Atrial fibrillation prevalence, incidence and risk of stroke and all-cause death among Chinese

Atrial flutter/fibrillation in patients receiving transcatheter closure of atrial septal defect

BACKGROUND/PURPOSE

Atrial flutter/fibrillation (AFL/Af) is a common late complication in atrial septal defect (ASD) patients even after occluder implantation. We try to delineate the risk factors of persistent AFL/Af.

METHODS

From 1998 to 2010, all patients older than 18 years of age who received ASD occluder implantation in our hospital were enrolled, and their records were retrospectively reviewed. In addition, renin-angiotensin system gene polymorphisms including angiotensinogen gene, A1166C polymorphism on the angiotensin II type I receptor gene, and insertion/deletion (I/D) patterns on the angiotensin-converting enzyme gene were checked using direct sequencing.

RESULTS

A total of 517 patients (male/female 127/390) were enrolled. The mean age of patients receiving occluder deployment was 41.5 ± 14.5 years. Prior to occluder deployment, 3.9% of patients had persistent Af, 3.1% of patients had paroxysmal Af, and 0.8% had AFL. After a follow-up of 1894 patient-years, 3.5% had persistent Af and 1.9% of patients had paroxysmal Af. The greatest risk factors of AFL/Af genesis included age, occluder size, presence of multiple ASDs, and underlying thyroid or mitral valve disorder (p < 0.001, p < 0.001, p = 0.033, p = 0.016, and p = 0.012, respectively). Preoperative AFL/Af status is the most important factor in determining AFL/Af resolution and progression after an intervention. The renin-angiotensin system gene polymorphisms had no association with AFL/Af genesis, and progression or resolution after intervention.

CONCLUSION

AFL/Af is common after ASD occluder implantation, and predisposed by older age, larger and multiple ASDs, and underlying disorders. Preoperative atrial arrhythmia status is the most important predictor of AFL/Af progression or resolution. Renin-angiotensin system gene polymorphisms had no association with AFL/Af.

Different Impacts of Atrial Fibrillation and Cardiac Premature Contractions on the Health-Related Quality of Life in Elderly People: The Yilan Study

Atrial fibrillation (AF) is currently recognized as one of the most common cardiac arrhythmias worldwide, with the increasing prevalence that has been estimated to be as high as 9% among the elderly. Health-related quality of life (HRQoL) has become an important patient-centered health outcome measurement, but the impacts created by AF and other arrhythmias with similar symptoms, such as frequent atrial and ventricular premature contractions (APCs and VPCs, defined as ≥ 3 beats/5 minutes), have not been extensively evaluated. The Yilan Study is a population-based community health survey, which in part aims to evaluate the prevalence and impacts of these arrhythmias on the HRQoL in a community dwelling elderly population. A total of 1,732 citizens from the Yilan, Taiwan, aged 65 years or older (45.8% male) were enrolled and visited at their homes, where HRQoL was measured utilizing the Short Form-12 Health Survey. Each participant's heart rhythm was recorded with an electrocardiographic monitor for 5 minutes. The results disclosed that the prevalence of AF of this aged population was 5.8%, similar to the mean global prevalence. Besides, the prevalence of frequent APCs and frequent VPCs in these elderly people were 7.1% and 5.5%, respectively. After multiple regression analysis, elderly people with AF had lower scores in the physical component of HRQoL, while those elderly people with frequent VPCs had lower scores in the mental component. Ultimately, these findings can provide additional useful and population-specific information about AF, and assist medical professionals in designing more effective strategies for cardiac arrhythmia treatments.

Patient Preferences for Oral Anticoagulation Therapy in Atrial Fibrillation: A Systematic Literature Review

OBJECTIVES

Since the introduction of non-vitamin K antagonist (VKA) oral anticoagulants (NOACs), an additional treatment option, apart from VKAs, has become available for stroke prevention in patients with atrial fibrillation (AF). For various reasons, it is important to consider patients' preferences regarding type of medication, particularly in view of the established relationship between preferences towards treatment, associated burden of treatment, and treatment adherence. This review aimed to systematically analyse the scientific literature assessing the preferences of AF patients with regard to long-term oral anticoagulant (OAC) treatment.

METHODS

We searched the MEDLINE, Scopus and EMBASE databases (from 1980 to 2015), added records from reference lists of publications found, and conducted a systematic review based on all identified publications. Outcomes of interest included any quantitative information regarding the opinions or preferences of AF patients towards OAC treatment, ideally specified according to different clinical or convenience attributes describing different OAC treatment options.

