Symptoms and functional status of patients with atrial fibrillation: state of the art and future research opportunities

Fibrosis independent atrial fibrillation in older patients is driven by substrate leukocyte infiltration: diagnostic and prognostic implications to patients undergoing cardiac surgery

Background

The objectives of the study were to characterize and quantify cellular inflammation and structural remodeling of human atria and correlate findings with molecular markers of inflammation and patient surrogate outcome.

Methods

Voluntary participants undergoing heart surgery were enrolled in the study and blood samples were collected prior to surgery, and right atrium samples were harvested intraoperatively. Blood samples were analyzed by flow cytometry and complete blood counts. Atrial samples were divided for fixed fibrosis analysis, homogenized for cytokine analysis and digested for single cell suspension flow cytometry.

Results

A total of 18 patients were enrolled and samples assessed. Isolated cells from the atria revealed a CD45+ population of ~ 20%, confirming a large number of leukocytes. Further characterization revealed this population as 57% lymphocytes and 26% monocyte/macrophages (MoΦ), with the majority of the latter cells being classical (CD14++/CD16−). Interstitial fibrosis was present in 87% of samples and correlated significantly with patient age. Older patients (> 65) had significantly more atrial fibrosis and cellular inflammation. AFib patients had no distinguishing feature of atrial fibrosis and had significantly greater CD45+ MoΦ, increased expression of MMP9 and presented with a significant correlation in length of stay to CCL-2/MCP-1 and NLR (neutrophil-to-lymphocyte ratio).

Conclusion

Atrial fibrosis is correlated with age and not determinate to AFib. However, severity of atrial leukocyte infiltration and markers of matrix degradation are determinant to AFib. This also correlated with CCL2 (or MCP-1) and NLR-indicative of marked inflammation. These data show the potential importance of diagnostic and prognostic assessments that could inform clinical decision making in regard to the intensity of AFib patient management.

Atrial Fibrillation in Middle Eastern Arabs and South Asians: Summary of Published Articles in the Arabian Gulf

Seven studies are summarized herein focusing on different aspects of Atrial fibrillation (AF) in two unique ethnicities for which there is very limited literature published before; Middle Eastern Arabs and South Asians, using data from a national registry of cardiovascular diseases in Qatar over a 20-years period (1991-2010). These studies shed light upon important aspects of AF presentations and outcomes in these two ethnicities, thereby enriching the world literature on AF. In the process, several novel observations were reported and new questions were raised that warrant further investigations.

Characteristics of Atrial Fibrillation Patients with a Family History of Atrial Fibrillation

Background

Family history has been shown to be associated with increased risk of atrial fibrillation (AF). However, the specific AF characteristics that travel with a family history have not yet been elucidated. The purpose of this study was to determine whether a family history of AF is associated with specific patient characteristics in a worldwide, remote cohort.

Methods

From the Health eHeart Study, an internet-based prospective cohort, we performed a cross-sectional analysis of AF participants who reported their family history and completed questionnaires regarding their medical conditions and AF symptoms. We assessed demographics, cardiovascular comorbidities, and AF symptom characteristics in AF participants with and without a family history of AF.

Results

In multivariable analysis of 5,884 participants with AF (mean age 59.9 ± 14.5, 59% male, 92% white), female sex (odds ratio [OR]=1.35, 95% CI, 1.17-1.54, p<0.0001) and birth in the U.S. (OR=2.54, 95% CI, 2.12-3.05, p<0.0001) were independently associated with having a family history of AF. Having a family history of AF was also more commonly associated with symptoms of shortness of breath (OR=1.40, 95% CI, 1.07-1.82, p=0.014), chest pain, pressure, or discomfort (OR=1.95, 95% CI, 1.22-3.13, p=0.0052), and feeling generally "off" about oneself (OR=1.84, 95% CI, 1.27-2.67, p=0.0013).

Conclusions

Patients with a family history of AF are more likely to be female, be US-born, and experience symptoms of AF, suggesting underlying mechanistic differences between those with and without family history of AF.

Health-Related Quality of Life and Associated Factors in Patients with Atrial Fibrillation: An Integrative Literature Review

Atrial fibrillation (AF) is a common cardiac arrhythmia associated with poor health-related quality of life (HRQoL). However, the factors influencing HRQoL in patients with AF are not well understood. The purpose of integrative review was to investigate the factors affecting HRQoL in patients with AF based on the six domains of Ferrans and colleagues’ HRQoL model. A total of 23 relevant articles published between January 2000 and March 2018 were identified using four databases and analyzed in this study. Our review showed that the HRQoL in patients with AF was consistently lower than both healthy individuals and patients with other cardiovascular diseases. The most common factor associated with HRQoL in patients with AF was anxiety-specific to AF in the symptoms domain, followed by frequency and severity of symptoms and the New York Heart Association functional class. This study highlights that monitoring and assessing patients’ symptoms is vital for improving HRQoL in patients with AF. Disease-specific and cross-culturally validated tools can allow healthcare professionals to provide tailored interventions for patients with AF.

Risk Factors for Atrial Fibrillation in People With Type 1 Diabetes: An Observational Cohort Study of 36,258 Patients From the Swedish National Diabetes Registry

OBJECTIVE

This study identified variables associated with increased risk of atrial fibrillation in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We performed a cohort study of people with type 1 diabetes from the Swedish National Diabetes Registry followed up between 1 January 2001 and 31 December 2013. Median follow-up was 9.7 years (interquartile range 5.2-13.0). The association between potential risk factors and incident atrial fibrillation was investigated using adjusted Cox regression. To compare the impact of each risk factor, the gradient of risk per 1 SD was estimated.

RESULTS

In this cohort of 36,258 patients with type 1 diabetes, 749 developed atrial fibrillation during follow-up. Older age, male sex, renal complications, increased BMI and HbA_1c, coronary artery disease, heart failure, and heart valve disease increased the risk of atrial fibrillation. Age, signs of renal dysfunction with macroalbuminuria, and decreasing estimated glomerular filtration rate were associated with the highest gradient of risk for atrial fibrillation. High blood pressure, severe obesity (BMI >35 kg/m²), and elevated levels of HbA_1c (>9.6%) were associated with increased risk, but no associations were found with hyperlipidemia or smoking.

