Prevalence of atrial fibrillation in elderly subjects (the Cardiovascular Health Study)

Saudi Atrial Fibrillation Survey

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. The Saudi Atrial Fibrillation Survey registry was designed to provide epidemiological and clinical data on patients with AF. The registry included 400 consecutive patients who met the eligibility criteria. Control of AF at the time of the initial visit was achieved by 211 (52.75%) patients. Cardiovascular risk profile of the patients with AF was smoking 92 (23.5%), hypertension 253 (63.25%), diabetes 192 (48%), and dyslipidemia 173 (44%). Rate control was the most frequent management strategy (in 265 patients, 66.2%) whereas rhythm control was chosen in 48 (12%) patients. Both strategies were attempted in 5 (1.2%) patients. This is the first nationwide registry of patients with AF in Saudi Arabia. Compared to developed countries, our patients with AF are relatively young and have higher rates of diabetes and rheumatic heart disease. Rate control is the main strategy currently used for managing AF.

Stroke Risk Factors, Course and Long-Term Functional Outcome of First-Ever Stroke in Women

BACKGROUND: Recently, many studies regarding stroke in men and women showing differences in its incidence and course have been conducted, but the cause of sex differences remains unclear.AIM: The objective of study was to assess the incidence of selected stroke risk factors, the course and long-term consequences of first-ever stroke in women.MATERIAL AND METHODS: 304 women and 207 men with first-ever stroke were studied. We assessed: age at which stroke occurred; presence of hypertension, lipid disorders, coronary disease, atrial fibrillation, diabetes, carotid/cerebral artery stenoses; stroke aetiology, state on days 1 (NIHSS) and 90 (Rankin).RESULTS: The age at which first-ever stroke occurred was higher in women (p = 0.030). Atrial fibrillation occurred more frequently in them (p = 0.0007). Hypertension and coronary disease occurred less commonly in women under 55 (p = 0.038 and 0.035 respectively). In women < 55, lipid disorders (p = 0.004) and diabetes (p = 0.018) were observed more rarely, they were more common in > 55 group (p = 0.042 and 0.023). In women, carotid artery stenoses were less common (p = 0.07), cardiogenic stroke more common (p = 0.001). They were in worse neurological state both on day 1 (p = 0.001) and 90 (p = 0.033) of disease.CONCLUSIONS: Cardiogenic stroke is significantly more common in women. Women exhibit more severe post-stroke disability, resulting in more frequent use of institutional care.

Number of P-wave fragmentations on P-SAECG correlates with infiltrated atrial fat

BACKGROUND

Although atrial fibrillation (AF) triggers are known, the underlying AF substrate is less well understood. The goal of our study was to explore correlations between electrophysiological and structural characteristics of atria in patients with paroxysmal AF and individuals at AF risk.

METHODS

Patients in sinus rhythm (N = 90; age 57 ± 10 year; 55 men [63.2%]) with structural heart disease and paroxysmal AF (n = 12 [13%]), or with AF risk factors and LVEF > 35% (n = 78), underwent SAECG and cardiac magnetic resonance study. Interatrial and epicardial fat was analyzed with a Dark-blood DIR-prepared Fat-Water-separated sequence in the horizontal longitudinal axis. All local P-wave extrema were identified on SAECG leads during sinus rhythm. A P-wave fragmentation (Pf) was defined as an absolute difference between adjacent extrema which was above three standard deviations of noise, and was normalized by the duration of the P wave in the corresponding lead.

RESULTS

The Pf was greater on the filtered than on the unfiltered P-SAECG signal (13.1 ± 3.8 vs. 3.4 ± 1.2; P < 0.0001). Pf was the greatest on the Y lead (13.0 ± 3.5 on Y lead vs. 12.1 ± 3.4 on Z lead; P = 0.003. Pf on Z lead correlated with interatrial fat index (r = 0.544; P = 0.001). Epicardial fat significantly correlated with body mass index (BMI; r = 0.302; P = 0.015). After adjustment for BMI, left atrium (LA) size, epicardial fat, and interatrial septum width, interatrial fat independently associated with the Pf on Z lead (β-coefficient 0.009 [95%CI 0.0003-0.019]; P = 0.043).

CONCLUSIONS

Infiltrated atrial fat correlates with discontinuous conduction on posterior LA wall and represents AF early substrate.

Detection of paroxysmal atrial fibrillation or flutter in patients with acute ischemic stroke or transient ischemic attack by Holter monitoring

BACKGROUND AND PURPOSE

Paroxysmal atrial fibrillation and flutter are strong risk factors for stroke. Due to high recurrence rate of ischemic events and given the benefit of oral anticoagulation over antiplatelet drugs, it is important to identify this arrhythmia. Unfortunately, paroxysmal AF or flutter is asymptomatic in majority and therefore, difficult to detect.

METHODS

Consecutive patients presenting with symptoms of acute ischemic stroke or transient ischemic attack were included. All patients free of AF or flutter on presentation underwent 24 h Holter monitoring within 7 days of admission.

RESULTS

Overall, fifty two (52) patients (mean age 59.51 ± 13.45 years) with acute stroke (80.8%) and TIA (19.8%) underwent 24 h Holter monitoring. Paroxysmal AF was detected in 3 cases (5.8%), all 3 patients had acute stroke and were older than age 60 years. Type of stroke was the only factor which was associated with greater risk of having paroxysmal AF or flutter, AF accounted for 50% cases (2 out of 4) of clinically suspected cardio embolic stroke.

CONCLUSION

Screening consecutive patients with ischemic stroke with routine Holter monitoring will identify new atrial fibrillation/flutter in approximately one in 17 patients. Older age and type of stroke are strongly associated with increased risk. By carefully selecting the patients, the detection rates could be further increased.

Sex differences in cardiovascular outcomes, pharmacological treatments and indicators of care in patients with newly diagnosed diabetes: Analyses on administrative database

BACKGROUND

The impact of diabetes on cardiovascular disease in both sexes is known, but the specifics have not been fully clarified. We investigated whether sex-related differences exist in terms of management and hospitalization in patients with newly diagnosed diabetes.

METHODS

We examined the rates of hospitalization for cardiovascular causes, mortality, treatments and management of patients with diabetes compared to subjects without, from administrative database. Interaction between sex and diabetes on clinical outcomes were calculated using a Cox regression model. Pharmacological treatments and recommended examinations by sex were calculated using logistic regression.

