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

Opportunistic screening for atrial fibrillation by clinical pharmacists in UK general practice during the influenza vaccination season: A cross-sectional feasibility study

BACKGROUND

Growing prevalence of atrial fibrillation (AF) in the ageing population and its associated life-changing health and resource implications have led to a need to improve its early detection. Primary care is an ideal place to screen for AF; however, this is limited by shortages in general practitioner (GP) resources. Recent increases in the number of clinical pharmacists within primary care makes them ideally placed to conduct AF screening. This study aimed to determine the feasibility of GP practice-based clinical pharmacists to screen the over-65s for AF, using digital technology and pulse palpation during the influenza vaccination season.

METHODS AND FINDINGS

Screening was conducted over two influenza vaccination seasons, 2017-2018 and 2018-2019, in four GP practices in Kent, United Kingdom. Pharmacists were trained by a cardiologist to pulse palpate, record, and interpret a single-lead ECG (SLECG). Eligible persons aged ≥65 years (y) attending an influenza vaccination clinic were offered a free heart rhythm check. Six hundred four participants were screened (median age 73 y, 42.7% male). Total prevalence of AF was 4.3%. All participants with AF qualified for anticoagulation and were more likely to be male (57.7%); be older; have an increased body mass index (BMI); and have a CHA2DS2-VASc (Congestive heart failure, Hypertension, Age ≥ 75 years, Diabetes, previous Stroke, Vascular disease, Age 65-74 years, Sex category) score ≥ 3. The sensitivity and specificity of clinical pharmacists diagnosing AF using pulse palpation was 76.9% (95% confidence interval [CI] 56.4-91.0) and 92.2% (95% CI 89.7-94.3), respectively. This rose to 88.5% (95% CI 69.9-97.6) and 97.2% (95% CI 95.5-98.4) with an SLECG. At follow-up, four participants (0.7%) were diagnosed with new AF and three (0.5%) were initiated on anticoagulation. Screening with SLECG also helped identify new non-AF cardiovascular diagnoses, such as left ventricular hypertrophy, in 28 participants (4.6%). The screening strategy was cost-effective in 71.8% and 64.3% of the estimates for SLECG or pulse palpation, respectively. Feedback from participants (422/604) was generally positive. Key limitations of the study were that the intervention did not reach individuals who did not attend the practice for an influenza vaccination and there was a limited representation of UK ethnic minority groups in the study cohort.

CONCLUSIONS

This study demonstrates that AF screening performed by GP practice-based pharmacists was feasible, economically viable, and positively endorsed by participants. Furthermore, diagnosis of AF by the clinical pharmacist using an SLECG was more sensitive and more specific than the use of pulse palpation alone. Future research should explore the key barriers preventing the adoption of national screening programmes.

Atrial Fibrillation With and Without Cardiovascular Risk Factors and Stroke Mortality

Aim: The association between atrial fibrillation (AF) and risk of stroke mortality among men and women without traditional cerebrocardiovascular risk factors (TCVRFs) is unclear. This study aimed to determine whether AF was a risk factor for stroke and total cardiovascular disease mortality among individuals without TCVRFs.

Methods: A total of 90,629 Japanese subjects from the Ibaraki Prefectural Health Study aged 40–79 years, with and without TCVRFs, were studied from 1993 to 2013. Hazard ratios (HRs) were calculated using the Cox proportional hazard regression model stratified by sex and the presence of TCVRFs. Covariates were age, systolic blood pressure, anti-hypertensive medication use, and serum total cholesterol levels. A standard 12-lead electrocardiogram at rest was used to screen AF. Cause-specific mortality was classified according to the International Classification of Disease code.

Results: Compared with participants without AF, multivariable-adjusted hazard ratios (with 95% confidence intervals) for stroke mortality among participants without TCVRFs were 4.3 (1.1–17.8) and 15.0 (5.5–40.8) for men and women with AF, respectively. HRs for total cardiovascular disease mortality were 6.2 (2.8–14.2) for men and 10.7 (4.8–24.1) for women. For participants with TCVRFs, multivariable-adjusted HRs for stroke mortality were 3.1 (2.2–4.6) and 4.3 (2.6–7.3), whereas HRs for total cardiovascular disease mortality were 2.9 (2.2–3.8) and 3.5 (2.4–5.1) for men and women, respectively.

