden cardiac death) and their cumulative incidence during 11 years follow up period.

Patients and methods:

This study includes 2352 ambulant and hospitalized patients with atrial fibrillation (AF) who were enrolled during the follow up period. All patients underwent clinical evaluation in order to determine cardiac and cerebrovascular events (myocardial infarction, heart failure, stroke, sudden cardiac death) and their cumulative incidence.

Results:

The results of cumulative incidence for sudden cardiac death was 1.71%, for stroke 2.56%, for myocardial infarction 1.20% and for heart failure was 5.73%. In our study the age-adjusted incidence and prevalence of AF are slightly lower in women. The study shows that the risk of death is higher in females than in males with AF.

Conclusion:

Despite good progress in the management of patients with atrial fibrillation (AF), this arrhythmia remains one of the major causes of stroke, heart failure, sudden death. Effective treatment of patients with atrial fibrillation includes not only rate control, rhythm control, and prevention of stroke, but also management of cardiovascular risk factors and concomitant diseases.

The Impact of Risk Factors and Comorbidities on The Incidence of Atrial Fibrillation

INTRODUCTION

Atrial fibrillation (AF) is the most common form of cardiac arrhythmia in clinical practice and its prevalence increases with age. Patients who develop AF also have cardiovascular risk factors, structural heart disease, and comorbidities, all of which can increase mortality. AF causes a significant economic burden with the increasing trend in AF prevalence and hospitalizations.

RESEARCH OBJECTIVES

The objective of our study is to evaluate the impact of the most common known risk factors on the incidence of atrial fibrillation as an important precursor of cardiac and cerebrovascular morbidity and mortality among our patients in Bosnia and Herzegovina during median follow up period (September 2006 - September 2016). The other objective is to estimate the CHA2DS2-VASc score among our patients based on clinical parameters.

PATIENTS AND METHODS

This study includes 2352 ambulant and hospitalized patients with atrial fibrillation. All patients underwent clinical evaluation which includes thorough assessment for potential risk factors and concomitant conditions in order to determine which of them represent the most common among examinees with atrial fibrillation.

RESULTS

The results show that male gender has slightly more incidence of AF. Obesity and overweight with BMI ≥ 27, cigarettes smoking and sedentary life style are almost present in patients with AF. Arterial hypertension, coronary artery disease, diabetes mellitus, chronic obstructive pulmonary disease, chronic renal dysfunction, structural and valvular heart disease and peripheral vascular disease are the most common comorbidities among our patients. The mean CHA2DS2-VASc score was 3.2±1.4 and the mean HAS-BLED score was 2.1±1.2.

CONCLUSION

Atrial fibrillation is the most common sustained cardiac rhythm disorder. The study shows that obesity, alcohol consumption, smoking cigarettes and dyslipidemia can be considered as triggers and predisposing factors for appearance of AF. Arterial hypertension, coronary artery disease, chronic obstructive pulmonary disease, diabetes mellitus, Peripheral vascular disease and chronic kidney disease are playing important role in developing of AF.

Gaps in translation from trials to practice: Non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prevention in atrial fibrillation

Worldwide there is a tremendous need for affordable anticoagulants that do not require monitoring. The advent of the non-warfarin oral anticoagulant drugs represents a major advance for stroke prevention in atrial fibrillation (AF). The objectives of this review are to 1) identify gaps in our current knowledge regarding use of these single target anticoagulant drugs; 2) outline the potential implications of these gaps for clinical practice, and thereby, 3) highlight areas of research to further optimise their use for stroke prevention in AF.

Use of Guidelines for Reducing Stroke Risk in Patients With Nonvalvular Atrial Fibrillation: A Review From a Latin American Perspective

Atrial fibrillation (AF) is a prominent risk factor for stroke and a leading cause of death and disability throughout Latin America. Contemporary evidence-based guidelines for the management of AF and stroke incorporate the use of practical and relatively simple scoring methods to estimate both stroke and bleeding risk, in order to assist in matching patients with appropriate interventions. This review examines consistencies and differences among guidelines for reducing stroke risk in patients with AF, assessing the role of user-friendly scoring methods to determine appropriate patients for anticoagulation and other treatment options. Current options include warfarin and direct oral anticoagulants such as dabigatran, rivaroxaban, apixaban, and edoxaban. These agents have been found to be superior or noninferior to standard vitamin K antagonist anticoagulation in large randomized trials. Potential benefits of these agents mainly include lower ischemic stroke rates, reduced intracranial bleeding, no need for regular monitoring, and fewer drug-drug and drug-food interactions. Expert opinions regarding clinical situations for which data are presently lacking, such as emergency bleeding and stroke in anticoagulated patients, are also provided. Enhanced attention and adherence to evidence-based guidelines are essential components for a strategy to reduce stroke morbidity and mortality across Latin America.