RESULTS

From 2002 to 2006, 158,426 patients with diabetes and 314,115 subjects without were identified and followed up for a mean of 33 months (± 17.5). Diabetes confers a higher risk for all clinical outcomes. Females with diabetes have a risk profile for hospitalization for coronary heart disease comparable to males without (4.6% and 5.3%). Interaction between sex and diabetes shows that females with diabetes had an added 19% higher risk of total death (95% CI 1.13-1.24). No differences were observed in hospitalizations, although females with diabetes were less likely to undergo revascularization after myocardial infarction. Females received cardiovascular prevention drugs less frequently than males and had a slight tendency to get fewer examinations.

CONCLUSION

Diabetes is linked to a higher increase of mortality in females relative to males. This might reflect sex differences in the use of revascularization procedures or therapeutic regimens. Closer attention and implementation of standard care for females are necessary from the onset of diabetes.

Stent implantation into intracranial part of internal carotid artery in a patient with recurrent stroke, atrial fibrillation and iatrogenic bleeding during anticoagulant therapy

Cardiovascular diseases are the leading cause of stroke. We present a 45-year-old woman with left hemisphere stroke, in which two sources of cerebral embolism were detected: atrial fibrillation and stenosis of intracranial part of left internal carotid artery. Oral anticoagulant therapy was used. The patient was qualified for intracranial revascularization. During anticoagulant therapy iatrogenic bleeding and then left hemisphere stroke occurred. Ultimately, the stent was implanted into the intracranial part of the internal carotid artery. Due to atrial fibrillation the patient is qualified for percutaneous closure of the left atrial appendage.

The impact of age on the epidemiology of atrial fibrillation hospitalizations

BACKGROUND

Given that 4 million individuals in the United States have atrial fibrillation, understanding the epidemiology of this disease is crucial. We sought to identify and characterize the impact of age on national atrial fibrillation hospitalization patterns.

METHODS

The study sample was drawn from the 2009-2010 Nationwide Inpatient Sample. Patients hospitalized with a principal International Classification of Diseases, 9th Revision discharge diagnosis of atrial fibrillation were included. Patients were categorized as "older" (≥65 years) or "younger" (<65 years) for the purposes of analysis. The outcomes measured included hospitalization rate, length of stay, in-hospital mortality, and discharge status.

RESULTS

We identified 192,846 atrial fibrillation hospitalizations. There was significant geographic variation in hospitalizations for both younger and older age groups. States with high hospitalizations differed from those states known to have high stroke mortality. Younger patients (33% of the sample) were more likely to be obese (21% vs 8%, P < .001) and to use alcohol (8% vs 2%, P < .001). Older patients were more likely to have kidney disease (14% vs 7%, P < .001). Both age groups had high rates of hypertension and diabetes. Older patients had higher in-hospital mortality and were more likely to be discharged to a nursing or intermediate care facility.

CONCLUSIONS

Younger patients account for a substantial minority of atrial fibrillation hospitalizations in contemporary practice. Younger patients are healthier, with a different distribution of risk factors, than older patients who have higher associated morbidity and mortality.

Quality of life in patients with atrial fibrillation: how to assess it and how to improve it

Atrial fibrillation (AF) is the most frequent cardiac rhythm disorder and presents a considerable public health burden that is likely to increase in the next decades due to the ageing population. Current management strategies focus on the heart rate and rhythm control, thromboembolism prevention, and treatment of underlying diseases. The concept of quality of life (QoL) has gained significant importance in recent years as an outcome measure in AF studies evaluating therapeutic interventions and as a relevant component of a comprehensive treatment plan. Quality of life is impaired in the majority of patients with AF, and both rate and rhythm control strategies show significant improvement in QoL measures in highly symptomatic patients. This article reviews generic and specialized instruments for measuring QoL in the context of AF, discusses their applications and limitations to integration in clinical practice, and addresses the potential of early therapy for improving QoL outcomes. The development and validation of new QoL assessment tools will have a central role in the advancement of therapies and treatment guidelines for AF.

Prevalence and management of atrial fibrillation in primary care: a case study

AIM

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a major predisposing risk factor for stroke. Current UK guidelines propose stroke-risk stratification of AF patients. Anticoagulation with warfarin is recommended for high risk patients, whereas treatment with aspirin alone is advised for those at low risk. The aim of this audit was to review practice at our institution and ascertain if guidelines on AF treatment were being followed.

METHODS

A retrospective review of all patients diagnosed with non-valvular AF in June 2010 was undertaken. Patient records were reviewed to collect demographic and co-morbidity data relevant to stroke risk stratification. This was subsequently used to stratify patients according to stroke-risk using the CHADS2 scoring system. The use of anticoagulation and anti-platelet medication as well as any documented reasons for the omission of anticoagulation in high risk patients was noted.

RESULTS

The prevalence of non-valvular AF in our practice population was 1.5% (151/10,155); 70% (105/151) of AF patients were found to be at high risk of stroke; 36% (38/105) of high risk patients were not on anticoagulation and the majority (58%) of these patients had no clear reason documented for the omission of warfarin. Of the 15 patients at low risk of stroke, 12 (80%) were on warfarin. Seven (4.4%) of the 151 AF patients were on both warfarin and aspirin and six (4%) were on neither medication. The commonest documented reasons for omission of warfarin in the high risk group were dementia and a history of gastrointestinal bleeding.

DISCUSSION

The lack of documentation on withholding a proven beneficial treatment in high risk patients could potentially leave physicians open to medico-legal scrutiny. Maintaining low risk patients on anticoagulation may expose them to unnecessary risk. We recommend the use of automated audit tools designed to improve compliance with national guidelines.

Atrial fibrillation and stroke prevention

There is overwhelming evidence from randomized trials and systematic reviews to indicate the benefit of thromboprophylaxis in patients with atrial fibrillation. In moderate- to high-risk subjects, oral anticoagulation with warfarin reduces stroke by two-thirds, while aspirin reduces stroke by 22%. The latter result is similar to that seen for stroke reduction with antiplatelet therapy in vascular disease. Numerous studies have shown that less than half the patients eligible for warfarin therapy actually receive it and under- or overanticoagulation is common. This leads to many missed opportunities in optimizing stroke prevention in atrial fibrillation. The limitations of existing oral anticoagulants have resulted in the development of many new drugs. The aim of this review is to provide a brief overview of thromboprophylaxis in atrial fibrillation, and the opportunities for improvement in the provision made for thromboprophylaxis.