RESULTS

Overall, 27 publications describing the results of studies conducted in 12 different countries were included in our review. Among these, 16 studies analysed patient preferences towards OACs in general. These studies predominantly assessed which benefits (mainly lower stroke risk) AF patients would require to tolerate harms (mainly higher bleeding risk) associated with an OAC. Most studies showed that patients were willing to accept higher bleeding risks if a certain threshold in stroke risk reduction could be reached. Nevertheless, most of the publications also showed that the preferences of AF patients towards OACs may differ from the perspective of clinical guidelines or the perspective of physicians. The remaining 11 studies included in our review assessed the preferences of AF patients towards specific OAC medication options, namely NOACs versus VKAs. Our review showed that AF patients prefer easy-to-administer treatments, such as treatments that are applied once daily without any food/drug interactions and without the need for bridging and frequent blood controls.

CONCLUSION

Stroke risk reduction and a moderate increase in the risk of bleeding are the most important attributes for an AF patient when deciding whether they are for or against OAC treatment. If different anticoagulation options have similar clinical characteristics, convenience attributes matter to patients. In this review, AF patients favour attribute levels that describe NOAC treatment.

Adjuvant Chinese Herbal Products for Preventing Ischemic Stroke in Patients with Atrial Fibrillation

OBJECTIVE

Chinese herbal products (CHPs) are widely used for atrial fibrillation (AF) in Taiwan. We investigated the effect of adjuvant CHPs in preventing ischemic stroke in patients with AF.

METHODS

Taiwanese patients in the Health Insurance Database newly diagnosed with AF during 2000-2011 were enrolled. Medication treatment with/without CHPs was administered within 7 days after the AF diagnosis. The clinical endpoint was an ischemic stroke. The Chi-square test, Fisher's exact test, and Student t test were used to examine differences between the traditional Chinese medicine (TCM) and non-TCM cohorts. Cox proportional hazard regression was used to assess the risk for ischemic stroke between two cohorts.

RESULTS

Three hundred and eleven patients underwent TCM treatment and 1715 patients did not. Compared to non-TCM users, TCM users had a lower incidence of stroke (12.59% vs. 1.93%, respectively) and lower risk of stroke [CHA2DS2-VASc score = 0-2 (hazard ratio = 0.20; 95% confidence interval = 0.06-0.65)]. Compared to non-TCM users, the stroke risk was significantly lower in TCM users with AF who were female or younger than 65 years, but not in males, people more than 65 years old, or people with comorbidities. Compared to TCM users, non-TCM users who received conventional treatment had a higher ischemic stroke risk. The risk for AF-related hospitalization was significantly lower in TCM users (0.64%) than in non-TCM users (38.1%).

CONCLUSIONS

Users of TCM with AF have a lower risk of new-onset ischemic stroke. Therefore, adjuvant CHP therapy may have a protective effect and may be used in AF patients to prevent ischemic stroke.

The Predictive Role of Inflammatory Biomarkers in Atrial Fibrillation as Seen through Neutrophil-Lymphocyte Ratio Mirror

Atrial fibrillation (AF) is the most common arrhythmia and is responsible for significant disease burden worldwide. Current evidence has suggested that systemic inflammatory response plays a crucial role in the initiation, maintenance, and progression of AF. So, recent efforts have been directed in search of measurable inflammatory biomarkers as additional tools in severity and prognosis assessment of AF. A simple, and easily obtainable, inflammatory marker is the neutrophil-lymphocyte ratio (NLR), which has shown good performance in preliminary studies as a potential prognostic biomarker in patients with AF. In this work, we performed a thorough review of clinical studies that evaluated the role of C-reactive protein (CRP), interleukin-6 (IL-6), and NLR as predictors of outcomes in AF. We gave a particular emphasis on the NLR because it is a simpler, widely available, and inexpensive biomarker.

Percutaneous closure of the left atrial appendage for stroke prevention in atrial fibrillation: an alternative to lifelong anticoagulation?

Atrial fibrillation is an important risk factor for thromboembolic stroke and it significantly increases the risk of stroke. The left atrial appendage (LAA) is the most common site of thrombus formation in nonvalvular atrial fibrillation, and the recent applications of percutaneous LAA closure devices offer a promising alternative for patients who are unable to tolerate lifelong anticoagulation. Critical care nurses who understand the procedures and are familiar with the various devices used for LAA closure will be well prepared to provide optimum care and appropriate education for these patients.