Conclusions: AF was found to be an independent risk factor for stroke and total cardiovascular mortality even in individuals without other TCVRFs.

A self-management support intervention for patients with atrial fibrillation: a randomized controlled pilot trial

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia worldwide. Despite effective treatment, it is characterized by frequent recurrences. Optimal therapeutic management of AF requires active participation and self-management from patients. Two major components of self-management are self-monitoring and sign-and-symptom management. Pulse self-palpation (PSP) is a method of self-monitoring; however, not all AF patients are capable of successfully performing PSP. Due to a lack of interventions on this topic, a nurse-led intervention for patients with AF (PSPAF intervention) was developed to foster self-monitoring and to enhance self-management through PSP. The purpose of this pilot study was to test the acceptability, feasibility, and potential effects of this intervention on the capability of patients' PSP and sign-and-symptom management. Moreover, we aimed at gathering data on the feasibility of applied research methods to aid in the design of future studies.

METHODS

The pilot trial involved 20 adult patients with AF, randomized to an intervention or usual care group. At baseline and during a home visit 3-5 weeks later, we collected data using questionnaires, checklists, field notes, a mobile ECG device, and a diary. Acceptability and feasibility measures were validated through predefined cut-off points. Effect size estimates were expressed as relative risks (RR) and the number needed to treat (NNT).

RESULTS

The PSPAF intervention seemed feasible, but only partly acceptable. There were limitations in terms of potential effectiveness, suitability, addressing participants' willingness to implement its content in daily life, and adherence. Estimations of effect sizes suggest a large effect of the intervention on patients' PSP capability (RR = 6.0; 95% CI = [0.83, 43.3]; NNT = 2.4), but almost no effect on sign-and-symptom management (RR = 1.5; 95% CI = [0.7, 3.1]; NNT = 4.0). The feasibility of applied research methods showed minor limitations on recruitment and participant burden.

CONCLUSIONS

Despite some limitations, the intervention seemed to be applicable and promising. Taking into account the suggestions and amendments we have made, we recommend conducting a full-scale trial to examine the efficacy of the PSPAF intervention.

TRIAL REGISTRATION

This pilot study was registered in the German Clinical Trials Register at September 4, 2017 (Main ID: DRKS00012808).

A Delphi consensus on the management of oral anticoagulation in patients with non-valvular atrial fibrillation in Spain: ACOPREFERENCE study

OBJECTIVE

To evaluate the level of agreement between cardiologists regarding the management of oral anticoagulation (OAC) in patients with non-valvular atrial fibrillation (NVAF) in Spain.

MATERIALS AND METHODS

A two-round Delphi study was performed using an online survey. In round 1, panel members rated their level of agreement with the questionnaire items on a 9-point Likert scale. Item selection was based on acceptance by ≥66.6% of panellists and the agreement of the scientific committee. In round 2, the same panellists evaluated those items that did not meet consensus in round 1.

RESULTS

A total of 238 experts participated in round 1; of these, 217 completed the round 2 survey. In round 1, 111 items from 4 dimensions (Thromboembolic and bleeding risk evaluation for treatment decision-making: 18 items; Choice of OAC: 39 items; OAC in specific cardiology situations: 12 items; Patient participation and education: 42 items) were evaluated. Consensus was reached for 92 items (83%). Over 80% of the experts agreed with the use of DOACs as the initial anticoagulant treatment when OAC is indicated. Panellists recommended the use of DOACs in patients at high risk of thromboembolic complications (CHA2DS2-VASc ≥3) (83%), haemorrhages (HAS-BLED ≥3) (89%) and poor quality of anticoagulation control (SAMe-TT2R2 >2) (76%), patients who fail to achieve an optimal therapeutic range after 3 months on VKA treatment (93%), and those who are to undergo cardioversion (80%). Panellists agreed that the efficacy and safety profile of each DOAC (98%), the availability of a specific reversal agent (72%) and patient's preference (85%) should be considered when prescribing a DOAC. A total of 97 items were ultimately accepted after round 2.

CONCLUSIONS

This Delphi panel study provides expert-based recommendations that may offer guidance on clinical decision-making for the management of OAC in NVAF. The importance of patient education and involvement has been highlighted.