Curative surgery for atrial fibrillation: current status and minimally invasive approaches

Atrial fibrillation (AF) is the most common disorder of heart rhythm. Affecting 2.2 million Americans and millions more worldwide, AF is a dangerous and costly epidemic. AF is associated with an increased risk of stroke, premature death and billions of dollars in healthcare expenditures. Traditional treatments of AF, which include medications aimed at rate or rhythm control have been disappointing, leaving most patients in AF and failing to eliminate the risk of stroke. In contrast, advances in surgical and catheter-based therapies offer the chance to cure AF. With more than a decade of experience, surgical treatment of AF is the most effective means of curing this arrhythmia. The classic Maze procedure eliminates AF in more than 90% of patients. A complex but safe operation, the Maze procedure is applied by relatively few surgeons. Recently, however, there has been a resurgence of interest in surgical treatment of AF. Advances in the understanding of the pathogenesis of AF and development of new ablation technologies enable surgeons to perform pulmonary vein ablation and create linear left atrial lesions rapidly and safely. Such procedures, which are generally applied to patients with AF and valvular heart disease, add 15 minutes to operative time and cure AF in approximately 80% of patients. New ablation technologies have been adapted to enable thoracoscopic and minimally invasive surgical AF ablation in patients with isolated AF, extending the possibility of cure to large numbers of patients.

Atrial fibrillation: a review of recent studies with a focus on those from the duke clinical research institute

Atrial fibrillation is the most common arrhythmia and accounts for one-third of hospitalizations for rhythm disorders in the United States. The prevalence of atrial fibrillation averages 1% and increases with age. With the aging of the population, the number of patients with atrial fibrillation is expected to increase 150% by 2050, with more than 50% of atrial fibrillation patients being over the age of 80. This increasing burden of atrial fibrillation will lead to a higher incidence of stroke, as patients with atrial fibrillation have a five- to sevenfold greater risk of stroke than the general population. Strokes secondary to atrial fibrillation have a worse prognosis than in patients without atrial fibrillation. Vitamin K antagonists (e.g., warfarin), direct thrombin inhibitors (dabigatran), and factor Xa inhibitors (rivaroxaban and apixaban) are all oral anticoagulants that have been FDA approved for the prevention of stroke in atrial fibrillation. This review will summarize the experience of anticoagulants in patients with atrial fibrillation with a focus on the experience at the Duke Clinic Research Institute.

Efficacy of Combination Therapy of Statin and Vitamin C in Comparison with Statin in the Prevention of Post-CABG Atrial Fibrillation

PURPOSE

Atrial fibrillation (AF) is the most frequent arrhythmia that follows coronary artery bypass graft (CABG). Patients developing postoperative AF (POAF) have significantly higher mortality rates. The consistent prophylactic effectiveness of statins and vitamin C are well-accepted; however, no evaluation on combined therapy has been performed. We aimed at assessing the efficacy of combination therapy with statin and vitamin C in comparison with statin alone in the prevention of post CABG-AF.

METHODS

In a randomized double blind clinical trial, 120 candidates of CABG were recruited in Tabriz Madani Educational Center in a 15-month period of time. Patients were randomized into two groups of 60 receiving oral atorvastatin (40mg) plus oral vitamin C (2g/d operation day and 1g/d for five consequent days) for intervention group and oral atorvastatin (40mg) for control group. Occurrence of post CABG AF was compared between the two groups.

RESULTS

There were 60 patients, 43 males and 17 females with a mean age of 61.0±11.5 (29-78) years, in the intervention group and sixty patients, 39 males and 21 females with a mean age of 60.5±11.3 (39-81) years, in the control group. The post CABG AF occurred in 6 cases (10%) in the interventional group and 15 patients (25%) in the controls (P=0.03, odds ratio=0.33, 95% confidence interval 0.12-0.93).

CONCLUSION

Based on our findings, combination prophylaxis against post CABG AF with oral atorvastatin plus vitamin C is significantly more effective than single oral atorvastatin.

Worldwide epidemiology of atrial fibrillation: a Global Burden of Disease 2010 Study

BACKGROUND

The global burden of atrial fibrillation (AF) is unknown.

METHODS AND RESULTS

We systematically reviewed population-based studies of AF published from 1980 to 2010 from the 21 Global Burden of Disease regions to estimate global/regional prevalence, incidence, and morbidity and mortality related to AF (DisModMR software). Of 377 potential studies identified, 184 met prespecified eligibility criteria. The estimated number of individuals with AF globally in 2010 was 33.5 million (20.9 million men [95% uncertainty interval (UI), 19.5-22.2 million] and 12.6 million women [95% UI, 12.0-13.7 million]). Burden associated with AF, measured as disability-adjusted life-years, increased by 18.8% (95% UI, 15.8-19.3) in men and 18.9% (95% UI, 15.8-23.5) in women from 1990 to 2010. In 1990, the estimated age-adjusted prevalence rates of AF (per 100 000 population) were 569.5 in men (95% UI, 532.8-612.7) and 359.9 in women (95% UI, 334.7-392.6); the estimated age-adjusted incidence rates were 60.7 per 100 000 person-years in men (95% UI, 49.2-78.5) and 43.8 in women (95% UI, 35.9-55.0). In 2010, the prevalence rates increased to 596.2 (95% UI, 558.4-636.7) in men and 373.1 (95% UI, 347.9-402.2) in women; the incidence rates increased to 77.5 (95% UI, 65.2-95.4) in men and 59.5 (95% UI, 49.9-74.9) in women. Mortality associated with AF was higher in women and increased by 2-fold (95% UI, 2.0-2.2) and 1.9-fold (95% UI, 1.8-2.0) in men and women, respectively, from 1990 to 2010. There was evidence of significant regional heterogeneity in AF estimations and availability of population-based data.

CONCLUSIONS

These findings provide evidence of progressive increases in overall burden, incidence, prevalence, and AF-associated mortality between 1990 and 2010, with significant public health implications. Systematic, regional surveillance of AF is required to better direct prevention and treatment strategies.

Estimating the prevalence of atrial fibrillation in a general population using validated electronic health data

Background

The purpose of this study was to determine the prevalence of atrial fibrillation (AF) in the general population and to validate an administrative diagnosis register, ie, the National Patient Register (NPR), and an electrocardiography (ECG) database in estimating disease prevalence.