Adverse cardiovascular effects of nitrogen-containing bisphosphonates in patients with osteoporosis: A nationwide population-based retrospective study

BACKGROUND

Bisphosphonates (BPs) are a class of medications used for the treatment of osteoporosis. Nitrogen-containing BPs (N-BPs) are more potent than non-nitrogenous BPs in terms of their effects on osteoporosis. We examined the effects of N-BPs on osteoporosis in patients included in a large population-based cohort study.

METHODS

Based on the National Health Insurance Research Database of Taiwan, we identified 1258 patients with osteoporosis who had received N-BP treatment from 2005 through 2010.

RESULTS

During the retrospective observation period, N-BP users had significantly higher incidence rates of hypertension, acute ischemic stroke, atrial fibrillation (Af), and congestive heart failure (CHF), and lower rates of hyperlipidemia than patients who did not use N-BPs. Overall, N-BP users had a higher incidence of cardiovascular events at the end of the follow-up period. After adjustment for age, sex, and comorbidities, the risk of developing cardiovascular events was significantly high for patients using N-BPs. Patients who received N-BP therapy also had a higher risk of Af and CHF than those who did not during the five-year follow-up period.

CONCLUSION

We provide evidence that patients with osteoporosis using N-BP therapy have an increased risk of CHF and Af. This potential risk should be weighed against the reduction in the risk of osteoporotic fractures.

Atrial fibrillation in women: epidemiology, pathophysiology, presentation, and prognosis

Atrial fibrillation (AF) is the most common sustained arrhythmia in women and men worldwide. During the past century, a range of risk factors has been associated with AF, severe complications from the arrhythmia have been identified, and its prevalence has been increasing steadily. Whereas evidence has accumulated regarding sex-specific differences in coronary heart disease and stroke, the differences between women and men with AF has received less attention. We review the current literature on sex-specific differences in the epidemiology of AF, including incidence, prevalence, risk factors, and genetics, and in the pathophysiology and the clinical presentation and prognosis of patients with this arrhythmia. We highlight current knowledge gaps and areas that warrant future research, which might advance understanding of variation in the risk factors and complications of AF, and ultimately aid more-tailored management of the arrhythmia.

Hormone replacement therapy and risk of atrial fibrillation in Taiwanese menopause women: A nationwide cohort study

Hormone replacement therapy (HRT) is associated with risk of vascular disease. The association between atrial fibrillation (AF), vascular events, and different HRTs, including estradiol and conjugated equine estrogens (CEE), has been controversial in previous studies. Thus, we conducted a retrospective cohort study to investigate these associations. Female patients (>45 years old) first diagnosed with menopause were enrolled from National Health Insurance Research Dataset (1998–2008). Cox regression analysis estimated risk of new-onset AF, stroke, and major adverse cardiac events (MACE) after exposure to estradiol or CEE. Of 5489 females (mean age = 55 years) enrolled, 1815 treated with estradiol and 3674 treated with CEE. Incidence per 10³ person-years of AF, stroke, and MACE in CEE vs estradiol patients was 2.23 vs. 0.92, 14.0 vs. 9.09, and 15.55 vs. 10.47. As compared with patients treated with estradiol, those treated with CEE had a significantly higher incidence of AF, stroke, and MACE. The adjusted hazard ratios for each category were 1.96, 1.30, and 1.26, respectively. The significant results remained similar, even after use of propensity-score-matched strategy. In conclusion, CEE was associated with a higher risk of AF, stroke, and MACE than estradiol in menopausal females. Further exploration of underlying mechanisms is necessary.

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.

Individualized approaches to thromboprophylaxis in atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide. The prevalence of AF in persons older than 55 years is at least 33.5 million globally and is predicted to more than double in the next half-century. Anticoagulation, heart rate control, and heart rhythm control comprise the 3 main treatment strategies in AF. Anticoagulation is aimed at preventing debilitating stroke, systemic embolism, and associated mortality. Historically, anticoagulation in AF was achieved with a vitamin K antagonist such as warfarin, which is supported by evidence demonstrating reduced incident stroke and all-cause mortality. However, warfarin has unpredictable pharmacokinetics with many drug-drug interactions that require regular monitoring to ensure patients remain in the therapeutic anticoagulant range. Non-vitamin K antagonist oral anticoagulants including dabigatran, rivaroxaban, apixaban, and edoxaban provide a possible solution to these issues with their more predictable pharmacokinetics, rapid onset of action, and greater specificity. Results from large randomized, controlled trials indicate that these agents are at least noninferior to warfarin in prevention of stroke. These trials also demonstrate a consistently lower incidence of intracranial hemorrhage, almost always all life-threatening bleeds, and many forms of major bleeds with the possible exception of gastrointestinal and some other forms of mucosal bleeding, compared with warfarin. Patients with AF are a heterogeneous population with diverse risk of stroke and bleeding, and different subgroups respond differently to anticoagulation. Important clinical questions have arisen regarding optimal anticoagulation drug selection in distinct populations such as those with renal impairment, older age, coronary artery disease, and heart failure as well as those at particularly high risk for bleeding or thromboembolism. In this review, treatment strategies in AF management are discussed in the context of different individual subgroups of patients.