CONCLUSIONS

The most prominent risk factors for atrial fibrillation in people with type 1 diabetes were older age, cardiovascular comorbidities, and renal complications, while obesity, hypertension, and hyperglycemia had more modest affects.

Atrial Fibrillation Symptoms and Sex, Race, and Psychological Distress: A Literature Review

BACKGROUND

Atrial fibrillation (AF) symptoms are a major component of treatment decisions for patients with AF and impact quality of life and functional ability yet are poorly understood.

OBJECTIVE

This review aimed to determine what is known about the prevalence of symptoms and the association of symptoms to AF characteristics, psychological distress, sex, and race.

METHODS

We performed a structured review of AF symptoms as of March 2016 using PubMed, EMBASE, and CINAHL and reference searches of retrieved articles. Full-text, published, peer-reviewed, English-language articles were examined. Articles were included if they reported original research data on symptom prevalence and type among patients with AF.

RESULTS

The 3 most common symptoms were dyspnea, palpitations, and fatigue. The results suggested that, although AF characteristics are not a significant predictor of symptoms, tachycardia, female sex, race, and psychological distress have a positive association to symptoms.

CONCLUSIONS

There is a scarcity of research examining symptoms in AF. Furthermore, the inconsistency in measurement methods and the failure to include diverse populations in AF research make it difficult to draw definitive conclusions from the current literature. Given the prevalence of AF in the United States and the impact of symptoms on quality of life and healthcare use, further research examining predictors of symptoms and interventions to alleviate symptoms is crucial.

Life's Simple 7 Approach to Atrial Fibrillation Prevention

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

Association of sex, age and education level with patient reported outcomes in atrial fibrillation

BACKGROUND

In atrial fibrillation (AF), there are known sex and sociodemographic disparities in clinical outcomes such as stroke. We investigate whether disparities also exist with respect to patient-reported outcomes. We explored the association of sex, age, and education level with patient-reported outcomes (AF-related quality of life, symptom severity, and emotional and functional status).

METHODS

The PaTH AF cohort study recruited participants (N = 953) with an AF diagnosis and age ≥ 18 years across 4 academic medical centers. We performed longitudinal multiple regression with random effects to determine if individual characteristics were associated with patient-reported outcomes.

RESULTS

Women reported poorer functional status (β - 2.23, 95% CI: -3.52, - 0.94) and AF-related quality of life (β - 4.12, 95% CI: -8.10, - 0.14), and higher symptoms of anxiety (β 2.08, 95% CI: 0.76, 3.40), depression (β 1.44, 95% CI: 0.25, 2.63), and AF (β 0.29, 95% CI: 0.08, 0.50). Individuals < 60 years were significantly (p < 0.05) more likely to report higher symptoms of depression, anxiety, and AF, and poorer AF-related quality of life. Lack of college education was associated with reporting higher symptoms of AF (β 0.42, 95% CI: 0.17, 0.68), anxiety (β 1.86, 95% CI: 0.26, 3.45), and depression (β 1.11, 95% CI: 0.15, 2.38), and lower AF-related quality of life (β - 4.41, 95% CI: -8.25, - 0.57) and functional status.

CONCLUSION

Women, younger adults, and individuals with lower levels of education reported comparatively poor patient-reported outcomes. These findings highlight the importance of understanding why individuals experience AF differently based on certain characteristics.

Role of Geriatric Syndromes in the Management of Atrial Fibrillation in Older Adults: A Narrative Review

OBJECTIVES

Atrial fibrillation (AF) is common in older adults and associated with increased risk of cardiovascular events including thromboembolism. However, less is known about its association with noncardiovascular events, especially geriatric syndromes and conditions such as dementia, depression, impaired physical function, polypharmacy, falls, and poor quality of life. This review aims to help healthcare professionals integrate the special needs of older adults into their management of AF.

DESIGN

Nonsystematic review. A literature search on published articles on AF and geriatric syndromes and conditions was performed using the electronic databases MEDLINE, EMBASE and SCOPUS, and DARE until December 2017. Non-English articles were excluded.

SETTINGS AND PARTICIPANTS

Older adults with and without AF from different settings.

MEASURES

Various cognitive, mood, and functional measurements were used in these studies. In studies regarding polypharmacy, the Beers or PRISCUS criteria were used to identify inappropriate medications. In quality of life measurements studies, instruments like Medical Outcomes Study Short Form 36 and Atrial Fibrillation Quality of Life questionnaire were used.

RESULTS

This literature review finds that AF has a substantial association with geriatric syndromes and conditions and that AF is a risk factor for the development of geriatric syndromes and conditions. Evidence is limited regarding the potential benefit of long-term treatment of AF in lowering the risk of developing geriatric syndromes and conditions.

CONCLUSIONS/IMPLICATIONS

Considering the impact of AF on cardiovascular outcomes and geriatric syndromes and conditions in older adults, healthcare professionals need to consider these complex dynamics while managing AF in older adults. An individual approach to AF management is needed in older adults with multiple comorbidity and polypharmacy that may help lower the risk of disease-disease, disease-drug, and drug-drug interactions. Special consideration needs to be given to patients' cognitive and functional impairment and ability to adhere to therapy.

Atrial fibrillation symptom clusters and associated clinical characteristics and outcomes: A cross-sectional secondary data analysis

BACKGROUND

Symptom clusters among adults with atrial fibrillation have previously been identified but no study has examined the relationship between symptom clusters and outcomes.

AIMS

The purpose of this study was to identify atrial fibrillation-specific symptom clusters, characterize individuals with each cluster, and determine whether symptom cluster membership is associated with healthcare utilization.

METHODS

This was a cross-sectional secondary data analysis of 1501 adults from the Vanderbilt Atrial Fibrillation Registry with verified atrial fibrillation. Self-reported symptoms were measured with the University of Toronto Atrial Fibrillation Severity Scale. We used hierarchical cluster analysis (Ward's method) to identify clusters and dendrograms, pseudo F, and pseudo T-squared to determine the ideal number of clusters. Next, we used regression analysis to examine the association between cluster membership and healthcare utilization.