Epicardial Fat Volume as a New Imaging-Based Feature Associated with Risk of Recurrence after Pulmonary Veins Ablation in Atrial Fibrillation

Background: Atrial fibrillation (AF), a common arrhythmia in clinical practice, is associated with a high rate of complications and an increased risk for thromboembolic events. Pulmonary vein ablation is a new therapeutic option to cure AF; however, it remains associated with a high rate of recurrence. In this study we aimed to identify the clinical characteristics and imaging-based features that may predict the risk of recurrence after pulmonary veins ablation in atrial fibrillation.

Materials and method: Twenty-four patients with paroxysmal and persistent AF, who underwent radiofrequency catheter ablation and a 12-month follow-up were included in the study. Group 1 included 8 patients with AF recurrence, and group 2 included 16 patients with no AF recurrence. In all cases, cardiovascular risk factors, ejection fraction, left atrial diameter, atrial volumes, and epicardial fat volume were analyzed.

Results: CT analysis revealed that patients with AF recurrence presented a significantly larger mean index of left atrial volume (59.57 ± 8.52 mL/m2 vs. 49.99 ± 10.88 mL/m2, p = 0.04), right atrial volume (58.94 ± 8.37 mL/m2 vs. 43.21 ± 6.4 mL/m2, p<0.0001), and indexed bi-atrial volume (118.5 ± 15.82 mL/m2 vs. 93.19 ± 16.42 mL/m2, p = 0.005). At the same time, CT analysis of the epicardial adipose tissue volume indicated that patients with AF recurrence have a larger amount of epicardial fat than those without AF recurrence (176.4 ± 100.8 mL vs. 109.8 ± 40.73 mL, p = 0.02).

Conclusion: Left atrial diameter, indexed atrial volumes, and epicardial fat volume may be used as factors to identify patients at risk for developing recurrence after pulmonary vein ablation.

Thrombus in the left atrial appendage in patients with atrial fibrillation treated with non-vitamin K antagonist oral anticoagulants in clinical practice-A multicenter registry

BACKGROUND

The prevalence and predictors of left atrial appendage thrombus (LAAT) in patients with non-valvular atrial fibrillation (AF) who have been treated with non-vitamin K antagonist oral anticoagulants (NOACs) are not well defined. We aimed to assess the occurrence and predictors of LAAT on transesophageal echocardiography (TOE) in patients with non-valvular AF treated with NOACs for at least 3 weeks.

METHODS

Consecutive patients with non-valvular AF who underwent TOE before catheter ablation or electrical cardioversion in three high-reference centers between 2014 and 2018 were included. Patients on apixaban were excluded from the study due to low numbers in this category. All patients received NOACs for at least 3 weeks before TOE.

RESULTS

A total of 1148 patients (female, 38.1%; mean age, 62.1 years) referred to our centers for catheter ablation of AF (52.1%) or electrical cardioversion (47.9%) were included. Patients were on rivaroxaban (51.9%) or dabigatran (48.1%). Preprocedural TOE revealed LAAT in 4.4% of all patients. Multivariable logistic regression analysis showed the CHA2DS2-VASc score ≥2 points (OR = 2.11; 95% CI, 1.15-3.88; P = .0161), non-paroxysmal AF (OR = 6.30; 95% CI, 2.22-17.91; P = .0005), and GFR <60 mL/min/1.73 m² (OR = 2.05; 95% CI, 1.14-3.67; P = .0160) were independent predictors of LAAT in patients treated with NOACs.

CONCLUSIONS

In non-valvular AF patients treated with NOACs, the prevalence of LAAT was 4.4% before electrical cardioversion or ablation. In addition to the CHA2DS2-VASc score, the type of AF and renal function should be considered in the stratification of thromboembolism risk in AF patients and qualification for a preprocedural TOE.

Intensity and Distribution of Patchy Late Gadolinium Enhancement in Left Atrium in Patients With Atrial Fibrillation

Purpose

Late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (MRI) studies were performed on healthy individuals to establish signal intensity thresholds for reproducible left atrial (LA) patchy LGE detection. Using established criteria, differences in LA patchy LGE between healthy volunteers (HV) and patients with atrial fibrillation (AF) or hypertension were analyzed.

Methods

Fifty-three patents with AF (mean age 56 years, 60% men), 25 patients with hypertension and no history of AF (mean age 54 years, 40% men), and 28 HV (mean age 50 years, 52% men) were enrolled in an observational, non-interventional, case-control prospective study. LA patchy LGE quantification was performed using LGE MRI (1.5 T scanner, voxel size 1.25x1.25x2.5 mm) and the custom-built software based on estimation of LA voxel image intensity ratio and comparison with threshold value obtained from HV data.