Atrial Fibrillation is Associated With Morphine Treatment in Female Breast Cancer Patients: A Retrospective Population-Based Time-Dependent Cohort Study

We investigated the relationship between morphine treatment and the risk of atrial fibrillation (AF) in female patients with breast cancer. We identified a malignancy cohort of 73,917 female breast cancer patients without an AF history before the date of breast cancer diagnosis between 2000 and 2010 by using the Longitudinal Health Insurance Database for Catastrophic Illness Patients in Taiwan. This malignancy cohort was divided into morphine and comparison cohorts comprising 18,671 and 55,246 patients, respectively, and the incidences of newly diagnosed AF were calculated. We used the Cox proportional hazard model with time-dependent exposure covariates to estimate the risk of AF. The effect of morphine was assessed through multivariable Cox proportional hazard regression controlling for age, the Charlson comorbidity index (CCI) score, and the use of bisphosphonates and paclitaxel. Compared with nonmorphine users, patients who received morphine exhibited a 4.37-fold (95% CI = 3.56-5.36) increase in the risk of developing AF. The risk of AF increased as the CCI score increased, but decreased in patients with tamoxifen treatment. This risk is especially significant in current morphine users of all ages and with low CCI score. AF risk increased as the duration of morphine use lengthened (P for trend <0.0001). The incidence of AF in female breast cancer patients in Taiwan is associated with morphine, but prevented by tamoxifen treatment.

Optimization Of Stroke Prophylaxis Strategies In Nonvalvular AF -Drugs, Devices Or Both?

Atrial fibrillation (AF) is the most common cardiac arrhythmia with the prevalence increasing over time. AF probably afflicts ≥2% of worldwide adult population and increases with age.[1-3] In the Framingham Heart Study, the lifetime risk of having at least one episode of AF for 40-year-old men and women was 26% and 23% respectively.[4].

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

Background

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

Methods

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

Results

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

Conclusions

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

Risk of bleeding and stroke with oral anticoagulation and antiplatelet therapy in patients with atrial fibrillation in Taiwan: a nationwide cohort study

Background

Data on the use of oral anticoagulation (OAC) and antiplatelet therapy and the risk of bleeding and stroke amongst Asian patients with atrial fibrillation (AF) are limited. We investigated the risks of bleeding and stroke with use of oral anticoagulation (OAC) and antiplatelet therapy as mono- or combination therapy, in patients with AF from a Chinese nationwide cohort study.

Methods

We studied a cohort of 10384 patients (57.2% men, age 67.8 ± 13.2 yrs) between 1999 and 2010 from the National Health Insurance Research Database in Taiwan. Records of prescriptions were obtained during follow-up. The main outcome was a recurrent stroke during the follow-up period. Time-dependent Cox proportional hazards models were used for this analysis.

Results

We documented 1009 events for bleeding, as well as 224 hemorrhagic stroke and 1642 ischemic stroke events during a median 3.2 (interquartile range, 1.05-6.54) years’ follow-up. Compared with warfarin users, patients with antiplatelet therapy had a lower risk of bleeding (adjusted relative risk [RR], 0.59, 95% confidence interval [CI], 0.49-0.71, p<0.001) whilst combination therapy had a non-statistically significant higher bleeding risk (RR, 1.33, 95%, 0.91-1.94, p = 0.20). Patients on antiplatelet monotherapy had a similar risk for ischemic stroke compared with OAC (RR 1.05, 95% CI, 0.89-1.25, p = 0.50), whilst those on combination therapy had a significantly higher risk (RR 1.90, 95% CI, 1.34-2.70, p<0.001).