RESULTS

Males predominated (67%) and the average age was 58.4 years. Two symptom clusters were identified, a Weary cluster (3.7%, n=56, fatigue at rest, shortness of breath at rest, chest pain, and dizziness) and an Exertional cluster (32.7%, n=491, shortness of breath with activity and exercise intolerance). Several sociodemographic and clinical characteristics varied by symptom cluster group membership, including age, gender, atrial fibrillation type, body mass index, comorbidity status, and treatment strategy. Women were more likely to experience either cluster ( p<0.001). The Weary cluster was associated with nearly triple the rate of emergency department utilization (incident rate ratio [IRR] 2.8, p<0.001) and twice the rate of hospitalizations (IRR 1.9, p<0.001).

CONCLUSION

We identified two symptom clusters. The Weary cluster was associated with a significantly increased rate of healthcare utilization.

Atrial Fibrillation Symptom Perception

Atrial fibrillation (AF), the most common cardiac arrhythmia, is associated with a significantly increased risk of ischemic stroke, heart failure, and death. AF is a heterogenous disease both in terms of the pathophysiologic mechanisms that lead to the disease, and in terms of symptom presentation. Although most patients with AF perceive symptoms, their symptom experience is highly variable. The purpose of this paper is to review the: 1) epidemiology and pathophysiology of AF, 2) symptoms associated with AF, and 3) implications for clinical practice based on disparate symptom perception.

Relation of Body Mass Index to Symptom Burden in Patients withAtrial Fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with significant morbidity and increased mortality. As body mass index (BMI) is increasingly recognized as an important risk factor for the development of AF, we tested the hypothesis that BMI modulates symptomatic AF burden. Cross-sectional data collected from 1,382 patients in the Vanderbilt AF Registry were analyzed. AF severity was assessed using the Toronto atrial fibrillation severity scale (AFSS). BMI was categorized according to World Health Organization guidelines and patients were grouped according to their present AF treatment regimen: no treatment (n = 185), rate control therapy with atrioventricular nodal blocking agents (n = 351), rhythm control with antiarrhythmic drugs (n = 636), and previous AF ablation (n = 210). Patients with BMI >35 kg/m2 had higher AFSS scores than those with BMI <30 kg/m2 in the rate control (43.57 vs 38.21: p = 0.0057), rhythm control (46.61 vs 41.08: p = 1.6 × 10-4), and ablation (44.01 vs 39.02: p = 0.047) groups. Inunivariate linear models, BMI was associated with an increase in the AFSS score in the rate control (0.27, 95% confidence interval [CI] 0.05 to 0.5, p = 0.02), rhythm control (0.38, 95% CI 0.21 to 0.56, p = 2.49 × 10-5), and ablation (0.38, 95% CI 0.03 to 0.73, p = 0.03) groups. The association remained significant in the rhythm control groups after adjusting for age, gender, race, and comorbidities (0.29, 95% CI 0.11 to 0.49, p = 0.002). In conclusion, increasing BMI was directly associated with patient reported measures of AF symptom severity, burden, and quality of life. This was most significant in patients treated with rhythm-control strategies.

Atrial fibrillation symptom profiles associated with healthcare utilization: A latent class regression analysis

BACKGROUND

Symptoms drive healthcare use among adults with atrial fibrillation, but limited data are available regarding which symptoms are most problematic and which patients are most at-risk. The purpose of this study was to: (1) identify clusters of patients with similar symptom profiles, (2) characterize the individuals within each cluster, and (3) determine whether specific symptom profiles are associated with healthcare utilization.

METHODS

We conducted a cross-sectional secondary data analysis of 1,501 adults from the Vanderbilt Atrial Fibrillation Registry. Participants were recruited from Vanderbilt cardiology clinics, emergency department, and in-patient services. Subjects included in our analysis had clinically verified atrial fibrillation and a completed symptom survey. Symptom and healthcare utilization data were collected with the University of Toronto Atrial Fibrillation Severity Scale. Latent class regression analysis was used to identify symptom clusters, with clinical and demographic variables included as covariates. We used Poisson regression to examine the association between latent class membership and healthcare utilization.

RESULTS

Participants were predominantly male (67%) with a mean age of 58.4 years (±11.9). Four latent classes were evident, including an Asymptomatic cluster (N = 487, 38%), Highly Symptomatic cluster (N = 142, 11%), With Activity cluster (N = 326, 25%), and Mild Diffuse cluster (N = 336, 26%). Highly Symptomatic membership was associated with the greatest rate of emergency department visits and hospitalizations (incident rate ratio 2.4, P < 0.001).

CONCLUSIONS

Clinically meaningful atrial fibrillation symptom profiles were identified that were associated with increased rates of emergency department visits and hospitalizations.

Contemporary management of patients undergoing atrial fibrillation ablation: in-hospital and 1-year follow-up findings from the ESC-EHRA atrial fibrillation ablation long-term registry

Aims

The ESC-EHRA Atrial Fibrillation Ablation Long-Term registry is a prospective, multinational study that aims at providing an accurate picture of contemporary real-world ablation for atrial fibrillation (AFib) and its outcome.

Methods and results

A total of 104 centres in 27 European countries participated and were asked to enrol 20-50 consecutive patients scheduled for first and re-do AFib ablation. Pre-procedural, procedural and 1-year follow-up data were captured on a web-based electronic case record form. Overall, 3630 patients were included, of which 3593 underwent an AFib ablation (98.9%). Median age was 59 years and 32.4% patients had lone atrial fibrillation. Pulmonary vein isolation was attempted in 98.8% of patients and achieved in 95-97%. AFib-related symptoms were present in 97%. In-hospital complications occurred in 7.8% and one patient died due to an atrioesophageal fistula. One-year follow-up was performed in 3180 (88.6%) at a median of 12.4 months (11.9-13.4) after ablation: 52.8% by clinical visit, 44.2% by telephone contact and 3.0% by contact with the general practitioner. At 12-months, the success rate with or without antiarrhythmic drugs (AADs) was 73.6%. A significant portion (46%) was still on AADs. Late complications included 14 additional deaths (4 cardiac, 4 vascular, 6 other causes) and 333 (10.7%) other complications.

Conclusion

AFib ablation in clinical practice is mostly performed in symptomatic, relatively young and otherwise healthy patients. Overall success rate is satisfactory, but complication rate remains considerable and a significant portion of patients remain on AADs. Monitoring after ablation shows wide variations. Antithrombotic treatment after ablation shows insufficient guideline-adherence.

Symptom Clusters in Adults With Chronic Atrial Fibrillation

BACKGROUND

Symptom clusters have not previously been explored among individuals with atrial fibrillation of any type.