Results

Based on analysis of healthy individuals' data, the optimal threshold value for the left atrial patchy LGE quantification was determined at 1.38. Patients with AF had a higher extent of LA patchy LGE (9.1 [1.72; 18.58] %) than patients with hypertension (3.81 [0.57; 9.51] %) and HV (0.78 [0.05; 3.5] %). The predominant location of LA patchy LGE in AF was in the pulmonary vein ostia region, in hypertension - LA posterior wall, and in HV - lower part of LA posterior wall. In AF patients, the extent of LA patchy LGE correlated with LA end-diastolic volume (r=0.37) and LA ejection fraction (r=-0.4), in HV - with age (r=0.66) and LA end-diastolic volume (r=0.4).

Conclusion

AF and hypertension are associated with higher extent and different location of LA patchy LGE compared to changes caused by natural aging. The extent of LA patchy enhancement correlates with LA dilatation.

Analysis of Risk Factors Independently Associated with Cognitive Impairment in Patients with Permanent Atrial Fibrillation: A Cross-sectional Observational Study

BACKGROUND AND OBJECTIVE

Atrial Fibrillation (AF) is associated with an increased risk of stroke and development of cognitive impairment. Our cross-sectional study aims to identify risk factors for cognitive impairment in patients with permanent AF.

MATERIALS AND METHODS

212 consecutive outpatients with history of permanent AF lasting more than 1 year were enrolled and the Short Portable Mental Status Questionnaire (SPMSQ) was used to assess cognitive impairment (number of errors ≥5). The type of antithrombotic therapy, the time in therapeutic range (TTR) in case of treatment with warfarin and the degree of heart rate (HR) control (upon Holter ECG monitoring) were also assessed.

RESULTS

ROC curve analysis indicated that TTR was associated with cognitive impairment (AUC 0.85 ± 0.03; 95% CI 0.77-0.88; p < 0.0001). Multivariate logistic regression analysis showed an independent association of previous cerebrovascular or cardiovascular events (OR 7.24, 95% CI 1.37-38.25; p = 0.020), aspirin therapy instead of anticoagulant therapy (OR 24.74, 95% CI 1.27-482.12; p = 0.034), warfarin use with TTR ≤60% (OR 21.71 , 95%CI 4.35-108; p < 0.001) and an average daily HR either <60 bpm or >100 bpm (OR 6.04, 95% 1.09-33.29; p = 0.039) with cognitive impairment.

CONCLUSION

Among patients with permanent AF, cognitive impairment is more frequent in those with inadequate antithrombotic therapy (aspirin therapy instead of anticoagulant therapy) and with suboptimal oral anticoagulation (TTR ≤60%) or heart rate control. Efforts should be made to optimize therapies related to these parameters.

Temporal Trends in Population Rates of Incident Atrial Fibrillation and Atrial Flutter Hospitalizations, Stroke Risk, and Mortality Show Decline in Hospitalizations

BACKGROUND

Hospitalization for nonvalvular atrial fibrillation (NVAF) is common and results in substantial cost burden. Current national data trends for the incidence, stroke risk profiles, and mortality of hospitalization for NVAF and atrial flutter (AFL) are sparse.

METHODS

The Canadian Institute of Health Information Discharge Abstract Database was used to identify patients ≥ 20 years with incident NVAF/AFL (NVAF, ICD-9 code 427.3 or ICD-10 I48) in any diagnosis field from 2006 to 2015 in Canada, except Québec. National and provincial trends in rate over time (rate ratio, 95% confidence interval [CI]) were calculated for age-sex standardized hospitalizations. Trends in stroke risk profiles and in-hospital mortality rates adjusted for stroke risk factors were also calculated.

RESULTS

A total of 578,947 patients were hospitalized with incident NVAF/AFL. The median age was 77 years (interquartile range: 68-84), 82% were ≥ 65 years, 54% were men, 54% had a CHADS2 ≥ 2, and 69% had a CHA2DS2-Vasc ≥ 3. The overall age- and sex-standardized rate of NVAF/AFL hospitalization was 315 per 100,000 population and declined by 2% per year (P < 0.001). There was an annual rate decline in NVAF/AFL hospitalizations in every province. The majority of hospitalized patients are at high risk of stroke, and this risk remained unchanged. The average adjusted in-hospital mortality was 8.80 per 100 patients 95% CI, 8.80-8.81 with a 2% annual decline in rate (P < 0.001).