Aging in the Cardiovascular System: Lessons from Hutchinson-Gilford Progeria Syndrome

Aging, the main risk factor for cardiovascular disease (CVD), is becoming progressively more prevalent in our societies. A better understanding of how aging promotes CVD is therefore urgently needed to develop new strategies to reduce disease burden. Atherosclerosis and heart failure contribute significantly to age-associated CVD-related morbimortality. CVD and aging are both accelerated in patients suffering from Hutchinson-Gilford progeria syndrome (HGPS), a rare genetic disorder caused by the prelamin A mutant progerin. Progerin causes extensive atherosclerosis and cardiac electrophysiological alterations that invariably lead to premature aging and death. This review summarizes the main structural and functional alterations to the cardiovascular system during physiological and premature aging and discusses the mechanisms underlying exaggerated CVD and aging induced by prelamin A and progerin. Because both proteins are expressed in normally aging non-HGPS individuals, and most hallmarks of normal aging occur in progeria, research on HGPS can identify mechanisms underlying physiological aging.

Association between KCNE1 G38S gene polymorphism and risk of atrial fibrillation: A PRISMA-compliant meta-analysis

BACKGROUND

Previous case-control studies on association between KCNE1 G38S polymorphism and risk of atrial fibrillation (AF) have been published but because of the conflicting results and small sample size of individual studies, the consolidated result is still controversial.

OBJECTIVES

The aim of this study was to explore the relationship between KCNE1 G38S polymorphism and risk of AF.

METHODS

We performed a comprehensive literature search on PubMed, Embase, OVID, Web of Science, Wan Fang, and CNKI databases up to March 10, 2017 in English and Chinese languages. Two of the authors individually extracted study data and assessed the study quality using Newcastle-Ottawa scale. Odds ratios (ORs) and 95% confidence intervals (CIs) were combined in different genetic models for evaluation using a random-effect model or fixed-effect model according to interstudy heterogeneity.

RESULTS

There were totally 14 independent case-control studies of 2810 patients and 3080 healthy controls included. Significant associations were found between KCNE1 G38S polymorphism and AF in overall population under all genetic models: allelic (OR: 1.34, 95% CI: 1.24-1.45, P < .001), homozygous (OR: 1.90, 95% CI: 1.61-2.24, P < .001), heterozygous (OR: 1.43, 95% CI: 1.21-1.68, P < .001), recessive (OR: 1.42, 95% CI: 1.20-1.69, P < .001), dominant genetic model (OR: 1.62, 95% CI: 1.39-1.89, P < .001). Subgroup analyses indicated similar association in Chinese and white.

CONCLUSIONS

The G38S polymorphism in the KCNE1 gene can significantly increase the risk of AF in both Chinese and white.

The cost of warfarin treatment for stroke prevention in patients with non-valvular atrial fibrillation in Russia from a collective perspective

AIMS

Vitamin K antagonists (VKAs) are used for stroke prevention in patients with non-valvular atrial fibrillation (NVAF), but necessitate regular monitoring of prothrombin time via international normalized ratio (INR) testing. This study explores the economic burden of VKA therapy for Russian patients with NVAF.

METHOD

Cardiologists provided clinical characteristics and healthcare resource use data relating to the patient's first year of treatment. Data were used to quantify direct medical costs (INR testing, consultations, drug costs). The same patients completed a questionnaire providing data on direct non-medical costs (travel/expenses for attendance at VKA appointments) and indirect costs (opportunity cost and reduced work productivity). Mean costs per patient per year are described (US dollars).

RESULTS

Cardiologists (n = 50) provided data on 400 patients (mean age = 63, 47% female), and 351 patients (88%) completed the patient questionnaire. Patients had a mean of nine INR tests. Estimated direct medical costs totaled $151.06, and 18.5% of direct medical costs were attributable to drug costs. Estimated annual direct non-medical costs were $22.89 per patient, and indirect costs were $275.59 per patient.