OBJECTIVE

The purpose of this study is to determine the number of symptom clusters present among adults with chronic atrial fibrillation and to explore sociodemographic and clinical factors potentially associated with cluster membership.

METHODS

This was a cross-sectional secondary data analysis of 335 Australian community-dwelling adults with chronic (recurrent paroxysmal, persistent, or permanent) atrial fibrillation. We used self-reported symptoms and agglomerative hierarchical cluster analysis to determine the number and content of symptom clusters present.

RESULTS

There were slightly more male (52%) than female participants, with a mean (SD) age of 72 (11.25) years. Three symptom clusters were evident, including a vagal cluster (nausea and diaphoresis), a tired cluster (fatigue/lethargy, weakness, syncope/dizziness, and dyspnea/breathlessness), and a heart cluster (chest pain/discomfort and palpitations/fluttering). We compared patient characteristics among those with all the symptoms in the cluster, those with some of the symptoms in the cluster, and those with none of the symptoms in the cluster. The only statistically significant differences were in age, gender, and the use of antiarrhythmic medications for the heart cluster. Women were more likely to have the heart symptom cluster than men were. Individuals with all of the symptoms in the heart cluster were younger (69.6 vs 73.7 years; P = .029) than those with none of the symptoms in the heart cluster and were more likely to be on antiarrhythmic medications.

CONCLUSION

Three unique atrial fibrillation symptom clusters were identified in this study population.

Development and Validation of the AFImpact: An Atrial Fibrillation-Specific Measure of Patient-Reported Health-Related Quality of Life

BACKGROUND

Improvement in health-related quality of life is a key therapeutic goal of disease management in atrial fibrillation (AF).

OBJECTIVES

To describe the development of the AFImpact, an AF-specific health-related quality-of-life patient-reported outcome measure.

METHODS

Development and validation of the AFImpact comprised a qualitative stage, consisting of a literature review and concept elicitation interviews (91 patients with AF), item generation, and cognitive debriefing (30 patients with AF), and a quantitative stage, consisting of evaluation of the instrument's psychometric properties (313 patients with AF). Preliminary responsiveness to change was assessed in 118 patients undergoing cardioversion.

RESULTS

On the basis of the literature review and concept elicitation interviews, 75 items were generated. Factor analyses guided a reduction to 18 items. Three domains were confirmed: vitality (7 items), emotional distress (8 items), and sleep (3 items). The 18-item AFImpact demonstrated high item convergent and discriminant validity. Cronbach α coefficients showed high internal consistency reliability. Test-retest reliability of individual items in stable patients (n = 33) was satisfactory, with intraclass correlation coefficients ranging from 0.61 to 0.86. All three AFImpact domain scores differentiated patients who reported different levels of overall health, thereby supporting known-groups validity. Scores for each item improved after cardioversion, with effect sizes ranging from -0.19 to -0.65.

CONCLUSIONS

Psychometric evaluations support the reliability and validity of the AFImpact as a patient-reported outcome instrument to measure the impact of AF, with preliminary results in patients undergoing cardioversion supporting responsiveness to change.

Exposure-Based Therapy for Symptom Preoccupation in Atrial Fibrillation: An Uncontrolled Pilot Study

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Patients often experience a range of symptoms resulting in a markedly reduced quality of life, and commonly show symptom preoccupation in terms of avoidance and control behaviors. Cognitive behavior therapy (CBT) has been shown to improve symptom burden and quality of life in other somatic disorders, but has never been evaluated in patients with AF. The purpose of this study was to evaluate the potential efficacy and feasibility of an AF-specific CBT protocol in an uncontrolled pilot study. The study included 19 patients with symptomatic paroxysmal (intermittent) atrial fibrillation who were assessed pre- and posttreatment and at 6-month follow-up. The CBT lasted 10 weeks and included exposure to physical sensations similar to AF symptoms, exposure to avoided situations or activities, and behavioral activation. We observed large within-group improvements on the primary outcome AF-specific quality of life measurement AFEQT posttreatment (Cohen's d = 1.54; p < . 001) and at 6-month follow-up (d = 1.15; p < . 001). We also observed improvements in self-reported frequency and severity of AF symptoms. All participants completed the treatment and treatment satisfaction was high. This study demonstrates the potential efficacy and feasibility of a novel CBT approach to reduce symptoms and increase quality of life in AF patients.

Symptom challenges after atrial fibrillation ablation

BACKGROUND

It is unclear what symptom challenges occur during the recovery phase after atrial fibrillation (AF) ablation.

OBJECTIVES

This longitudinal pilot study explored the patient perspective of the first six months following an AF ablation.

METHODS

Telephone interviews and questionnaires were used with 20 patients at baseline, at 1, 3, and 6 months after AF ablation. Telephone interview data were analyzed using content analysis. Longitudinal outcomes were analyzed using repeated measures analysis of variance (ANOVA).

RESULTS

Mean age was 65 ± 7 years and the sample was 55% female. The severity and duration of fatigue was the most concerning symptom. Patient expectations differed from providers' expectations. Recovery was a much slower process than patients expected.

CONCLUSIONS

Patients struggled to manage symptoms after AF ablation. A more accurate understanding of the symptom challenges following AF ablation could lead to development of more realistic education to improve patient self-management.

Risk of atrial fibrillation in people with type 1 diabetes compared with matched controls from the general population: a prospective case-control study

BACKGROUND

Type 1 diabetes is associated with an increased risk of developing several cardiovascular complications. To our knowledge, the independent association between type 1 diabetes and atrial fibrillation has not been studied.

METHODS

We did a prospective case-control study of individuals with type 1 diabetes in the Swedish National Diabetes Registry who were each matched with five controls for age, sex, and county of residence who were randomly selected from the Swedish Population Register. Cases of atrial fibrillation were obtained from the Swedish National Patient Registry.

FINDINGS

We followed up 36 258 patients with type 1 diabetes and 179 980 controls between Jan 1, 2001, and Dec 31, 2013. Median follow-up was 9·7 years (IQR 5·2-13·0) for patients and 10·2 years (5·7-13·0) for controls. 749 (2%) individuals with type 1 diabetes and 2882 (2%) controls were diagnosed with atrial fibrillation, with an adjusted hazard ratio (HR) of 1·13 (95% CI 1·01-1·25; p=0·029) in men and 1·50 (1·30-1·72; p<0·0001) in women (p=0·0019 for interaction). The excess risk of atrial fibrillation in individuals with type 1 diabetes increased with worsening glycaemic control and renal complications. Among individuals with normoalbuminuria, no excess risk of atrial fibrillation was noted in men with type 1 diabetes who had HbA_1c lower than 9·7% (<83 mmol/mol) or in women with type 1 diabetes who had HbA_1c lower than 8·8% (<73 mmol/mol).