CONCLUSION

Between 2006 and 2015, we found national and provincial hospitalization rates for incident NVAF/AFL are declining. The majority of patients are at high risk for stroke. In-hospital mortality has declined but remains substantial.

Secondary stroke prophylaxis in atrial fibrillation patients with chronic kidney disease: a nationwide cohort study

AIMS

Oral anticoagulation (OAC) therapy as secondary stroke prophylaxis in atrial fibrillation (AF) patients with chronic kidney disease (CKD) remains unexplored and poses a clinical treatment dilemma. We assessed the long-term risk of thromboembolic events according to post-stroke OAC therapy in AF patients with CKD after their first ischaemic stroke.

METHODS AND RESULTS

We identified Danish AF patients with CKD who presented with first-time ischaemic stroke from 2005 to 2014. Chronic kidney disease was defined as a diagnosis code for CKD before baseline, defined as 100 days after stroke discharge. Post-stroke antithrombotic therapy (OAC therapy and antiplatelet therapy) was identified from prescription claims from discharge to baseline. Cumulative incidences and adjusted hazard ratios (HRs) of thromboembolic events according to post-stroke OAC therapy were examined. Of 1252 AF patients with CKD presenting with ischaemic stroke, 631 (50.4%) patients were on OAC therapy and 621 (49.6%) were on antiplatelet therapy alone at baseline [median age 76 (interquartile range, IQR 71-83) and 80 (IQR 72-86), respectively]. The median follow-up period was 1.9 years (IQR 0.8-3.6). Cumulative incidence rates of thromboembolic events and bleeding showed no significant difference between those on OAC therapy and antiplatelet therapy. The results from the multivariable analysis revealed similar results: thromboembolic risk was not modified by OAC treatment [adjusted HR 0.89, 95% confidence interval (CI) 0.73-1.09] nor was the risk of bleeding (adjusted HR 0.88, 95% CI 0.67-1.17).

CONCLUSION

Oral anticoagulation in patients with CKD and prior stroke was not associated with a reduced risk of recurrent thromboembolic events compared with antiplatelet therapy.

Using Zebrafish to Analyze the Genetic and Environmental Etiologies of Congenital Heart Defects

Congenital heart defects (CHDs) are among the most common human birth defects. However, the etiology of a large proportion of CHDs remains undefined. Studies identifying the molecular and cellular mechanisms that underlie cardiac development have been critical to elucidating the origin of CHDs. Building upon this knowledge to understand the pathogenesis of CHDs requires examining how genetic or environmental stress changes normal cardiac development. Due to strong molecular conservation to humans and unique technical advantages, studies using zebrafish have elucidated both fundamental principles of cardiac development and have been used to create cardiac disease models. In this chapter we examine the unique toolset available to zebrafish researchers and how those tools are used to interrogate the genetic and environmental contributions to CHDs.

Long-term blood pressure trajectories and incident atrial fibrillation in women and men: the Tromsø Study

AIMS

To explore sex-specific associations between long-term individual blood pressure (BP) patterns and risk of incident atrial fibrillation (AF) in the general population.

METHODS AND RESULTS

Blood pressure was measured in 8376 women and 7670 men who attended at least two of the three population-based Tromsø Study surveys conducted in 1986-87, 1994-95, and 2001. Participants were followed for incident AF throughout 2013. Latent mixed modelling was used to identify long-term trajectories of systolic BP and hypertension. Cox regression was used to estimate associations between the identified trajectories and incident AF. Elevated systolic BP throughout the exposure period (1986-2001) independently and differentially increased risk of AF in women and men. In women, having elevated systolic BP trajectories doubled AF risk compared to having persistently low levels, irrespective of whether systolic BP increased, decreased, or was persistently high over time, with hazard ratios of 1.88 (95% confidence interval 1.37-2.58), 2.32 (1.61-3.35), and 1.94 (1.28-2.94), respectively. In men, those with elevated systolic BP that continued to increase over time had a 50% increased AF risk: 1.51 (1.09-2.10). When compared to those persistently normotensive, women developing hypertension during the exposure period, and women and men with hypertension throughout the exposure period had 1.40 (1.06-1.86), 2.75 (1.99-3.80), and 1.36 (1.10-1.68) times increased risk of AF, respectively.