Methods

The study was conducted in a well defined region in northern Sweden (population n=75,945) which consists of one hospital and eleven primary health care centers. Subjects with AF were identified by searching the combined inpatient and outpatient International Classification of Diseases (ICD)-based NPR (ICD-10 code I48) and an ECG database with computer-interpreted AF from January 1, 2004 to December 31, 2010. All identified cases with AF were validated.

Results

AF was confirmed in 2,274 patients. The overall prevalence was 3.0% (3.4% in men and 2.6% in women). AF prevalence rose steadily with age, and was 16.8% in patients aged 75 years and older and 21.9% in patients 85 years and older. Of all patients with validated AF, the NPR identified 93.2%. The ECG database identified an additional 6.8%, of which 81% were over 70 years of age. According to the NPR, the proportion of false positives and false negatives was 3.5% and 6.8%, respectively. The corresponding figure for the ECG database was 11.3% and 9.2%, respectively.

Conclusion

Our study shows a high prevalence of AF, especially among the elderly. Searching the ECG database enhanced the detection of AF. The reliability of the NPR was high, with a relatively low proportion of false positives and negatives.

Carotid Atherosclerosis and Incident Atrial Fibrillation

Objective—

Atrial fibrillation (AF) and atherosclerotic vascular disease are closely entangled disorders and often coexist. Whether atherosclerosis predisposes to the development of AF has not been fully elucidated.

Approach and Results—

This study was performed within the framework of the Bruneck Study, a population-based survey with near-complete participation (932 of 1000), long-term follow-up (1990–2010), and thorough assessment of AF. The carotid arteries served as a window to systemic atherosclerosis and were scanned every 5 years. Pooled logistic regression and multistate proportional hazards models were used to identify risk predictors of incident AF and effects of AF on mortality. During follow-up, 118 new cases of AF were detected (incidence per 1000 person-years of 8.1; 95% confidence interval, 6.8–9.6). Individuals with atherosclerosis were more likely to develop AF than individuals without (odds ratio, 1.8; 95% confidence interval, 1.1–3.1; P =0.021). This finding applied to women and men and to both baseline and incident atherosclerosis during follow-up. Subjects with atherosclerosis and AF were significantly more likely to die than those with either condition alone ( P =0.0034), and mortality in this group was ≈4-fold compared with individuals free of atherosclerosis and AF (hazard ratio, 4.2; 95% confidence interval, 2.6–6.8; P <0.0001).

Conclusions—

We found that subjects with carotid atherosclerosis are at high risk of developing AF.

N-terminal pro-B-type natriuretic peptide as a predictor of incident atrial fibrillation in the Multi-Ethnic Study of Atherosclerosis: the effects of age, sex and ethnicity

OBJECTIVE

Atrial fibrillation (AF) is a common source of medical costs, morbidity and mortality. NT pro-brain natriuretic peptide (BNP) is a remarkably strong predictor of AF in older whites; we aimed to assess if this biomarker was as predictive in other racial groups.

DESIGN

We used covariate-adjusted Cox model regressions to estimate the HRs of developing AF as a function of NT proBNP, and tested for interactions of NT proBNP with age, gender and race/ethnicity.

SETTING

The Multi-Ethnic Study of Atherosclerosis (MESA).

PATIENTS

5518 subjects were followed over a median of 7.6 years. During this time, 267 developed AF.

RESULTS

NT proBNP was statistically significantly associated with incident AF; for ln NT proBNP, the adjusted HR was 2.2 (95% CI 1.9 to 2.5). Assessed by quintiles, the relationship between NT proBNP was strong and graded; the unadjusted HR for the highest quintile of NT proBNP was 23.7 (95% CI 11.1 to 50.6) and adjusted was 11.4 (95% CI 5.1 to 25.3). NT proBNP was an excellent predictor of incident AF in the younger and older age groups, in men and women and in the different race/ethnicity groups: the HR for ln NT proBNP as a predictor of incident AF ranged from 2.0 to 3.9 in each subgroup.

CONCLUSIONS

NT proBNP is a robust predictor of incident AF; its prognostic value is more significant in younger patients and women compared with older patients and men. NT proBNP was also as strongly predictive in black patients, Hispanics and Asian/Chinese as in white patients despite a lower incidence of arrhythmia.

The QT interval and risk of incident atrial fibrillation

BACKGROUND

Abnormal atrial repolarization is important in the development of atrial fibrillation (AF), but no direct measurement is available in clinical medicine.

OBJECTIVE

To determine whether the QT interval, a marker of ventricular repolarization, could be used to predict incident AF.

METHODS

We examined a prolonged QT interval corrected by using the Framingham formula (QT(Fram)) as a predictor of incident AF in the Atherosclerosis Risk in Communities (ARIC) study. The Cardiovascular Health Study (CHS) and Health, Aging, and Body Composition (ABC) study were used for validation. Secondary predictors included QT duration as a continuous variable, a short QT interval, and QT intervals corrected by using other formulas.

RESULTS

Among 14,538 ARIC study participants, a prolonged QT(Fram) predicted a roughly 2-fold increased risk of AF (hazard ratio [HR] 2.05; 95% confidence interval [CI] 1.42-2.96; P < .001). No substantive attenuation was observed after adjustment for age, race, sex, study center, body mass index, hypertension, diabetes, coronary disease, and heart failure. The findings were validated in Cardiovascular Health Study and Health, Aging, and Body Composition study and were similar across various QT correction methods. Also in the ARIC study, each 10-ms increase in QT(Fram) was associated with an increased unadjusted (HR 1.14; 95% CI 1.10-1.17; P < .001) and adjusted (HR 1.11; 95% CI 1.07-1.14; P < .001) risk of AF. Findings regarding a short QT interval were inconsistent across cohorts.

CONCLUSIONS

A prolonged QT interval is associated with an increased risk of incident AF.

Atrial Fibrillation - A Common Ground for Neurology and Cardiology

Atrial fibrillation (AF) has a huge impact on clinical stroke because it is the primary cause of cardio-embolism, which constitutes ~20% of all strokes. As a result, there is a great need to explore safer and more effective primary and secondary prophylactic agents. In this article, we discuss the overlapping issues pertaining to AF from both a neurology and cardiology standpoint. We focus on the dynamic interplay of neurovascular and cardiovascular diseases in relation to AF, traditional and novel risk factors for AF leading to stroke, impact of AF on cognitive decline, and current upstream medical and surgical options for embolism prophylaxis.