LIMITATIONS

Included patients had been treated for 12-24 months, so are not fully representative of the broader treatment population.

CONCLUSION

Although VKA drugs costs are relatively low, regular INR testing and consultations drive the economic burden for Russian NVAF patients treated with VKA.

Epidemiology and Management of Atrial Fibrillation and Stroke: Review of Data from Four European Countries

In Europe, 1-3% of the population suffers from atrial fibrillation (AF) and has increased stroke risk. By 2060 a doubling in number of cases and great burden in managing this medical condition are expected. This paper offers an overview of data on epidemiology and management of AF and stroke in four European countries as well as the interconnection between these dimensions. A search index was developed to access multiple scientific and "grey" literatures. Information was prioritised based on strength of evidence and date. Information on country reports was double-checked with national experts. The overall prevalence of AF is consistent across countries. France has the lowest stroke incidence and mortality, followed by Netherland and UK, while Romania has higher rates. GPs or medical specialists are responsible for AF treatment; exception are the special thrombosis services in the Netherlands. Prevention measurements are only present in UK through screening programs. Although international and national guidelines are available, undertreatment is present in all countries. Despite differences in healthcare systems and management of AF, epidemiology is comparable between three of the countries. Romania is an outlier, by being limited in data accessibility. This knowledge can contribute to improved AF care in Europe.

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.

Exercise-based cardiac rehabilitation for adults with atrial fibrillation

BACKGROUND

Exercise-based cardiac rehabilitation may benefit adults with atrial fibrillation or those who had been treated for atrial fibrillation. Atrial fibrillation is caused by multiple micro re-entry circuits within the atrial tissue, which result in chaotic rapid activity in the atria.

OBJECTIVES

To assess the benefits and harms of exercise-based rehabilitation programmes, alone or with another intervention, compared with no-exercise training controls in adults who currently have AF, or have been treated for AF.

SEARCH METHODS

We searched the following electronic databases; CENTRAL and the Database of Abstracts of Reviews of Effectiveness (DARE) in the Cochrane Library, MEDLINE Ovid, Embase Ovid, PsycINFO Ovid, Web of Science Core Collection Thomson Reuters, CINAHL EBSCO, LILACS Bireme, and three clinical trial registers on 14 July 2016. We also checked the bibliographies of relevant systematic reviews identified by the searches. We imposed no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCT) that investigated exercise-based interventions compared with any type of no-exercise control. We included trials that included adults aged 18 years or older with atrial fibrillation, or post-treatment for atrial fibrillation.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data. We assessed the risk of bias using the domains outlined in the Cochrane Handbook for Systematic Reviews of Interventions. We assessed clinical and statistical heterogeneity by visual inspection of the forest plots, and by using standard Chi² and I² statistics. We performed meta-analyses using fixed-effect and random-effects models; we used standardised mean differences where different scales were used for the same outcome. We assessed the risk of random errors with trial sequential analysis (TSA) and used the GRADE methodology to rate the quality of evidence, reporting it in the 'Summary of findings' table.

MAIN RESULTS

We included six RCTs with a total of 421 patients with various types of atrial fibrillation. All trials were conducted between 2006 and 2016, and had short follow-up (eight weeks to six months). Risks of bias ranged from high risk to low risk.The exercise-based programmes in four trials consisted of both aerobic exercise and resistance training, in one trial consisted of Qi-gong (slow and graceful movements), and in another trial, consisted of inspiratory muscle training.For mortality, very low-quality evidence from six trials suggested no clear difference in deaths between the exercise and no-exercise groups (relative risk (RR) 1.00, 95% confidence interval (CI) 0.06 to 15.78; participants = 421; I² = 0%; deaths = 2). Very low-quality evidence from five trials suggested no clear difference between groups for serious adverse events (RR 1.01, 95% CI 0.98 to 1.05; participants = 381; I² = 0%; events = 8). Low-quality evidence from two trials suggested no clear difference in health-related quality of life for the Short Form-36 (SF-36) physical component summary measure (mean difference (MD) 1.96, 95% CI -2.50 to 6.42; participants = 224; I² = 69%), or the SF-36 mental component summary measure (MD 1.99, 95% CI -0.48 to 4.46; participants = 224; I² = 0%). Exercise capacity was assessed by cumulated work, or maximal power (Watt), obtained by cycle ergometer, or by six minute walking test, or ergospirometry testing measuring VO2 peak. We found moderate-quality evidence from two studies that exercise-based rehabilitation increased exercise capacity, measured by VO2 peak, more than no exercise (MD 3.76, 95% CI 1.37 to 6.15; participants = 208; I² = 0%); and very low-quality evidence from four studies that exercise-based rehabilitation increased exercise capacity more than no exercise, measured by the six-minute walking test (MD 75.76, 95% CI 14.00 to 137.53; participants = 272; I² = 85%). When we combined the different assessment tools for exercise capacity, we found very low-quality evidence from six trials that exercise-based rehabilitation increased exercise capacity more than no exercise (standardised mean difference (SMD) 0.86, 95% CI 0.46 to 1.26; participants = 359; I² = 65%). Overall, the quality of the evidence for the outcomes ranged from moderate to very-low.