CONCLUSION

Long-term BP and hypertension trajectories were associated with increased incidence of AF in both women and men, but the associations were stronger in women.

Burden of atrial fibrillation and stroke risk among octagenarian and nonagenarian women in Australia

PURPOSE

To determine the prevalence and incidence of atrial fibrillation (AF) among older Australian women from 2000 to 2015, determine factors associated with AF, and to calculate risk of stroke at the time of AF diagnosis.

METHODS

This is a retrospective analysis of 6671 women of the 1921-1926 birth cohort of the Australian Longitudinal Study on Women's Health, linked to data from hospital admissions to identify AF and National Death Index to determine date of death. Yearly prevalence and incidence proportions of AF, and stroke risk using CHA2DS2-VA scheme, were calculated. Factors associated with AF were assessed using logistic regression.

RESULTS

From 2000 to 2015, a total of 1827 women with AF were identified. AF prevalence increased every year as women aged from 2.71% (95% CI 1.62%-3.80%) in 2000 among women aged 74-79 years to 24.83% (95% CI = 23.23%-26.44%) in 2015 among women aged 89-94 years. The incidence proportion remained constant (between 3% and 5%) throughout the study period. Sedentary lifestyle (OR = 1.24, 95% CI = 1.04-1.49), hypertension (OR = 1.24, 95% CI = 1.09-1.42), arthritis (OR = 1.24, 95% CI = 1.09-1.41), heart attack (OR = 1.62, 95% CI = 1.18-2.24), and angina (OR = 1.39, 95% CI = 1.14-1.70) were independently associated with AF. Mean CHA2DS2-VA score for women with AF was 3.43 (SD ± 1.23).

CONCLUSIONS

The prevalence of AF reported in Australian women is among the highest compared to previous estimations from other countries and regions. According to the findings, about one in four women over the age of 90 years had AF. These women were also at high risk of stroke. This has significant public health implications especially with changing demographics of increase in the aging population. Further research is required on understanding how women with AF are treated in Australia and their health outcomes.

Cost-effectiveness of targeted screening for the identification of patients with atrial fibrillation: evaluation of a machine learning risk prediction algorithm

Aims: As many cases of atrial fibrillation (AF) are asymptomatic, patients often remain undiagnosed until complications (e.g. stroke) manifest. Risk-prediction algorithms may help to efficiently identify people with undiagnosed AF. However, the cost-effectiveness of targeted screening remains uncertain. This study aimed to assess the cost-effectiveness of targeted screening, informed by a machine learning (ML) risk prediction algorithm, to identify patients with AF.Methods: Cost-effectiveness analyses were undertaken utilizing a hybrid screening decision tree and Markov disease progression model. Costs and outcomes associated with the detection of AF compared traditional systematic and opportunistic AF screening strategies to targeted screening informed by a ML risk prediction algorithm. Model analyses were based on adults ≥50 years and adopted the UK NHS perspective.Results: Targeted screening using the ML risk prediction algorithm required fewer patients to be screened (61 per 1,000 patients, compared to 534 and 687 patients in the systematic and opportunistic strategies) and detected more AF cases (11 per 1,000 patients, compared to 6 and 8 AF cases in the systematic and opportunistic screening strategies). The targeted approach demonstrated cost-effectiveness under base case settings (cost per QALY gained of £4,847 and £5,544 against systematic and opportunistic screening respectively). The targeted screening strategy was predicted to provide an additional 3.40 and 2.05 QALYs per 1,000 patients screened versus systematic and opportunistic strategies. The targeted screening strategy remained cost-effective in all scenarios evaluated.Limitations: The analysis relied on assumptions that include the extended period of patient life span and the lack of consideration for treatment discontinuations/switching, as well as the assumption that the ML risk-prediction algorithm will identify asymptomatic AF.Conclusions: Targeted screening using a ML risk prediction algorithm has the potential to enhance the clinical and cost-effectiveness of AF screening, improving health outcomes through efficient use of limited healthcare resources.

[Cardiac magnetic resonance imaging with contrast enhancement in treatment of atrial fibrillation]

Catheter ablation is presently the main method for interventional treatment of atrial fibrillation (AF). Despite improvements of the method and accumulation of personnel's experience, incidence of recurrent AF following catheter interventions remains high. This review addresses a possibility of using contrast-enhanced cardiac magnetic resonance imaging to increase the effectiveness of interventional treatment of arrhythmia.