Conclusion

In a national representative cohort, antiplatelet therapy had no significant difference in ischemic stroke risk to warfarin. For bleeding, aspirin had a lower risk compared to warfarin. This may reflect poor anticoagulation control, highlighting important missed opportunities for improved stroke prevention, especially in countries where anticoagulation management is suboptimal.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Atrial fibrillation incidence and risk factors in relation to race-ethnicity and the population attributable fraction of atrial fibrillation risk factors: the Multi-Ethnic Study of Atherosclerosis

PURPOSE

We studied incident atrial fibrillation (AF) in the prospective community-based Multi-Ethnic Study of Atherosclerosis (MESA). Reportedly, non-Hispanic blacks (NHBs) have a lower AF burden compared with their non-Hispanic white (NHW) counterparts. Information on the epidemiology of AF in Hispanic and Asian populations is much more limited.

METHODS

We excluded participants with a history of AF at enrollment. A total of 6721 MESA participants were monitored for the first AF event ascertained according to hospital discharge International Classification of Diseases, Ninth Revision, codes. Age- and sex-adjusted incidence rates (IRs) of AF were calculated per 1000 person-years of observation. IR ratios were calculated using NHWs as the reference group. Age- and sex-adjusted population attributable fractions (PAFs) of established modifiable AF risk factors were ascertained.

RESULTS

In the MESA cohort, 47.2% was male; at baseline, 25.7% had hypertension; 12.5% had diabetes. Three hundred five incident hospitalized AF events occurred over a mean follow-up of 7.3 years. Age- and sex-adjusted IRs and IR ratios showed that overall AF incidence was significantly lower among Hispanics, NHBs and Chinese compared with NHWs (all P < .001). Among participants 65 years of age or greater, Hispanics, Chinese, and blacks had significantly lower AF incidence than NHWs (all P ≤ .01), but IRs were similar among participants under age 65 years. The PAF for smoking was 27% among NHBs but lower among other race-ethnic groups. Among NHWs, the PAF for hypertension was 22.2%, but this was higher among NHBs (33.1%), Chinese (46.3%), and Hispanics (43.9%).

CONCLUSIONS

Overall, the incidence of hospitalized AF was significantly lower in Hispanics, NHBs, and Chinese than in NHWs. A larger proportion of AF events appear to be attributable to hypertension among nonwhite populations compared with NHWs.

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.

Hyperuricemia and incident atrial fibrillation in a normotensive elderly population in Taiwan

BACKGROUND AND AIM

Atrial fibrillation (AF) is an important cardiovascular disease in the elderly. The association between hyperuricemia and AF is unclear. Therefore, we aimed to investigate the prospective relationship between uric acid and development of AF in a nationally representative cohort of elderly people.

METHODS AND RESULTS

A total of 1485 elderly people (age ≥ 65 yrs) from the Elderly Nutrition and Health Survey in Taiwan (1999-2000) were without AF on "electrocardiography" at baseline. Incident AF events (International Classification of Diseases, Ninth Revision, Clinical Modification, ICD-9-CM: 427.31) were identified using data from the National Health Insurance Dataset. Hyperuricemia was defined as levels of uric acid >7.0 mg/dL in men and 6.0 mg/dL in women. A Cox proportional hazards model was used to evaluate the association between hyperuricemia and incident AF. The follow-up period was from 1999 to 2000 to 2008. During the follow-up period (median: 9.16 yrs), 90 AF events occurred (44 in men and 46 in women). Older age, elevated systolic blood pressure, being an ex-smoker, and high uric acid were positively associated with incident AF. Hyperuricemia was positively associated with incident AF in normotensive (age-adjusted hazard ratio (HR): 2.65 and 95% confidence intervals: 1.05-6.69), but not in (1.20:0.74-1.94) hypertensive individuals (systolic blood pressure ≥130 or diastolic blood pressure ≥85 or using hypertensive medicine). A significant association between hyperuricemia and AF (3.78; 1.24-11.59) remained after adjusting for other potential confounders among normotensive older persons.

CONCLUSION

Hyperuricemia is associated with the development of AF in elderly people with normal blood pressure.

Global epidemiology of atrial fibrillation

Atrial fibrillation (AF) is a major public health burden worldwide, and its prevalence is set to increase owing to widespread population ageing, especially in rapidly developing countries such as Brazil, China, India, and Indonesia. Despite the availability of epidemiological data on the prevalence of AF in North America and Western Europe, corresponding data are limited in Africa, Asia, and South America. Moreover, other observations suggest that the prevalence of AF might be underestimated-not only in low-income and middle-income countries, but also in their high-income counterparts. Future studies are required to provide precise estimations of the global AF burden, identify important risk factors in various regions worldwide, and take into consideration regional and ethnic variations in AF. Furthermore, in response to the increasing prevalence of AF, additional resources will need to be allocated globally for prevention and treatment of AF and its associated complications. In this Review, we discuss the available data on the global prevalence, risk factors, management, financial costs, and clinical burden of AF, and highlight the current worldwide inadequacy of its treatment.