Recent developments in understanding epidemiology and risk determinants of atrial fibrillation as a cause of stroke

The prevalence of atrial fibrillation (AF) is increasing because of the aging population and advances in the treatment of acute cardiac conditions. It is now approaching epidemic proportions and is associated with significant clinical and public health consequences. Risk factors for the development of AF are numerous and varied and highlight potential treatment measures that could help prevent the occurrence of AF. The emergence of novel risk factors might allow us to increase our understanding of the pathophysiology of the condition and develop novel therapeutic targets. Stroke is the most devastating consequence of AF, and can be prevented with effective oral anticoagulation in patients at increased stroke risk. Our understanding of stroke risk has advanced; we know that the risk is not homogenous and also that only the very lowest risk patients do not benefit from anticoagulation. Clinicians should target their efforts on identifying this "truly low-risk" patient cohort and consider offering formal anticoagulation to all other AF patients. The purpose of this review is to consider the traditional and emerging risk factors for the development of AF itself, and the risk factors for stroke in AF patients and how knowledge of these risk factors can affect clinical practice.

Reduced forced expiratory volume is associated with increased incidence of atrial fibrillation: the Malmo Preventive Project

AIMS

Reduced forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) have been associated with increased incidence of cardiovascular diseases. However, whether reduced lung function is also a risk factor for incidence of atrial fibrillation (AF) is still unclear. We aimed to determine whether lung function predicted AF in the Malmö Preventive Project, a large population-based cohort with a long follow-up.

METHODS AND RESULTS

The study population consisted of 7674 women and 21 070 men, mean age 44.6 years. The cohort was followed on average for 24.8 years, during which time 2669 patients were hospitalized due to AF. The incidence of AF in relationship to quartiles of FEV1 and FVC and per litre decrease at baseline was determined using a Cox proportional hazards model adjusted for age, height, weight, current smoking status, systolic blood pressure, erythrocyte sedimentation rate, and fasting blood glucose. Forced expiratory volume in one second was inversely related to incidence of AF (per litre reduction in FEV1) hazard ratio (HR): 1.39 [95% confidence interval (CI): 1.16-1.68; P = 0.001] for women, and HR: 1.20 (95% CI: 1.13-1.29; P < 0.0001) for men. Forced vital capacity was also inversely related to incidence of AF (per litre reduction in FVC) HR: 1.20 (95% CI: 1.03-1.41; P = 0.020) for women, and HR: 1.08 (95% CI: 1.02-1.14; P = 0.01) for men. This relationship was consistent in non-smokers as well as smokers, and among individuals younger than the median age of 45.8 years or normotensive subjects.

CONCLUSION

Impaired lung function is an independent predictor of AF. This may explain some risk of AF that is currently unaccounted for.

Clinical strategies for selecting oral anticoagulants in patients with atrial fibrillation

Atrial fibrillation is a common arrhythmia. One of the important aspects of the management of atrial fibrillation is stroke prevention. Warfarin has been the longstanding anticoagulant used for stroke prevention in patients with atrial fibrillation. There are now three novel oral anticoagulants, which have been studied in randomized controlled trials and subsequently approved by the Federal Drug Administration for stroke prevention in patients with atrial fibrillation. Special patient populations, including renal insufficiency, elderly, prior stroke, and extreme body weights, were represented to varying degrees in the clinical trials of the novel oral anticoagulants. Furthermore, there is variation in the pharmacokinetics and pharmacodynamics of each anticoagulant, which affect the patient populations differently. Patients and clinicians are faced with the task of selecting among the available anticoagulants, and this review is designed to be a tool for clinical decision-making.

A comparison of clinical characteristics and long-term prognosis in asymptomatic and symptomatic patients with first-diagnosed atrial fibrillation: the Belgrade Atrial Fibrillation Study

BACKGROUND

To investigate baseline characteristics and long-term prognosis of carefully characterized asymptomatic and symptomatic patients with atrial fibrillation (AF) in a 'real-world' cohort of first-diagnosed non-valvular AF over a 10-year follow-up period.

METHODS AND RESULTS

We conducted an observational, non-interventional, and single-centre registry-based study of consecutive first-diagnosed AF patients. Of 1100 patients (mean age 52.7±12.2 years and mean follow-up 9.9±6.1 years), 146 (13.3%) had asymptomatic AF. Persistent or permanent AF, slower ventricular rate during AF (<100/min), CHA2DS2-VASc score of 0, history of diabetes mellitus and male gender were independent baseline risk factors for asymptomatic AF presentation (all p<0.01) with a good predictive ability of the multivariable model (c-statistic 0.86, p<0.001). Kaplan-Meier 10-year estimates of survival free of progression of AF (log-rank test=33.4, p<0.001) and ischemic stroke (log-rank test=6.2, p=0.013) were significantly worse for patients with asymptomatic AF compared to those with symptomatic arrhythmia. In the multivariable Cox regression analysis, intermittent asymptomatic AF was significantly associated with progression to permanent AF (Hazard Ratio 1.6; 95% CI, 1.1-2.2; p=0.009).

CONCLUSIONS

In a 'real-world' setting, patients with asymptomatic presentation of their first-diagnosed AF could have different risk profile and long-term outcomes compared to those with symptomatic AF. Whether more intensive monitoring and comprehensive AF management including AF ablation at early stage following the incident episode of AF and increased quality of oral anticoagulation could alter the long-term prognosis of these patients requires further investigation.

The burden of atrial fibrillation in the Netherlands

BACKGROUND

Atrial fibrillation (AF) is the most common sustained atrial arrhythmia and it is independently associated with an increased morbidity and mortality. As a result of the high prevalence of AF, the economic and clinical impact of the disease is substantial. This study describes the economic and clinical impact of AF in the Netherlands.

METHODS

Epidemiological data on AF in the Netherlands were projected on population estimates of the Netherlands in 2009 and combined with data on the cost of AF and its interventions.

RESULTS

Overall prevalence of AF in the Netherlands is 5.5% in the population over 55 years, corresponding to about 250,000 AF patients. The prevalence increases with age, and the mean age of AF patients is 69.3 years. Incidence of AF in the Netherlands varies with age, from 1188 new cases in the age group of 55 to 59 up to 7074 new cases in the age group 75 to 79. Total new cases amounts to 45,085 patients per year in the Netherlands. Total costs of AF in the Netherlands are <euro> 583 million, of which the majority (70%) were accounted for by hospitalisations and in-hospital procedures. Pharmacotherapeutic management of AF totalled <euro> 17 million in the Netherlands in 2009.