INTERPRETATION

Compared with the general population, the risk of atrial fibrillation in men with type 1 diabetes was slightly raised, whereas for female patients it was 50% higher. The risk of atrial fibrillation in people with type 1 diabetes increased with renal complications and poor glycaemic control.

FUNDING

Novo Nordisk Foundation, Swedish State (ALF agreement), Swedish Research Council (SIMSAM), Swedish Heart and Lung Foundation, Swedish Diabetes Foundation, Diabetes Wellness.

Feasibility and Usability of a Mobile Application to Assess Symptoms and Affect in Patients with Atrial Fibrillation: A Pilot Study

Background

Atrial fibrillation (AF) is the most prevalent arrhythmia leading to hospital admissions. The majority of patients with AF report symptoms that are believed to be associated with the arrhythmia. The symptoms related to AF traditionally are collected during a clinic visit that is influenced by biases associated with recalling the experience over a limited period of time.

Purpose

We designed this pilot study to assess the usability and feasibility of a mobile application to assess symptoms in patients with AF.

Methods

We designed a mobile application (miAfib) to assess symptoms (chest pain, palpitation, shortness of breath, fatigue, dizziness/lightheadedness), positive affect (happy, excited, content) and negative affect (worried, angry, sad) on multiple occasions throughout the day based on iOS platform. We performed a four-week feasibility trial to examine user adherence, acceptance and experiences with the mobile application. We administered questionnaires to assess factors affecting usage and self-reported acceptance of the application based on a five-point Likert scale with zero representing strongly disagree and 5 representing strongly disagree with.

Results

We included ten patients with paroxysmal and persistent AF. The mean number of completed assessments each day was 2.81 ± 1.59 with 94.7% of days with at least one assessment. The users found the application easy to use (4.75±0.46), intended to use it in the future (4.37±1.06) and found it easy to integrate into daily routine (4.5±1.07).

Conclusion

In this pilot study, we found participants in this four-week trial reliably used the application and were able to use the app to report their daily symptoms and affect regularly. Participants reported that they found the application easy to use and would consider using the application in the future.

Older Adults at Risk for Atrial Fibrillation Lack Knowledge and Confidence to Seek Treatment for Signs and Symptoms

Early detection of atrial fibrillation (AF) is crucial for averting AF-related stroke and heart failure, but treatment is delayed when AF is not recognized. The critical need for early detection and treatment requires education to promote AF awareness. Knowledge deficits, attitudes, and beliefs about AF that should be addressed to improve awareness and reduce treatment-seeking delay in older adults at risk for developing AF have not been well documented. The purpose of this study was to describe knowledge, treatment-seeking attitudes, and beliefs about AF in adults ⩾ 65 years old and identify demographic characteristics associated with knowledge, attitudes, and beliefs. Patients with no history of AF recruited from an academic medical center were interviewed using the Knowledge, Attitudes, and Beliefs about Atrial Fibrillation Survey. Data were analyzed using descriptive statistics and independent t tests. Participants (N = 180) were 63% male with a mean age of ±3.± 6.0 years, and 52% held ⩾ 4-year college degree. About one third could not identify common symptoms of AF including palpitations (31%), chest pain (36%), dyspnea (30%), and fatigue (35%). A majority (84%) lacked confidence to recognize AF, and 58% were not sure when they should seek care for AF symptoms. Nearly a third (32%) believed palpitations are always present with AF, and 74% believed that low energy would not be their only symptom of AF. Higher scores for AF Symptom Knowledge (p = .02) were observed in females, and General Knowledge about AF was greater for younger participants (p < .001). Participants lacked knowledge and confidence to aid decision-making for treatment-seeking for symptoms of AF and held inaccurate beliefs about AF that could hinder early treatment-seeking. Programs to promote AF awareness should explain the spectrum of symptoms that may be manifested by AF and include action plans for responding to symptoms.

A review of rate control in atrial fibrillation, and the rationale and protocol for the RATE-AF trial

BACKGROUND AND OBJECTIVE

Atrial fibrillation (AF) is common and causes impaired quality of life, an increased risk of stroke and death as well as frequent hospital admissions. The majority of patients with AF require control of heart rate. In this article , we summarise the limited evidence from clinical trials that guides prescription, and present the rationale and protocol for a new randomised trial. As rate control has not yet been shown to reduce mortality, there is a clear need to compare the impact of therapy on quality of life, cardiac function and exercise capacity. Such a trial should concentrate on the long-term effects of treatment in the largest proportion of patients with AF, those with symptomatic permanent AF, with the aim of improving patient well-being.

DESIGN AND INTERVENTION

The RAte control Therapy Evaluation in permanent Atrial Fibrillation (RATE-AF) trial will enrol 160 participants with a prospective, randomised, open-label, blinded end point design comparing initial rate control with digoxin or bisoprolol. This will be the first head-to-head randomised trial of digoxin and beta-blockers in AF.

PARTICIPANTS

Recruited patients will be aged ≥60 years with permanent AF and symptoms of breathlessness (equivalent to New York Heart Association class II or above), with few exclusion criteria to maximise generalisability to routine clinical practice.

OUTCOME MEASURES

The primary outcome is patient-reported quality of life, with secondary outcomes including echocardiographic ventricular function, exercise capacity and biomarkers of cellular and clinical response. Follow-up will occur at 6 and 12 months, with feasibility components to inform the design of a future trial powered to detect a difference in hospital admission. The RATE-AF trial will underpin an integrated approach to management including biomarkers, functions and symptoms that will guide future research into optimal, personalised rate control in patients with AF.

ETHICS AND DISSEMINATION

East Midlands-Derby Research Ethics Committee (16/EM/0178); peer-reviewed publications.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02391337; ISRCTN: 95259705. Pre-results.