Acute myocardial infarction in patients with atrial fibrillation with a CHA2DS2-VASc score of 0 or 1: a nationwide cohort study

BACKGROUND

The risk of acute myocardial infarction (AMI) in patients with atrial fibrillation (AF) with a CHA2DS2-VASc score of 0 (for men) or 1 (for women) has not been previously investigated.

OBJECTIVE

The objective of the present study was to compare the risk of AMI in AF and non-AF subjects with a low (0 or 1) CHA2DS2-VASc score.

METHODS

By using the National Health Insurance Research Database in Taiwan, we identified 7254 men with AF (with a CHA2DS2-VASc score of 0) and 4860 women with AF (with a CHA2DS2-VASc score of 1). For each study patient, 1 age-, sex-, and CHA2DS2-VASc score-matched subject without AF was randomly selected to constitute the control group (n = 12,114). The clinical end point was the occurrence of AMI.

RESULTS

During a mean follow-up period of 5.7 ± 3.6 years, 258 patients (1.1%) suffered an AMI, with an annual incidence of 0.29% and 0.10% for patients with and without AF. AF was an independent risk factor of AMI, with an adjusted hazard ratio (HR) of 2.93 (95% confidence interval 2.21-3.87; P < .001). The risk of AMI was higher in men with AF than in women with AF, with a hazard ratio of 2.24 (95% confidence interval 1.61-3.11; P < .001) after adjustment for age and other comorbidities.

CONCLUSION

In patients with a CHA2DS2-VASc score of 0 or 1, AF was an independent risk factor of AMI. The risk of AMI was higher in men with AF than in women with AF. Cardiovascular risk prevention should be performed as part of the holistic management of AF to minimize the risks of AMI associated with AF.

Continuation of dabigatran therapy in "real-world" practice in Hong Kong

BACKGROUND

Dabigatran, an oral direct thrombin inhibitor, possesses several advantages over warfarin that can in principle simplify the management of stroke prevention in atrial fibrillation (AF). Nonetheless it remains unclear whether these advantages can translate to clinical practice and encourage long-term therapy. The objective was to describe long-term dabigatran therapy for stroke prevention in AF and to identify risk factors for discontinuation of therapy.

METHODS AND RESULTS

We studied 467 consecutive Chinese patients (72 ± 11 years, male: 53.8%) with a mean CHA2DS2-VASc score of 3.6 prescribed dabigatran for stroke prevention in AF from March 2010 to September 2013. Over a mean follow-up of 16 months, 101 patients (21.6%) permanently discontinued dabigatran. The mean time-to-discontinuation was 8 months. The most common reason for discontinuation was dyspepsia (30.7%), followed by other adverse events (17.8%) such as minor bleeding (8.9%), major gastrointestinal bleeding (7.9%), and intracranial hemorrhage (1%). Other reasons included dosing frequency (5.9%), fear of side effects (4.0%), lack of laboratory monitoring (1.0%), and cost (1.0%). Multivariable analysis revealed that low baseline estimated glomerular filtration rate (p = 0.02), absence of hypertension (p = 0.01), and prior use of a proton-pump inhibitor (p = 0.02) and H2-receptor blocker (p = 0.01) were independent predictors of drug discontinuation. In addition, there were altogether 9 ischemic strokes (1.5%/years), 3 intracranial hemorrhages (0.5%/year), and 24 major gastrointestinal bleedings (4.1%/year).

CONCLUSION

Dabigatran discontinuation is very common amongst Chinese AF patients. This reveals a management gap in the prevention of stroke in AF.