DISCUSSION

AF is a serious disease with a high clinical and economic burden, especially due to hospitalisations as a result of cardiovascular events. The number of patients with AF in the Netherlands is considerable and will increase with the ageing population in the future.

Meta-analysis of the therapeutic effects of various methods for the treatment of chronic atrial fibrillation

The aim of this study was to analyze the therapeutic effects of various methods for the treatment of chronic atrial fibrillation (AF). Randomized controlled trials (RCT) concerning drug therapy and catheter ablation for the treatment of chronic AF were retrieved. The RevMan 5.1 software package was used for the meta-analysis. A total of 20 papers were assessed in this study. The results of the analysis indicated that the success rate was lower [odds ratio (OR), 8.94; 95% confidence interval (CI), 4.70-17.02; P<0.0001] and the relapse rate was higher (OR, 0.07, 95% CI, 0.05-0.10; P<0.0001) for drug therapy compared with that for catheter ablation. With regard to different catheter ablation procedures, the success rate for pulmonary vein antrum isolation (PVAI) was lower compared with that for PVAI plus complex fractionated atrial electrogram (CFAE; OR, 0.53; 95% CI, 0.37-0.78; P=0.0001). Pulmonary vein isolation (PVI) plus left atrial ablation (LAA) had a higher success rate compared with PVI alone (OR, 2.79; 95% CI, 1.59-4.88, P=0.0003). There was not identified to be a significant difference in the success rates between PVAI and CFAE (OR, 2.05; 95% CI, 0.06-205.74; P=0.76) or between PVI and circumferential pulmonary vein isolation (CPVI; OR, 0.94; 95% CI, 0.29-3.00; P=0.91). All the funnel plots of publication bias were essentially symmetrical. In conclusion, the success rate was higher and the relapse rate was lower for catheter ablation compared with drug therapy. Among the different procedures of catheter ablation, there were no significant differences in success rate between two single procedures; however, the success rates were higher for the combined methods compared with those for the single methods.

Screening for atrial fibrillation with baseline and intermittent ECG recording in an out-of-hospital population

BACKGROUND

the objective of this study is to investigate the detection rate of undiagnosed atrial fibrillation (AF) with short intermittent ECG recordings during four weeks among out-of-hospital patients, having at least one additional risk factor (CHADS2) for stroke.

METHOD

DESIGN

Cross-sectional study.

SETTING

Eight family practice centres and two hospital-based out-patient clinics in Sweden.

SUBJECTS

989 out-of-hospital patients, without known AF, having one or more risk factors associated with stroke (CHADS2).

INTERVENTIONS

All individuals were asked to perform 10-second handheld ECG recordings during 28 days, twice daily and when having palpitations.

MAIN OUTCOME MEASURES

Episodes of AF on handheld ECG recordings were defined as irregular supraventricular extrasystoles in series with a duration of 10 seconds.

RESULTS

928 patients completed registration. AF was found in 35 of 928 patients; 3.8% (95% confidence interval [CI] 2.7-5.2). These 35 patients had a mean age of 70.7 years (SD ± 7.7; range 53-85) and a median CHADS2 of 2 (range 1-4).

CONCLUSIONS

Intermittent handheld ECG recording over a four week period had a detection rate of 3.8% newly diagnosed AF, in a population of 928 out-of-hospital patients having at least one additional risk factor for stroke. Intermittent handheld ECG registration is a feasible method to detect AF in patients with an increased risk of stroke in whom oral anticoagulation (OAC) treatment is indicated.

Role of cardiac computed tomography and cardiovascular magnetic resonance imaging in guiding management and treatment of patients with atrial fibrillation: state of the art review

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is associated with high morbidity and mortality. In view of an aging population, the prevalence and incidence of AF are on the rise and are expected to double in the coming decades, posing a huge economic burden on already strained resources. New innovative therapies such as pulmonary vein isolation and percutaneous closure of the left atrial appendage have emerged. The current applications of such therapies would not have been possible without the pivotal role of multimodality cardiovascular imaging. The role of echocardiography in guiding therapy has been extensively reviewed. However, there are new data in support of other complementary imaging modalities, mainly cardiac computed tomography and cardiovascular magnetic resonance imaging, which will be the focus of this review.

Long-term success and follow-up after atrial fibrillation ablation

Atrial fibrillation (AF) is the most prevalent sustained arrhythmia in clinical practice. It is associated with significant morbidity and mortality and has been identified as an independent risk factor for ischemic stroke and thromboembolic events. Catheter ablation has become an established rhythm control therapy in patients with highly symptomatic drug-refractory AF. The definition of ablation success remains controversial since current symptom-based or intermittent electrocardiogram monitoring strategies fail to sufficiently disclose rhythm outcome. This failure is mainly related to the high incidence of asymptomatic AF recurrences, the unpredictable nature of arrhythmia relapses, and the poor correlation of symptoms and AF episodes. There is a clear correlation between the intensity of the monitoring strategy and the sensitivity for it to detect arrhythmia recurrences. Furthermore, several clinical studies assessing the long-term efficacy of catheter ablation procedures have reported late AF recurrences in patients who were initially considered responders to catheter ablation. In certain subsets of patients, precise long-term monitoring may help to guide therapy, e.g. patients in whom withdrawal of antithrombotic therapy may be considered if they are free of arrhythmia recurrences. Recently, sub-cutaneous implantable cardiac monitors (ICM) have been introduced for prolonged and continuous rhythm monitoring. The performance of a leadless ICM equipped with a dedicated AF detection algorithm has recently been assessed in a clinical trial demonstrating a high sensitivity and overall accuracy for identifying patients with AF. The clinical impact of ICM-based follow-up strategies, however, has to be evaluated in prospective clinical trials.

Warfarin slows deterioration of renal function in elderly patients with chronic kidney disease and atrial fibrillation

Background

The purpose of this study was to examine whether long-term use of anticoagulants in elderly patients with atrial fibrillation (AF) and chronic kidney disease (CKD) influences renal function.

Methods

In this retrospective observational study, we reviewed the records of 2023 patients who attended our institution for treatment of CKD between January 2001 and September 2012. Inclusion criteria were having been under review for three months or more, age older than 60 years, permanent AF, a CHADS2 score > 2, and National Kidney Foundation Kidney Disease Outcomes Quality Initiative CKD stage 3–5. Sixty-one patients fulfilled these criteria, and were divided into those receiving antiplatelet anticoagulation (group A) and those receiving warfarin (group B). The results of laboratory investigations and estimated glomerular filtration rate (GFR) were recorded at months 3, 6, 12, and 18 from treatment initiation. We also recorded the occurrence of serious cardiovascular and neurological events, significant bleeding, and survival beyond 12 years.