Sex differences in health status and rehabilitation outcomes in patients with atrial fibrillation treated with ablation: Results from the CopenHeartRFA trial

Background:

Increased physical capacity after comprehensive rehabilitation in patients with atrial fibrillation (AF) undergoing ablation has been found in the CopenHeartRFA trial. The purpose of this study was to investigate: (a) sex differences in health status, psychological distress and quality of life, (b) sex differences in rehabilitation outcomes and (c) predictors of effect of rehabilitation.

Methods:

We conducted an exploratory analysis of data from the randomized CopenHeartRFA trial, where patients treated with ablation were randomized with 1:1 to comprehensive rehabilitation consisting of a physical exercise program and psycho-educational consultations versus usual care. Sex disparities in health status were tested using Chi-square and t-tests.

Results:

Included were: 151 men (median age 59.25 years) and 59 women (median age 62.5 years). At hospital discharge, women reported lower physical health status compared with men. Among women, significant differences were found in the 6-min walk test [rehabilitation: 496.8 meters (SD 98.5) versus 559.3meters (SD 55.5) and usual care: 521.9 meters (SD 97.8) versus 530.9 meters (SD 102.2), p = 0.01] and exercise time [rehabilitation: 387.6 s (SD 126.0) versus 463.2 s (SD 121.8) and usual care: 353.4 s (SD 145.2) versus 355.8 s (SD 154.8), p < 0.004] and among men in the sit-to-stand test. Significant differences were found in mental health outcomes among men and in quality of life scores among women. Patients with a European Heart Rhythm Association (EHRA) score I-II had a positive effect of rehabilitation.

Conclusion:

The results suggest that sex differences exist in self-reported health after rehabilitation in patients ablated for AF. Patients with an I–II EHRA score seem more likely to gain from the rehabilitation programme compared with those with a III–IV score.

Prospective Assessment of Sex-Related Differences in Symptom Status and Health Perception Among Patients With Atrial Fibrillation

Background

We prospectively assessed sex‐specific differences in health perception, overall symptom status, and specific symptoms in a large cohort of patients with atrial fibrillation.

Methods and Results

We performed a prospective multicenter observational cohort study of 1553 patients with atrial fibrillation. Patients completed questionnaires about personal characteristics, comorbidities, and symptoms on a yearly basis. Mean age was 70±11 years among women and 67±12 years among men. Health perception on a visual analogue scale ranging from 0 to 100 (with higher scores indicating better health perception) was significantly lower in women than in men (70 [interquartile range: 50–80] versus 75 [interquartile range: 60–85]; P<0.0001). More women than men had any symptoms (85.0% versus 68.3%; P<0.0001), palpitations (65.2% versus 44.4%; P<0.0001), dizziness (25.6% versus 13.5%; P<0.0001), dyspnea (35.7% versus 21.8%; P<0.0001), and fatigue (25.3% versus 19.1%; P=0.006). At 1‐year follow‐up, symptoms decreased in both sexes but remained more frequent in women (49.1% versus 32.6%, P<0.0001). In multivariable adjusted longitudinal regression models, female sex remained an independent predictor for lower health perception (ß=−4.8; 95% CI, −6.5 to −3.1; P<0.0001), any symptoms (odds ratio [OR]: 2.6; 95% CI, 2.1–3.4; P<0.0001), palpitations (OR: 2.6; 95% CI, 2.1–3.2; P<0.0001), dizziness (OR: 2.9; 95% CI, 2.1–3.9; P<0.0001), dyspnea (OR: 2.1; 95% CI, 1.6–2.8; P<0.0001), fatigue (OR: 1.6; 95% CI, 1.2–2.2; P=0.0008), and chest pain (OR: 1.8; 95% CI, 1.3–2.6; P=0.001).

Conclusions

Women with atrial fibrillation have a substantially higher symptom burden and lower health perception than men. These relationships persisted after multivariable adjustment and during prospective follow‐up.

Older age and a higher EHRA score allow higher levels of frailty syndrome to be predicted in patients with atrial fibrillation

BACKGROUND

There is no research that evaluates the relationship between the severity of the symptoms of atrial fibrillation (AF), the presence of frailty syndrome and acceptance of the illness.

METHODS

The study included 132 patients aged 72.7 ± 6.73 with diagnosed AF. The severity of the symptoms of AF was determined according to European Heart Rhythm Association (EHRA) guidelines, frailty syndrome was assessed using the Tilburg frailty indicator (TFI) and the acceptance of the illness was assessed using the acceptance of illness scale (AIS). A standard statistical comparison and multiple regression analysis using the stepwise method were performed.

RESULTS

In patients with AF, frailty was 5.31 ± 2.69 (TFI). Frailty syndrome was diagnosed in 59.8% of the AF patients who had a score of 7.17 ± 1.72. A higher level of EHRA score was connected with a smaller degree of the acceptance of the illness p = 0.0000. The multiple regression model indicated that age (p = 0.0009) and the severity of the symptoms (p = 0.0001) are important predictors of frailty syndrome.

CONCLUSIONS

There is a relationship between the presence of frailty syndrome and the intensity of the symptoms and the acceptance of AF. Age and the EHRA score permitted higher levels of frailty syndrome to be predicted.

Reproducibility and Reliability of the Quality of Life Questionnaire in Patients With Atrial Fibrillation

BACKGROUND

Studies have shown the impact of atrial fibrillation (AF) on the patients' quality of life. Specific questionnaires enable the evaluation of relevant events. We previously developed a questionnaire to assess the quality of life of patients with AF (AFQLQ version 1), which was reviewed in this study, and new domains were added.

OBJECTIVE

To demonstrate the reproducibility of the AFQLQ version 2 (AFQLQ v.2), which included the domains of fatigue, illness perception and well-being.

METHODS

We applied 160 questionnaires (AFQLQ v.2 and SF-36) to 40 patients, at baseline and 15 days after, to measure inter- and intraobserver reproducibility. The analysis of quality of life stability was determined by test-retest, applying the Bartko intraclass correlation coefficient (ICC). Internal consistency was assessed by Cronbach's alpha test.

RESULTS

The total score of the test-retest (n = 40) had an ICC of 0.98 in the AFQLQ v.2, and of 0.94 in the SF36. In assessing the intra- and interobserver reproducibility of the AFQLQ v.2, the ICC reliability was 0.98 and 0.97, respectively. The internal consistency had a Cronbach's alpha coefficient of 0.82, compatible with good agreement of the AFQLQ v.2.