AUTHORS' CONCLUSIONS

Due to few randomised patients and outcomes, we could not evaluate the real impact of exercise-based cardiac rehabilitation on mortality or serious adverse events. The evidence showed no clinically relevant effect on health-related quality of life. Pooled data showed a positive effect on the surrogate outcome of physical exercise capacity, but due to the low number of patients and the moderate to very low-quality of the underpinning evidence, we could not be certain of the magnitude of the effect. Future high-quality randomised trials are needed to assess the benefits and harms of exercise-based cardiac rehabilitation for adults with atrial fibrillation on patient-relevant outcomes.

Systematic review and network meta-analysis of stroke prevention treatments in patients with atrial fibrillation

Background

In the last 4 years, four novel oral anticoagulants have been developed as alternatives to warfarin and antiplatelet agents for stroke prevention in atrial fibrillation (AF) patients. The objective of this review was to estimate the comparative effectiveness of all antithrombotic treatments for AF patients.

Materials and methods

Data sources were Medline Ovid (1946 to October 2015), Embase Ovid (1980 to October 2015), and the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 9, 2015). Randomized controlled trials of AF patients were selected if they compared at least two of the following: placebo, aspirin, aspirin and clopidogrel combination therapy, adjusted-dose warfarin (target international normalized ratio 2.0–3.0), dabigatran, rivaroxaban, apixaban, and edoxaban. Bayesian network meta-analyses were conducted for outcomes of interest (all stroke, ischemic stroke, myocardial infarction, overall mortality, major bleeding, and intracranial hemorrhage).

Results

Based on 16 randomized controlled trials of 96,826 patients, all oral anticoagulants were more effective than antiplatelet agents at reducing the risk of ischemic stroke and all strokes. Compared to warfarin, dabigatran 150 mg (rate ratio 0.65, 95% credible interval 0.52–0.82) and apixaban (rate ratio 0.82, 95% credible interval 0.69–0.97) reduced the risk of all strokes. Dabigatran 150 mg was also more effective than warfarin at reducing ischemic stroke risk (rate ratio 0.76, 95% credible interval 0.59–0.99). Aspirin, apixaban, dabigatran 110 mg, and edoxaban were associated with less major bleeding than warfarin.

Conclusion

All oral anticoagulants reduce the risk of stroke in AF patients. Some novel oral anticoagulants are associated with a lower stroke and/or major bleeding risk than warfarin. In addition to the safety and effectiveness of drug therapy, as reported in this study, individual treatment recommendations should also consider the patient’s underlying stroke and bleeding risk profile.

Computational fluid dynamics modelling of left valvular heart diseases during atrial fibrillation

BACKGROUND

Although atrial fibrillation (AF), a common arrhythmia, frequently presents in patients with underlying valvular disease, its hemodynamic contributions are not fully understood. The present work aimed to computationally study how physical conditions imposed by pathologic valvular anatomy act on AF hemodynamics.

METHODS

We simulated AF with different severity grades of left-sided valvular diseases and compared the cardiovascular effects that they exert during AF, compared to lone AF. The fluid dynamics model used here has been recently validated for lone AF and relies on a lumped parameterization of the four heart chambers, together with the systemic and pulmonary circulation. The AF modelling involves: (i) irregular, uncorrelated and faster heart rate; (ii) atrial contractility dysfunction. Three different grades of severity (mild, moderate, severe) were analyzed for each of the four valvulopathies (AS, aortic stenosis, MS, mitral stenosis, AR, aortic regurgitation, MR, mitral regurgitation), by varying-through the valve opening angle-the valve area.