Results

Of the 61 patients enrolled, 35 were in group A and 26 were in group B. The mean international normalized ratio (INR) was 1.95 ± 1.01 (goal < 3.0). After adjustment for potential confounding variables, we found that patients in group B had a higher estimated GFR (6.06 ± 2.36 mL per minute, P = 0.01). Over a 12-year observation period, group B patients had significantly (P = 0.013) better survival than group A, with an adjusted hazard ratio for mortality of 0.318 (P = 0.022).

Conclusion

Warfarin therapy may delay deterioration in renal function and improve survival of elderly patients with CKD and AF.

Atrial fibrillation and heart failure in the elderly

Atrial fibrillation (AF) is a common clinical problem in elderly patients and especially in those with heart failure (HF). It is a major risk factor for serious cardiovascular events, such as stroke, HF and premature death. Both the prevalence and incidence of AF increase with age and its prevalence in the United States are estimated at more than 2.2 million, with nearly 75% of patients aged >65 years. Aging-related atrial remodeling with fibrosis, dilation and mitochondrial DNA mutations predispose elderly patients to AF. Current management options for AF, including rate control and anticoagulation therapy, can be successfully applied to the elderly population. New antiarrhythmic and anticoagulation medications such as dronedarone and dabigatran, respectively, can impact the approach to therapy in the elderly. Non-pharmacological options such as catheter-based ablation have also gained prominence and have been incorporated into the guidelines for management of AF. However, more trials in the elderly and very elderly segments are needed to clarify the safety and long-term efficacy of the new treatment options.

Patterns of warfarin use in subgroups of patients with atrial fibrillation: a cross-sectional analysis of 430 general practices in the United Kingdom

BACKGROUND

Despite the proven efficacy of warfarin, its use in patients with Atrial Fibrillation (AF) is reportedly low. We investigated the underuse and overuse of warfarin in the management of AF in general practices in the United Kingdom (UK) against the National Institute of Clinical Excellence (NICE, UK) guidelines whilst seeking to identify subgroups of AF patients to inform efforts to optimise warfarin use.

METHODOLOGY

A retrospective database analysis to determine warfarin prescribing using tree models based on 50,361 patients with AF (classified as low, moderate and high risk of stroke using CHADS2) from 430 general practices in the UK.

RESULTS

Over one-third (37.0%, 4573/12,351) of low risk AF patients were on warfarin, compared with 47.1% (8349/17,709) moderate risk AF patients and 54.9% (11,142/20,301) high risk AF patients. Clinical subgroups (n = 15 low risk subgroups, n = 15 medium risk subgroups, n = 22 high risk subgroups) were identified. Several factors not supported by current guidelines (age, BMI, dementia, gender) were associated with the use of warfarin. Gender and BMI were associated with warfarin use in low and medium risk AF patients but not in high risk AF patients.

CONCLUSION

Whilst NICE guidelines suggest that all high risk AF patients should be on warfarin, half of those at moderate risk should be on warfarin and none of those at low risk should be on warfarin, we found evidence of over and under use of warfarin. Interventions to optimise warfarin therapy tailored to and targeting specific subgroups of AF patients identified by the tree models are required.

Atherosclerosis and thromboembolic risk in atrial fibrillation: focus on peripheral vascular disease

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice. It results in a 5-fold increased risk for stroke and thromboembolism and is associated with a high morbidity and mortality. AF shares several risk factors and pathophysiological features with atherosclerosis. Hence AF is often complicated by a variety of other cardiovascular conditions. Indeed, peripheral vascular disease (PVD) is highly prevalent among AF patients and associates with increased mortality. Inclusion of PVD within stroke risk scoring systems such as the CHA2DS2-VASc score improves risk stratification of AF patients. Of note, PVD has not been previously well documented nor looked for in observational studies or clinical trials. The aim of this present review article is to provide an overview of the association between atherosclerosis (with particular focus on PVD) and AF as well as its complications.

Effectiveness of systematic screening for the detection of atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is a leading cause of morbidity and mortality. Screening for AF in asymptomatic patients has been proposed as a way of reducing the burden of the disease by detecting people who would benefit from prophylactic anticoagulation therapy prior to the onset of symptoms. However, for screening to be an effective intervention it must improve the detection of AF and provide benefit for those who are detected earlier as a result of screening.

OBJECTIVES

The primary objective of this review was to examine whether screening programmes increase the detection of new cases of AF compared to routine practice. The secondary objectives were to identify which combination of screening strategy and patient population is most effective, as well as assessing any safety issues associated with screening, its acceptability within the target population and the costs involved.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, MEDLINE (Ovid) and EMBASE (Ovid) up to March 2012. Other relevant research databases, trials registries and websites were searched up to June 2012. Reference lists of identified studies were also searched for potentially relevant studies and we contacted corresponding authors for information about additional published or unpublished studies that may be relevant. No language restrictions were applied.

SELECTION CRITERIA

Randomised controlled trials, controlled before and after studies and interrupted time series studies comparing screening for AF with routine practice in people aged 40 years and over were eligible. Two authors (PM, CT or MF) independently selected the trials for inclusion.

DATA COLLECTION AND ANALYSIS

Assessment of risk of bias and data extraction were performed independently by two authors (PM, CT). Odds ratios (OR) and 95% confidence intervals (CI) were used to present the results for the primary outcome, which is a dichotomous variable. Since only one included study was identified, no meta-analysis was performed.