CONCLUSION

The AFQLQ v.2 performed better than its previous version. Similarly, the domains added contributed to make it more comprehensive and robust to assess the quality of life of patients with AF.

Selecting symptom instruments for cardiovascular populations

The purpose of this review is to provide a guide for researchers and clinicians in selecting an instrument to measure four commonly occurring symptoms (dyspnea, chest pain, palpitations, and fatigue) in cardiac populations (acute coronary syndrome, heart failure, arrhythmia/atrial fibrillation, and angina, or patients undergoing cardiac interventions). An integrative review of the literature was conducted. A total of 102 studies summarizing information on 36 different instruments are reported in this integrative review. The majority of the instruments measured multiple symptoms and were used for one population. A majority of the symptom measures were disease-specific and were multi-dimensional. This review summarizes the psychometrics and defining characteristics of instruments to measure the four commonly occurring symptoms in cardiac populations. Simple, psychometrically strong instruments do exist and should be considered for use; however, there is less evidence of responsiveness to change over time for the majority of instruments.

Atrial Fibrillation and Declining Physical Performance in Older Adults: The Health, Aging, and Body Composition Study

BACKGROUND

Age is the foremost risk factor for atrial fibrillation (AF), and AF has a rising prevalence in older adults. How AF may contribute to decline in physical performance in older adults has had limited investigation. We examined the associations of incident AF and 4-year interval declines in physical performance at ages 70, 74, 78, and 82 years in the Health, Aging, and Body Composition (Health ABC) Study.

METHODS AND RESULTS

Health ABC is a prospective cohort of community-dwelling older adults (n=3075). The study conducted serial assessments of physical performance with the Health ABC physical performance battery (scored 0-4), grip strength, 2-minute walk distance, and 400-m walking time. Incident AF was identified from the Center for Medicare and Medicaid Services and related to 4-year interval decline in physical performance. After exclusions, the analysis included 2753 Health ABC participants (52% women, 41% black race). Participants with AF had a significantly greater 4-year physical performance battery decline than those without AF at age 70, 74, 78, and 82, with mean estimated decline ranging from -0.08 to -0.10 U (95% confidence interval, -0.18 to -0.01; P<0.05 for all estimates) after multivariable adjustment. Grip strength, walk distance, and walk time similarly showed significantly greater declines at each 4-year age interval in participants with AF.

CONCLUSIONS

In community-based cohort older adults, incident AF was associated with increased risk of decline in physical performance. Further research is essential to identify mechanisms and preventive strategies for how AF may contribute toward declining physical performance in older adults.

A comparison of the CHARGE-AF and the CHA2DS2-VASc risk scores for prediction of atrial fibrillation in the Framingham Heart Study

BACKGROUND

Atrial fibrillation (AF) affects more than 33 million individuals worldwide and increases risks of stroke, heart failure, and death. The CHARGE-AF risk score was developed to predict incident AF in three American cohorts and it was validated in two European cohorts. The CHA2DS2-VASc risk score was derived to predict risk of stroke, peripheral embolism, and pulmonary embolism in individuals with AF, but it has been increasingly used for AF risk prediction. We compared CHARGE-AF risk score versus CHA2DS2-VASc risk score for incident AF risk in a community-based cohort.

METHODS AND RESULTS

We studied Framingham Heart Study participants aged 46 to 94 years without prevalent AF and with complete covariates. We predicted AF risk using Fine-Gray proportional sub-distribution hazards regression. We used the Wald χ(2) statistic for model fit, C-statistic for discrimination, and Hosmer-Lemeshow (HL) χ(2) statistic for calibration. We included 9722 observations (mean age 63.9 ± 10.6 years, 56% women) from 4548 unique individuals: 752 (16.5%) developed incident AF and 793 (17.4%) died. The mean CHARGE-AF score was 12.0 ± 1.2 and the sub-distribution hazard ratio (sHR) for AF per unit increment was 2.15 (95% CI, 99-131%; P < .0001). The mean CHA2DS2-VASc score was 2.0 ± 1.5 and the sHR for AF per unit increment was 1.43 (95% CI, 37%-51%; P < .0001). The CHARGE-AF model had better fit than CHA2DS2-VASc (Wald χ(2) = 403 vs 209, both with 1 df), improved discrimination (C-statistic = 0.75, 95% CI, 0.73-0.76 vs C-statistic = 0.71, 95% CI, 0.69-0.73), and better calibration (HL χ(2) = 5.6, P = .69 vs HL χ(2) = 28.5, P < .0001).

CONCLUSION

The CHARGE-AF risk score performed better than the CHA2DS2-VASc risk score at predicting AF in a community-based cohort.

Regular Expression-Based Learning for METs Value Extraction

Functional status as measured by exercise capacity is an important clinical variable in the care of patients with cardiovascular diseases. Exercise capacity is commonly reported in terms of Metabolic Equivalents (METs). In the medical records, METs can often be found in a variety of clinical notes. To extract METs values, we adapted a machine-learning algorithm called REDEx to automatically generate regular expressions. Trained and tested on a set of 2701 manually annotated text snippets (i.e. short pieces of text), the regular expressions were able to achieve good accuracy and F-measure of 0.89 and 0.86. This extraction tool will allow us to process the notes of millions of cardiovascular patients and extract METs value for use by researchers and clinicians.

Symptoms In Atrial Fibrillation: A Contemporary Review And Future Directions

Atrial fibrillation (AF) is the most prevalent arrhythmia leading to hospital admissions in the United States. The majority of patients with AF report symptoms associated with this condition that can lead to a decrease in health related quality of life (HRQOL) and functional status. Therefore, along with reducing the risk of stroke and mortality, improvements in such symptoms are important therapeutic goals in the management of patients with AF. Our current understanding of how AF and symptoms are linked is hampered by the dominant assessment paradigm, where symptoms thought to be associated with AF are measured at a single point in time (frequently at a clinic visit). Unfortunately, this "static" snapshot does not capture the variability of symptoms and heart rhythm within a person over time and does not shed light on how symptoms are related to heart rhythm. This focused review summarizes current methods for assessing symptoms including generic and AF-specific HRQOL and functional status tools. It also describes gaps in the current assessment paradigm and where future research using mobile applications and digital technology might be able to assist with patient care.