RESULTS

Regurgitation was hemodynamically more relevant than stenosis, as the latter led to inefficient cardiac flow, while the former introduced more drastic fluid dynamics variation. Moreover, mitral valvulopathies were more significant than aortic ones. In case of aortic valve diseases, proper mitral functioning damps out changes at atrial and pulmonary levels. In the case of mitral valvulopathy, the mitral valve lost its regulating capability, thus hemodynamic variations almost equally affected regions upstream and downstream of the valve. In particular, the present study revealed that both mitral and aortic regurgitation strongly affect hemodynamics, followed by mitral stenosis, while aortic stenosis has the least impact among the analyzed valvular diseases.

DISCUSSION

The proposed approach can provide new mechanistic insights as to which valvular pathologies merit more aggressive treatment of AF. Present findings, if clinically confirmed, hold the potential to impact AF management (e.g., adoption of a rhythm control strategy) in specific valvular diseases.

Suboptimal Use of Oral Anticoagulants in Atrial Fibrillation: Has the Introduction of Direct Oral Anticoagulants Improved Prescribing Practices?

BACKGROUND AND OBJECTIVES

Atrial fibrillation (AF) and the associated risk of stroke are emerging epidemics throughout the world. Suboptimal use of oral anticoagulants for stroke prevention has been widely reported from observational studies. In recent years, direct oral anticoagulants (DOACs) have been introduced for thromboprophylaxis. We conducted a systematic literature review to evaluate current practices of anticoagulation in AF, pharmacologic features and adoption patterns of DOACs, their impacts on proportion of eligible patients with AF who receive oral anticoagulants, persisting challenges and future prospects for optimal anticoagulation.

LITERATURE SOURCE AND SELECTION CRITERIA

In conducting this review, we considered the results of relevant prospective and retrospective observational studies from real-world practice settings. PubMed (MEDLINE), Scopus (RIS), Google Scholar, EMBASE and Web of Science were used to source relevant literature. There were no date limitations, while language was limited to English. Selection was limited to articles from peer reviewed journals and related to our topic.

RESULTS

Most studies identified in this review indicated suboptimal use of anticoagulants is a persisting challenge despite the availability of DOACs. Underuse of oral anticoagulants is apparent particularly in patients with a high risk of stroke. DOAC adoption trends are quite variable, with slow integration into clinical practice reported in most countries; there has been limited impact to date on prescribing practice.

CONCLUSION

Available data from clinical practice suggest that suboptimal oral anticoagulant use in patients with AF and poor compliance with guidelines still remain commonplace despite transition to a new era of anticoagulation featuring DOACs.

Profile and anticoagulation outcomes of patients on warfarin therapy in an urban hospital in Cape Town, South Africa

BACKGROUND

Warfarin is the most frequently used oral anticoagulant worldwide and it is the oral anticoagulant of choice in South Africa for reducing thrombosis-related morbidity and mortality. However, the safety and efficacy of warfarin therapy depends mainly on careful monitoring and maintenance of the international normalised ratio (INR) within an optimal therapeutic range.

AIM

The aim of this study was to describe the profile and the anticoagulation outcomes of patients on warfarin therapy in a major warfarin clinic in the Western Cape Province of South Africa.

SETTING

Victoria Hospital - a district hospital in Cape Town.

METHODS

A cross sectional review of clinical records of patients on warfarin therapy who attended the INR clinic from 01 January 2014 to 30 June 2014 was done. Data analysis was done with STATA to generate appropriate descriptive data.

RESULTS

Our study showed that atrial fibrillation (AF) was the commonest indication for warfarin use in this study and hypertension was the commonest comorbidity among these patients. Only 48.5% achieved target therapeutic range; 51.5% were out-of-range. There was a significant association between alcohol consumption and poor anticoagulation outcomes (p-value < 0.022). Anticoagulation outcomes were better among the older age groups, male patients and in those with AF. The prevalence of thrombotic events while on warfarin treatment was 2.2%, while prevalence of haemorrhagic events was 14%. Most of the patients with bleeding events were on concurrent use of warfarin and other medications with potential drug interactions.

CONCLUSION

In our study, patients who achieved target therapeutic control were less than the acceptable 60%.

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.