Stroke: morbidity, risk factors, and care in taiwan

Stroke is the third leading cause of death and the most common cause of complex disability in Taiwan. The annual age-standardized mortality rate of stroke is steadily decreasing between 2001 and 2012. The average years of potential life lost before age 70 for stroke is 13.8 years, ranked the fifth in the cause of death. Its national impact is predicted to be greater accompany aging population. The most common type of stroke was ischemic stroke in Taiwan. Small vessel occlusion was the majority of ischemic strokes subtype. Age, gender, hypertension, diabetes hyperlipidemia, obesity, atrial fibrillation, and smoking were important contributory factors to stroke morbidity. The standard treatment for acute ischemic stroke in Taiwan is providing the intravenous thrombolysis with recombinant tissue plasminogen activator (IV tPA) therapy for ischemic stroke patients within 3 hours of symptom onset. However, the rate of IV tPA therapy for patients with acute ischemic stroke is still low in Taiwan. Therefore, improving the public awareness of stroke warning signs and act on stroke and improving in-hospital critical pathway for thrombolysis would be the most important and urgent issues in Taiwan. To improve acute stroke care quality, a program of Breakthrough Series-Stroke activity was conducted from 2010 to 2011 and stroke centers were established in the medical centers. For the prevention of stroke, it was successful to increased annual smoke cessation rate through the 2009 Tobacco Hazards Prevention Act and decreased obesity rate through a nationwide weight-loss program conducted by Health Promotion Administration from 2011 to 2013 in Taiwan.

Risk of stroke and intracranial hemorrhage in 9727 Chinese with atrial fibrillation in Hong Kong

BACKGROUND

Current risk schemes to predict ischemic stroke and intracranial hemorrhage (ICH) in atrial fibrillation (AF) are derived primarily using a Caucasian population.

OBJECTIVE

The purpose of this study was to describe the risk of ischemic stroke and ICH in a large contemporary "real world" cohort of Chinese AF patients in Hong Kong with detailed long-term follow-up.

METHODS

This observational study used a hospital-based cohort of Chinese patients with nonvalvular AF.

RESULTS

Among 9727 patients with nonvalvular AF (age 76.9 ± 12.5 years, 52.1% female), 3881 patients (39.9%) did not receive antithrombotic therapy, 3934 patients (40.4%) were taking aspirin, and 1912 (19.7%) were taking warfarin. After mean follow-up of 3.19 years, 847 patients (21.8%) without antithrombotic therapy developed ischemic strokes (annual risk 9.28%, 95% confidence interval [CI] 8.89%-9.70%). There was a progressively increase in annual risk of ischemic stroke with increasing CHADS2 and CHA2DS2VASc scores. The c-statistics revealed that CHA2DS2-VASc scores (0.525, 95% CI 0.509-0.541, P = .017) was better than CHADS2 scores (0.506, 95% CI 0.490-0.522, P = .584) in predicting ischemic stroke. Use of aspirin and of warfarin were associated with reduced annual risk of ischemic stroke by 18.7% and 52.7%, respectively (P <.05). The annual incidence of ICH in patients taking aspirin and warfarin was 0.77% per year and 0.80% per year, respectively. The adjusted net clinical benefit favored warfarin over aspirin or no therapy for almost all Chinese AF patients CHA2DS2-VASc score ≥1.

CONCLUSION

Chinese AF patients are at high risk for ischemic stroke. Analysis of the net clinical benefit favors the use of warfarin over aspirin or no therapy for stroke prevention in a broad range of Chinese AF patients.

Cost-effectiveness of dabigatran etexilate for the prevention of stroke and systemic embolism in atrial fibrillation in Taiwan

BACKGROUND

Economic evaluation of dabigatran, a new anti-antithrombotic agent, is done mostly in Western countries. It remains to be seen whether dabigatran will be cost effective in a practice environment where warfarin is significantly underused and the costs of both warfarin and international normalized ration INR monitoring are cheap.

METHODS

We performed a cost-effectiveness analysis with a Markov model to evaluate the value of dabigatran to prevent stroke and systemic embolism in patients with atrial fibrillation (AF) in Taiwan. Dabigatran was given through sequential dosing, where patients<80 years old received 150 mg of dabigatran twice a day and the dosage was reduced to 110 mgs for patients ≥ 80 years old. Dabigatran was compared with warfarin under two scenarios: the "real-world adjusted-dose warfarin" assuming all AF patients eligible for warfarin were given the medication and maintained at the INR observed in routine clinical practice in Taiwan, and the "real-world prescribing behaviour" similar to the treatment with antithrombotics in real-world practice in Taiwan, where eligible patients could receive warfarin, aspirin, or no treatment.

RESULTS

The percentage of AF patients who received warfarin, aspirin or no treatment in Taiwan was 16%, 62% and 22%, respectively. The event rates of ischemic stroke per 100 patient-years were 4.5, 8.0, and 6.0 for sequential dabigatran, real-world prescribing behaviour and real-world warfarin use, respectively. The incremental cost-effectiveness ratio was $280 US per quality-adjusted-year (QALY) in the real-world prescribing scenario and $10,551 US/QALY in real-word warfarin use.