MAIN RESULTS

One cluster randomised controlled trial met the inclusion criteria for this review. This study compared systematic screening (by invitation to have an electrocardiogram (ECG)) and opportunistic screening (pulse palpation during a general practitioner (GP) consultation for any reason followed by an ECG if pulse was irregular) to routine practice (normal case finding on the basis of clinical presentation) in people aged 65 years or older. The risk of bias in the included study was judged to be low.Both systematic and opportunistic screening of people over the age of 65 years are more effective than routine practice (OR 1.57, 95% CI 1.08 to 2.26 and OR 1.58, 95% CI 1.10 to 2.29, respectively). The number needed to screen in order to detect one additional case compared to routine practice was 172 (95% CI 94 to 927) for systematic screening and 167 (95% CI 92 to 806) for opportunistic screening. Both systematic and opportunistic screening were more effective in men (OR 2.68, 95% CI 1.51 to 4.76 and OR 2.33, 95% CI 1.29 to 4.19, respectively) than in women (OR 0.98, 95% CI 0.59 to 1.62 and OR 1.2, 95% CI 0.74 to 1.93, respectively). No data on the effectiveness of screening in different ethnic or socioeconomic groups were available. There were insufficient data to compare the effectiveness of screening programmes in different healthcare settings.Systematic screening was associated with a better overall uptake rate than opportunistic screening (53% versus 46%) except in the ≥ 75 years age group where uptake rates were similar (43% versus 42%). In both screening programmes men were more likely to participate than women (57% versus 50% in systematic screening, 49% versus 41% in opportunistic screening) and younger people (65 to 74 years) were more likely to participate than people aged 75 years and over (61% versus 43% systematic, 49% versus 42% opportunistic). No adverse events associated with screening were reported.The incremental cost per additional case detected by opportunistic screening was GBP 337, compared to GBP 1514 for systematic screening. All cost estimates were based on data from the single included trial, which was conducted in the UK between 2001 and 2003.

AUTHORS' CONCLUSIONS

Systematic and opportunistic screening for AF increase the rate of detection of new cases compared with routine practice. While both approaches have a comparable effect on the overall AF diagnosis rate, the cost of systematic screening is significantly more than that of opportunistic screening from the perspective of the health service provider. The lack of studies investigating the effect of screening in other health systems and younger age groups means that caution needs to be exercised in relation to the transferability of these results beyond the setting and population in which the included study was conducted.Additional research is needed to examine the effectiveness of alternative screening strategies and to investigate the effect of the intervention on the risk of stroke for screened versus non-screened populations.

Atrial fibrillation in the 21st century: a current understanding of risk factors and primary prevention strategies

Atrial fibrillation (AF) is the most common arrhythmia worldwide, and it has a significant effect on morbidity and mortality. It is a significant risk factor for stroke and peripheral embolization, and it has an effect on cardiac function. Despite widespread interest and extensive research on this topic, our understanding of the etiology and pathogenesis of this disease process is still incomplete. As a result, there are no set primary preventive strategies in place apart from general cardiology risk factor prevention goals. It seems intuitive that a better understanding of the risk factors for AF would better prepare medical professionals to initially prevent or subsequently treat these patients. In this article, we discuss widely established risk factors for AF and explore newer risk factors currently being investigated that may have implications in the primary prevention of AF. For this review, we conducted a search of PubMed and used the following search terms (or a combination of terms): atrial fibrillation, metabolic syndrome, obesity, dyslipidemia, hypertension, type 2 diabetes mellitus, omega-3 fatty acids, vitamin D, exercise toxicity, alcohol abuse, and treatment. We also used additional articles that were identified from the bibliographies of the retrieved articles to examine the published evidence for the risk factors of AF.

A simple score for predicting paroxysmal atrial fibrillation in acute ischemic stroke

BACKGROUND AND PURPOSE

Our aim in this study was to investigate factors associated with paroxysmal atrial fibrillation (PAF) in acute stroke patients and to develop a risk score to predict the presence of PAF.

METHODS

We retrospectively enrolled patients with acute ischemic stroke within 24h of onset between June 2006 and April 2008. Patients with sustained AF were excluded. Patients were divided into two groups according to the presence of PAF: the PAF group or the non-PAF group. The clinical factors associated with PAF were investigated. Furthermore, we devised a new risk score to predict the presence of PAF.

RESULTS

There were 215 patients enrolled. The PAF group had 32 (14.9%) patients. Multivariate logistic regression analysis demonstrated that NIHSS score≥8 (OR, 4.2; 1.38-12.88), left atrial size≥3.8 cm (OR, 4.8; 1.65-13.66), mitral valvular disease (OR, 7.5; 2.17-25.90), and plasma BNP level≥144 pg/ml (OR, 12.8; 4.12-40.00) were independent factors associated with PAF. We developed a risk score from these variables (total score 0 to 5): NIHSS score≥8 (1 point); left atrial size≥3.8 cm (1 point); mitral valvular disease (1 point); and BNP level≥144 pg/ml (2 points). The frequency of PAF was 0% with a score of 0, 4% with a score of 1, 14% with a score of 2, 26% with a score of 3, 50% with a score of 4 and 100% with a score of 5

CONCLUSION

Our simple score can predict the presence of PAF during hospitalization in acute ischemic stroke.

Sex differences in clinical presentation, severity and outcome of stroke: results from a hospital-based registry

BACKGROUND AND PURPOSE

Sex related differences in cardiovascular disease and stroke are issues of increasing interest. The aim of this study was to evaluate for sex differences in clinical presentation, severity of stroke and outcome in a population of patients admitted to 4 public and 1 private hospitals in three different regions of Italy.

METHODS

All hospital admissions for ischemic and haemorrhagic stroke (ICD-IX code 434 and 431 respectively) between January 1st and December 31st, 2011 at five different hospitals located in three different regions of Italy: Milan (North), Rome and Perugia (Center), and Palermo (South) have been recorded and sex-differences have been evaluated.

RESULTS

A total of 1272 stroke patients were included in the analysis: 1152 ischemic and 120 haemorrhagic strokes, 567 women and 705 men. Compared to men, women were significantly older (mean age 75.2 SD 13.7 vs 71.5 SD 12.5 years, P<0.001) and their stroke severities at onset, measured by NIHSS, were also compared to men (10 SD 8 vs 8 SD 7, P<0.001). Female sex was associated with a worse functional prognosis measured by modified Rankin Scale score (mRS≥3), as well as in-hospital mortality, without reaching statistical significance. There were no observed significant differences between sexes regarding the number of patients treated with thrombolytic therapy. Analysis of the distribution of risk factors between sexes showed a prevalence of atrial fibrillation in women (29% vs 21%, P=0.003).

CONCLUSIONS

Both stroke severity and functional outcome were worse in women.

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.

Epidemiology of arrhythmias and conduction disorders in older adults

Normal aging is associated with a multitude of changes in the cardiovascular system, including decreased compliance of blood vessels, mild concentric left ventricular hypertrophy, an increased contribution of atrial contraction to left ventricular filling, and a higher incidence of many cardiac arrhythmias, both bradyarrhythmias and tachyarrhythmias. Conduction disorders also become more common with age, and may either be asymptomatic, or cause hemodynamic changes requiring treatment. The epidemiology of common arrhythmias and conduction disorders in the elderly is reviewed.

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.