Atrial fibrillation: prevalence in a large database of primary care patients in Brazil

AIMS

Although an increasing prevalence of atrial fibrillation (AF) has been reported worldwide, there are few studies from low- and middle-income countries. Our objective is to assess the prevalence of AF and the associated medical conditions in Brazilian primary care patients.

METHODS AND RESULTS

This is an observational retrospective study. Patients ≥5 years of age from primary care centres of 658 municipalities in Minas Gerais, Brazil, who performed digital electrocardiograms (ECGs) by a public telehealth service in 2011 were assessed. Clinical data were self-reported, and ECGs were interpreted by a team of trained cardiologists using standardized criteria. To assess the relation between clinical characteristics and AF, odds ratios were estimated by logistic regression. A total of 262 685 primary care patients were included, mean (SD) age of 50.3 (19.3) years, 59.6% female. Hypertension was reported in 32.0%, family history of coronary heart disease in 15.0%, diabetes in 5.4%, hyperlipidaemia in 2.8%, Chagas disease in 2.9%, and 7.1% reported current smoking. The prevalence of AF was 1.8% overall: 2.4% in men (ranging from 0.001% from 5-19 years old to 14.6% in nonagenarians) and 1.3% in women (ranging from 0.001% from 5-19 years old to 8.7% in nonagenarians) (P < 0.001). The prevalence of AF increased with advancing age. The comorbidities associated with AF were Chagas disease, previous myocardial infarction, hypertension, and chronic obstructive pulmonary disease. Vitamin K antagonist use was reported by 1.5% of patients.

CONCLUSION

The prevalence and age distribution of AF were similar to studies in high-income countries. The proportion of patients who reported the use of anticoagulants was alarmingly low. Our findings point out the necessity to formulate effective treatment strategies for AF in Brazilian primary care settings.

Atrial fibrillation in Sub-Saharan Africa: epidemiology, unmet needs, and treatment options

Health care in Sub-Saharan Africa is being challenged by a double burden of disease as lifestyle diseases common in the developed world, such as stroke and atrial fibrillation (AF), increase, while, simultaneously, health issues of the developing world in terms of communicable disease persist. The prevalence of AF is lower in Africa than in the developed world but is expected to increase significantly over the next few decades. Patients with AF in Africa tend to be younger and have a higher prevalence of rheumatic valvular heart disease than patients with AF in other regions. Permanent AF is the most prevalent type of AF in Africa, possibly due to the lower use of rhythm control strategies than in the developed world. Mortality rates of patients with AF in Africa are high, due largely to poor health care access and suboptimal therapy. The risk of stroke in AF, which is moderate to high in Africans as in the developed world, contributes to the high mortality rate. Patients with AF in Africa are often undertreated with antithrombotics, as cost and access to monitoring are major barriers. Vitamin K antagonists, including warfarin, are the most commonly available oral anticoagulants, but regular monitoring can be challenging, especially for patients in remote areas. Several non-vitamin K antagonist oral anticoagulants (NOACs) have been approved for use in countries across Sub-Saharan Africa and have the potential to reduce stroke burden. The higher cost of newer agents may be offset by the reduced need for regular monitoring, fixed dosing, and lower risk of intracranial bleeding; NOACs could provide a treatment option for patients in remote areas with limited access to regular monitoring. However, NOACs are not indicated in valvular AF. More work is needed to increase understanding of the epidemiology of AF and stroke, as well as to improve management strategies to reduce the burden of cardiovascular disease predicted for Africa.

Prospective national study of the prevalence, incidence, management and outcome of a large contemporary cohort of patients with incident non-valvular atrial fibrillation

BACKGROUND

There are few studies of atrial fibrillation (AF) outside of North America or Europe. The aim of the present study was to assess the prevalence, incidence, management and outcomes of patients with new atrial fibrillation, in a large contemporary cohort (2004-2012) of adult patients.

METHODS AND RESULTS

The Clalit Health Services (CHS) computerized database of 2 420 000 adults, includes data of community clinic visits, hospital discharge records, medical diagnoses, medications, medical interventions, and laboratory test results. The prevalence of AF on January 1, 2004 was 71 644 (3%). Prevalence and incidence of AF increased with age and was higher in men versus women. During the study period (2004-2012) 98 811 patients developed new non-valvular AF (mean age -72, 50% women, 46% with cardiovascular disease, 6% with prior stroke). The rate of persistent warfarin use (dispensed for >3 months in a calendar year) was low (25.7%) and it increased with increasing stroke risk score. Individual Time in Therapeutic Range (TTR) among warfarin users was 42%. The incidence rate of ischemic stroke and death increased with age. The rate of stroke increased from 2 per 1000 person years in patients with CHA(2)DS(2)_VASC SCORE of 0, to 58 per 1000 person years in those with a score of 9.