CONCLUSIONS

Dabigatran was highly cost-effective in a clinical practice setting where warfarin has been significantly underused.

Stroke in Atrial Fibrillation - Long-term Follow-up of Cardiovascular Events

The incidence of atrial fibrillation (AF) was around 1.5 per 1000 person-years in Taiwan. Systemic thromboembolism is the most severe complication of AF. Risk stratification and adequate thromboembolism prophylaxis is the cornerstone of treatment in AF patients. The CHA2DS2-VASc score is powerful in selecting "truly low-risk" patients who are not necessary to receive anticoagulation therapies. It is also useful in predicting thromboembolic events and mortality for patients undergoing AF ablation. Recently, more and more biomarkers and imaging parameters were reported to be associated with adverse events in AF patients. How could these biomarkers and imaging tools change the current strategy of stroke prevention in AF deserves further investigations.

Outcomes for people with atrial fibrillation in an Australian national audit of stroke care

BACKGROUND

Atrial fibrillation is associated with poorer outcomes poststroke. It is unclear how the quality of stroke care in hospitals influences outcomes in these patients.

AIMS

The study aims to compare outcomes in stroke patients with and without atrial fibrillation and identify hospital processes of care associated with poor outcomes.

METHODS

Data were collected using retrospective, consecutive medical record audits from participating hospitals in the 2009 and 2011 National Stroke Foundation acute services audit program. Patient characteristics, stroke severity, and hospital management data were compared for those with and without atrial fibrillation. Multiple regression analyses for outcomes of in-hospital death, dependency at discharge (modified Rankin Score 3-5), and discharge destination were undertaken, adjusted for patient clustering by hospital.

RESULTS

Atrial fibrillation status was known for 5473 (80%) cases; 2049 had atrial fibrillation. Atrial fibrillation was independently associated with in-hospital mortality (aOR 1.46, 95% CI 1.06, 2.02). Management on a stroke unit (aOR 0.57, 95% CI 0.40, 0.80) and having a swallow assessment within 24 h (aOR 0.71, 95% CI 0.51, 0.98) were associated with increased survival among all stroke types, as was receiving aspirin within 48 h poststroke (aOR 0.65, 95% CI 0.44, 0.97), for patients with an ischemic stroke. Stroke patients with atrial fibrillation were less likely to receive important processes of care associated with reduced mortality.

CONCLUSIONS

Hospital processes of care can influence outcomes in stroke patients with atrial fibrillation. The greater in-hospital mortality experienced by stroke patients with atrial fibrillation may be attenuated by admission to a stroke unit, and for ischemic stroke, early administration of aspirin.

Areca nut chewing and risk of atrial fibrillation in Taiwanese men: a nationwide ecological study

BACKGROUND

Areca nut chewing is associated with the risk of obesity, metabolic syndrome, hypertension, and cardiovascular mortality. Although a few case reports or case series have suggested the link between areca nut chewing and cardiac arrhythmias, information about the relationship between areca nut chewing and atrial fibrillation (AF) is lacking. Thus, a nationwide ecological study was conducted to investigate this.

METHODS

Two national datasets, the nationwide population-based 2005 Taiwan National Health Insurance Research dataset (NHIRD) and the 2005 National Health Interview Survey (NHIS), were used for analyses. The clinical characteristics, inhabited area and medical histories for 375,360 eligible males were retrieved from the 2005 NHIRD. Health related behaviors including areca nut chewing, cigarette smoking, infrequent vegetable eating, and exercise habit were collected from the 2005 NHIS. The prevalence of AF and the areca nut chewing rate were evaluated by multivariate analysis.

RESULTS

Of the 375,360 males (mean age, 44 years old), 1,326 (0.35%) were diagnosed with AF. The higher areca nut chewing rate, the higher prevalence rate of AF in Taiwan (Spearman correlation coefficient r=0.558, p=0.007). After adjusting for other covariates, the current areca nut chewing rate was found to be independently associated with the prevalence of AF. The adjusted odd ratio for areca nut chewing was 1.02 (95% CI=1.00-1.04) in risk of AF prevalence.

CONCLUSIONS

Areca nut chewing is independently associated with the prevalence of AF in Taiwanese men. However, further exploration of the underlying mechanisms is necessary.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.