PREvention of recurrent arrhythmias with Mediterranean diet (PREDIMAR) study in patients with atrial fibrillation: Rationale, design and methods

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Catheter ablation aims to restore sinus rhythm. However, relapses occur in up to 30% of patients. A Mediterranean diet (MedDiet) enriched with extra-virgin olive oil (EVOO) substantially reduced the incidence of AF in the PREDIMED trial. The PREDIMAR will test a similar intervention in secondary prevention.

Methods

PREDIMAR is a multicenter, randomized, single-blind trial testing the effect of a MedDiet enriched with EVOO to reduce tachyarrhythmia relapses after AF ablation. The primary outcome is the recurrence of any sustained atrial tachyarrhythmia after ablation (excluding those occurring only during the first 3 months after ablation). The target final sample size is 720 patients (360 per group) recruited from 4 Spanish hospitals. A remote intervention, maintained for 2 years, is delivered to the active intervention group including periodic phone calls by a dietitian and free provision of EVOO. The control group will receive delayed intervention after trial completion. Routine electrocardiogram (ECG) and Holter ECG are performed, and a portable cardiac rhythm monitoring device is provided to be worn by participants during 15 months.

Results

Recruitment started in March 2017. Up to July 2019, 609 patients were randomized (average inclusion rate: 5.3 patients/wk). Retention rates after 18 months are >94%.

Conclusions

If our hypothesis is confirmed, the utility of the MedDiet enriched with EVOO in slowing the progression of AF will be proven, preventing recurrences and potentially reducing complications.

Quality of Warfarin Anticoagulation in Indigenous and Non-Indigenous Australians With Atrial Fibrillation

BACKGROUND

Studies have shown that suboptimal anticoagulation quality, as measured by time in therapeutic range (TTR), affects a significant percentage of patients with atrial fibrillation (AF). However, TTR has not been previously characterised in Indigenous Australians who experience a greater burden of AF and stroke.

METHOD

Indigenous and non-Indigenous Australians with AF on warfarin anticoagulation therapy were identified from a large tertiary referral centre between 1999 and 2012. Time in therapeutic range was calculated as a proportion of daily international normalised ratio (INR) values between 2 and 3 for non-valvular AF and 2.5 to 3.5 for valvular AF. INR values between tests were imputed using the Rosendaal technique. Linear regression models were employed to characterise predictors of TTR.

RESULTS

Five hundred and twelve (512) patients with AF on warfarin were included (88 Indigenous and 424 non-Indigenous). Despite younger age (51±13 vs 71±12 years, p<0.001), Indigenous Australians had greater valvular heart disease, diabetes, and alcohol excess compared to non-Indigenous Australians (p<0.05 for all). Time in therapeutic range was significantly lower in Indigenous compared to non-Indigenous Australians (40±29 vs 50±31%, p=0.006). Univariate predictors of poorer TTR included Indigenous ethnicity, younger age, diuretic use, and comorbidities, such as valvular heart disease, heart failure and chronic obstructive pulmonary disease (p<0.05 for all). Valvular heart disease remained a significant predictor of poorer TTR in multivariate analyses (p=0.004).

CONCLUSION

Indigenous Australians experience particularly poor warfarin anticoagulation quality. Our data also suggest that many non-Indigenous Australians spend suboptimal time in therapeutic range. These findings reinforce the importance of monitoring warfarin anticoagulation quality to minimise stroke risk.

Management of patients with newly-diagnosed atrial fibrillation: Insights from the BALKAN-AF survey

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23.6% of patients in the survey had newly-diagnosed atrial fibrillation (AF).

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Those patients had different risk profiles than those with a history of AF.

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The specificity of the management of first-diagnosed AF patients was presented.

Background

BALKAN-AF evaluated patterns of atrial fibrillation (AF) management in real-world clinical practice in the Balkans. The objectives were: to assess the proportion of patients with first-diagnosed AF in the BALKAN-AF cohort and to compare the management of patients with newly-diagnosed AF and those with previously known AF in clinical practice.

Methods

Consecutive patients from 7 Balkan countries were enrolled prospectively to the snapshot BALKAN-AF survey.