CONCLUSIONS

In the present study the prevalence and incidence of AF, stroke, and death were comparable to those reported in Europe and North America. The low use of anticoagulation calls for measures to increase adherence to current treatment recommendations in order to improve outcomes.

A functional polymorphism C-509T in TGFβ-1 promoter contributes to susceptibility and prognosis of lone atrial fibrillation in Chinese population

Transforming growth factor-β1 (TGF-β1) is an important mediator of atrial fibrosis and atrial fibrillation (AF). But the involved genetic mechanism is unknown. Herein, the TGF-β1 C-509 T polymorphism (rs1800469) was genotyped in a case-control study of 840 patients and 845 controls in Chinese population to explore the association between the polymorphism and susceptibility and prognosis of lone AF. As a result, the CT and/or TT genotypes had an increased lone AF risk [adjusted odds ratio (OR) = 1.50 for CT, OR = 3.72 for TT, and OR = 2.15 for CT/TT], compared with the TGF-β1CC genotype. Moreover, patients carrying CT/TT genotypes showed a higher possibility of AF recurrence after catheter ablation, compared with patients carrying CC genotype. In a genotype-phenotype correlation analysis using 24 normal left atrial appendage samples, increasing gradients of atrial TGF-β1 expression levels positively correlated with atrial collagen volume fraction were identified in samples with CC, CT and TT genotypes. The in vitro luciferase assays also showed a higher luciferase activity of the -509 T allele than that of the -509 C allele. In conclusion, the TGF-β1 C-509 T polymorphism is involved in the etiology of lone AF and thus may be a marker for genetic susceptibility to lone AF and predicting prognosis after catheter ablation in Chinese populations. Therefore, we provide new information about treatment strategies and our understanding of TGF-β1 in AF.

The Optimal Treatment For Atrial Fibrillation In Less Developed Countries

Atrial fibrillation (AF) is the most common arrhythmia and is a major cardiovascular challenge due to its close association with increased morbidity and mortality. Although the incidence and prevalence of AF is slightly lower in developing countries than in developed countries, the AF-associated risk of stroke is similar. Treatment of AF is far from satisfactory in developing countries, which may be due to limited health-care resources and social and racial characteristics that differ from Western populations. Chronic rate control is still the main treatment strategy of persistent AF because anti-arrhythmic drugs have only a modest long-term effect on maintenance of sinus rhythm, and no superior impact in terms of cardiovascular outcomes. With the development of ablation techniques and strategies, more AF patients received catheter ablation, although the benefit, complications, and high recurrence rate associated with AF ablation remain under investigation. Improvement in antithrombotic therapy of AF has been observed, although still fewer patients receive oral anticoagulants in developing countries than in Western countries. Novel treatment for the prevention of thromboembolism, such as new oral anticoagulants with different mechanisms of action or the percutaneous transcatheter closure of the left atrial appendage, has recently been introduced in developing countries as an alternative option for the prevention of AF-associated strokes. More data are needed regarding upstream therapy.

Rationale and design of VENTURE-AF: a randomized, open-label, active-controlled multicenter study to evaluate the safety of rivaroxaban and vitamin K antagonists in subjects undergoing catheter ablation for atrial fibrillation

PURPOSE

To evaluate the safety of uninterrupted rivaroxaban, a novel oral anticoagulant that directly inhibits factor Xa, and a vitamin K antagonist (VKA) in eligible adult patients with nonvalvular AF (NVAF) who are scheduled for a catheter ablation.