Atrial fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder, and increases in prevalence with increasing age and the number of cardiovascular comorbidities. AF is characterized by a rapid and irregular heartbeat that can be asymptomatic or lead to symptoms such as palpitations, dyspnoea and dizziness. The condition can also be associated with serious complications, including an increased risk of stroke. Important recent developments in the clinical epidemiology and management of AF have informed our approach to this arrhythmia. This Primer provides a comprehensive overview of AF, including its epidemiology, mechanisms and pathophysiology, diagnosis, screening, prevention and management. Management strategies, including stroke prevention, rate control and rhythm control, are considered. We also address quality of life issues and provide an outlook on future developments and ongoing clinical trials in managing this common arrhythmia.

Diagnostic Evaluation and Follow-Up of Patients with Atrial Fibrillation

In this article, a review of the diagnostic evaluation and outpatient follow-up of patients with atrial fibrillation is presented. After exploring details of symptoms, past medical history, quality of life, and physical exam findings, diagnostic tools are then discussed. Furthermore, important considerations after the initial diagnosis and treatment of patients with atrial fibrillation are discussed.

Assessing quality-of-life outcomes in cardiovascular clinical research

The field of quality-of-life (QOL) measurement grew out of attempts in the 1960s and 1970s to connect the ever-increasing levels of public expenditure on technology-based health care for chronic diseases with evidence of the benefits and harms to patients. Most of the concepts, methods, and standards for measuring QOL were derived from psychometrics, but the degree to which current tools adhere to these methods varies greatly. Despite the importance of QOL, patient-reported outcomes are not measured in most cardiovascular clinical trials. Lack of familiarity with QOL measures and their interpretation, and unrealistic expectations about the information these measures can provide, are obstacles to their use. Large clinical trials of revascularization therapy for coronary artery disease and medical treatments for heart failure show small-to-moderate QOL effects, primarily detected with disease-specific instruments. Larger treatment effects, seen in trials of device therapy for heart failure and ablation therapy for atrial fibrillation, have been detected with both generic and disease-specific instruments. A large gap remains between the parameters currently being measured in clinical research and the data needed to incorporate the 'patient's voice' into therapeutic decision-making.

Representation of Functional Status Concepts from Clinical Documents and Social Media Sources by Standard Terminologies

Patient-reported functional status is widely recognized as an important patient-centered outcome that adds value to medical care, research, and quality improvement. Functional status outcomes are, however, not routinely or uniformly collected in the medical record, except in certain small patient populations (e.g. geriatrics, nursing home residents). To utilize patient reported functional status for clinical research and practice, we manually collected 2,763 terms from clinical records and social media sites and modeled them on the widely used Short Form-36 Health Survey. We then examined the coverage of the Unified Medical Language System (UMLS) for these functional status terms through automated mapping. Most terms (85.9%) did not have exact matches in the UMLS. The partial matches were prevalent, however, they typically did not capture the terms' exact semantics. Our study suggests that there is a need to extend existing standard terminologies to incorporate functional status terms used by patients and clinicians.

Fatigue, dyspnea, and intermittent symptoms are associated with treatment-seeking delay for symptoms of atrial fibrillation before diagnosis

BACKGROUND

Delay in seeking treatment for symptoms of atrial fibrillation (AF) at onset results in a missed opportunity for vital early treatment of AF which is important for reducing stroke, tachycardia induced heart failure, and treatment-resistant AF. Little is known about factors that contribute to treatment-seeking delay for symptoms of AF.

PURPOSE

The purpose of this study was to identify factors associated with treatment-seeking delay for symptoms of AF before diagnosis.

METHODS

For this descriptive study, 150 participants with recently detected AF completed structured interviews to collect data about symptoms, symptom characteristics, symptom representation regarding cause, seriousness, controllability of symptoms, responses to symptoms before diagnosis, and time from symptom onset to treatment-seeking. Chi-square analysis was used to identify factors associated with delay (>1 week) versus no delay (⩽1 week) in treatment-seeking after symptom onset.

RESULTS

Participants were 51% female (n=76) with a mean age of 66.5 (standard deviation (SD)±11.1) years. A majority (70%, n=105) delayed treatment-seeking. Factors associated with delay included experiencing fatigue, dyspnea, intermittent symptoms, attributing symptoms to deconditioning, overwork, inadequate sleep, and perceiving symptoms as not very serious and amenable to self-management. Responses such as a wait and see approach, working through symptoms, reporting no fear of symptoms, or attempting to ignore symptoms were associated with delay.

CONCLUSION

Experiencing fatigue, dyspnea and intermittent symptoms produced symptom representations and emotional and behavioral responses associated with treatment-seeking delay. There is a critical need to develop and test educational interventions to increase awareness of the spectrum and characteristics of AF symptoms and appropriate treatment-seeking behaviors.

Geographic variation in the use of catheter ablation for atrial fibrillation among Medicare beneficiaries

BACKGROUND

Catheter ablation for atrial fibrillation is used increasingly in older patients, yet the risks and benefits are not completely understood. With such uncertainty, local medical opinion may influence catheter ablation use.

METHODS

In a 100% sample of Medicare beneficiaries ≥65 years who underwent catheter ablation for atrial fibrillation between January 1, 2007, and December 31, 2009, we investigated variation in use by hospital referral region (HRR) for 20,176 catheter ablation procedures.

RESULTS

Across 274 HRRs, median age was 71.2 years (interquartile range 70.5-71.8), a median of 98% of patients were white, and a median of 39% of patients were women. The median age-standardized prevalence of atrial fibrillation was 77.1 (69.4-84.2) per 1,000 beneficiaries; the median rate of catheter ablation was 3.5 (2.4-4.9) per 1,000 beneficiaries. We found no significant associations between the rate of catheter ablation and prevalence of atrial fibrillation (P = .99), end-of-life Medicare expenditures per capita (P = .09), or concentration of cardiologists (P = .45) but a slight association with Medicare expenditures per capita (linear regression estimate 0.016; 95% CI 0.001-0.031; P = .04). Examined HRR characteristics explained only 2% of the variation in HRR-level rates of catheter ablation (model R(2) = 0.016).

CONCLUSION

The rate of catheter ablation for atrial fibrillation in older patients was low, varied substantially by region, and was not associated with the prevalence of atrial fibrillation, the availability of cardiologists, or end-of-life resource use and was only slightly associated with overall Medicare expenditures per capita.