METHODS/DESIGN

This is a prospective, randomized, open-label, active-controlled, global multicenter safety study of up to 250 randomized patients. Eligible patients with paroxysmal or persistent NVAF, a left ventricular ejection fraction >40 %, and a creatinine clearance >50 mL/min will be randomized 1:1 to rivaroxaban 20 mg orally once daily or to dose-adjusted oral VKA (recommended international normalized ratio (INR) 2.0-3.0) and stabilized on anticoagulation therapy for 1-7 days (if no intracardiac thrombus on transesophageal echocardiogram (TEE) immediately prerandomization/post-randomization or if 3 weeks of sufficient anticoagulation is documented) or for 4-5 weeks (if no TEE, no documented 3 weeks of sufficient anticoagulation, or by patient choice). During catheter ablation, heparin will be administered (ACT-targeted range = 300-400 s) after catheter ablation, and VKA will be managed per usual care. The next dose of rivaroxaban will be provided at least 6 h after establishment of hemostasis. The primary endpoint will be the incidence of post-procedure major bleeding events observed during the first 30 ± 5 days post-ablation. Secondary endpoints will include post-procedure thromboembolic events, additional bleeding, time-to-event, and medication adherence.

RELEVANCE

This study is intended to provide information about the safety characteristics of rivaroxaban in patients with NVAF undergoing catheter ablation.

Potential use of NOACs in developing countries: pros and cons

PURPOSE

Although vitamin K antagonists (VKAs) are effective for long-term thromboprophylaxis in atrial fibrillation (AF), their limitations have led to widespread underutilisation, especially in the developing world. Novel oral anticoagulants (NOACs) have emerged as promising alternatives to VKAs, although there are some particular considerations and challenges to their introduction in developing countries. This review summarises the current state of antithrombotic management of AF in the developing world, explores the early evidence for the NOACs and describes some of the special considerations that must be taken into account when considering the role of the NOACs within developing countries' health care systems.

METHODS

A literature search was conducted via PubMed and Google Scholar to find articles published in English between the years 2000 to 2014. Search terms used were "atrial fibrillation", "oral anticoagulants", "warfarin", "NOACs", "dabigatran", "rivaroxaban", "apixaban", "edoxaban", "time in therapeutic range", "International Normalized Ratio" "cost-effectiveness", "stroke", "adverse-drug reactions" and "drug-drug interactions", together with the individual names of developing countries as listed by the World Bank. We reviewed the results of randomized clinical trials, relevant retrospective and prospective studies, case-studies and review articles.

RESULTS

Many developing countries lack or have sporadic data on the quality of AF management, making it difficult to anticipate the potential impact of NOACs in these settings. The utilisation of anticoagulants for AF appears highly variable in developing countries. Given the issues associated with VKA therapy in many developing countries, NOACs offer some potential advantages; however, there is insufficient evidence to advocate the widespread replacement of warfarin at present. VKAs may continue to have a role in selected patients or countries, especially if alternative monitoring strategies can be utilised.

CONCLUSION

The evaluation of the introduction of NOACs should consider safety, budget concerns and the quality of oral anticoagulation care achieved by each country. Prospective registries will be important in developing countries to better elucidate the comparative safety, efficacy and cost-effectiveness of NOACs and VKAs as NOACs are introduced into practice.

Atrial natriuretic peptide as a predictor of atrial fibrillation in a male population study. The Study of Men Born in 1913 and 1923

BACKGROUND

Atrial fibrillation is one of the most common arrhythmias in clinical practice and it is often diagnosed after a complication occurs. The study aimed to evaluate the predictive value of atrial natriuretic peptide (ANP) for atrial fibrillation in a male population-based study.

METHODS AND RESULTS

This study is a part of the "Study of Men Born in 1913 and 1923", a longitudinal prospective cohort study of men, living in the city of Gothenburg in Sweden. A population-based sample of 528 men was investigated in 1988 when they were aged 65 years (n=134) and 75 years (n=394), and they were followed up for 16 years. Blood samples were collected from all 528 men at baseline and plasma ANP levels were analyzed by radioimmunoassay. Hazard ratios were estimated by competing-risk regression analysis. One hundred five participants were excluded because of a prior diagnosis of atrial fibrillation, congestive heart failure, severe hypertension, or severe chronic renal insufficiency. Of the remaining 423 participants, 90 men were diagnosed with atrial fibrillation over the 16-year follow-up. In multivariable analysis, men in the two highest quartiles of ANP levels had a significantly higher risk for atrial fibrillation compared with men in the lowest ANP quartile. The adjusted ratio was 3.14 (95% CI 1.59-6.20) for the third ANP quartile and 3.36 (95% CI 1.72-6.54) for the highest quartile of ANP level.

CONCLUSIONS

In this population-based longitudinal study, we found that elevated ANP levels at baseline predicted atrial fibrillation during a follow-up time of 16 years.