Results

Of 2712 enrolled patients, 2677 (98.7%) with complete data were included. 631 (23.6%) patients had newly-diagnosed AF and 2046 (76.4%) patients had known AF. Patients with newly-diagnosed AF were more likely to be hospitalized for AF and to receive single antiplatelet therapy (SAPT) alone and less likely to receive OACs than those with known AF (all p < 0.001). The use of OAC was not significantly associated with the CHA₂DS₂-VASc (p = 0.624) or HAS-BLED score (p = 0.225) on univariate analysis. Treatment in capital city, hypertension, dilated cardiomyopathy, mitral valve disease, country of residence or rate control strategy were independent predictors of OAC use, whilst non-emergency centre, treatment by cardiologist, paroxysmal AF, palpitations, symptoms attributable to AF (as judged by physician), mean heart rate and AF as the main reason for hospitalization were independent predictors of rhythm control strategy use.

Conclusions

In BALKAN-AF survey, patients with newly-diagnosed AF were more often hospitalized, less often received OAC and were more likely to receive SAPT alone. The use of OAC for stroke prevention has not been driven by the individual patient stroke risk.

Hypertension and Arrhythmias

Hypertension is the most common cardiovascular risk factor and underlies heart failure, coronary artery disease, stroke, and chronic kidney disease. Hypertensive heart disease can manifest as cardiac arrhythmias. Supraventricular and ventricular arrhythmias may occur in the hypertensive patients. Atrial fibrillation and hypertension contribute to an increased risk of stroke. Some antihypertensive drugs predispose to electrolyte abnormalities, which may result in atrial and ventricular arrhythmias. A multipronged strategy involving appropriate screening, aggressive lifestyle modifications, and optimal pharmacotherapy can result in improved blood pressure control and prevent the onset or delay progression of heart failure, coronary artery disease, and cardiac arrhythmias.

Plasma Level of Interferon-γ Predicts the Prognosis in Patients With New-Onset Atrial Fibrillation

BACKGROUND

Patients with atrial fibrillation are at increased risk of stroke and mortality. It is not clear if inflammatory biomarkers are associated with stroke and mortality in patients with atrial fibrillation. We aimed to evaluate the predictive value of three inflammatory biomarkers (interleukin [IL]-9, IL-10, and interferon [IFN]-γ) for stroke and mortality in atrial fibrillation.

METHOD

A total of 232 patients with new-onset atrial fibrillation were enrolled and 217 patients were completely followed-up. Peripheral plasma concentrations of cytokines (IL-9, IL-10, and IFN-γ) were measured using Luminex xMAP assays. The association between dichotomous groups of cytokines and outcomes were evaluated by a Cox proportional hazards model. The incremental value of inflammatory biomarkers, in addition to the CHA₂DS₂-VASc score, was also assessed.

RESULTS

Patients were followed-up for a median duration of 27 (interquartile range [IQR], 23-30) months. The elevated plasma level of IFN-γ was an independent risk factor for stroke (hazard ratio [HR], 4.02 [IQR, 1.06-15.34]; p=0.042) and all-cause mortality (HR, 3.93 [IQR, 1.43-10.78]; p=0.008) in patients with atrial fibrillation. Adding high IFN-γ to the CHA₂DS₂-VASc score showed improvement in discrimination and reclassification prediction for stroke and mortality. However, IL-9 and IL-10 had no statistically significant association with stroke and all-cause mortality in patients with atrial fibrillation.

CONCLUSIONS

In this "real-world" cohort of patients with atrial fibrillation, we have shown for the first time that plasma levels of IFN-γ could provide incremental prognostic value supplementary to that obtained from the CHA₂DS₂-VASc scores for predicting of stroke and all-cause mortality.

Atrial fibrillation: an update on management

Atrial fibrillation carries a markedly increased risk of stroke and left ventricular dysfunction, and is associated with reduced quality of life In light of the potential for poor outcomes and the likely understated presence of silent atrial fibrillation, opportunistic screening should be carried out in general practice Modifying the risk factors for atrial fibrillation is the cornerstone of management with adjuvant drug therapy to help maintain sinus rhythm, control the ventricular rate and reduce the risk of cerebral thromboembolism The need for anticoagulant therapy can be assessed by using the revised CHA2DS2-VASc score. Direct oral anticoagulants are now preferred to warfarin in those who qualify for their use Catheter ablation is an effective option to improve survival in patients with left ventricular dysfunction. It also improves quality of life and reduces arrhythmia-related hospital admissions

Mechanisms of atrial fibrillation

Atrial fibrillation (AF) is the most common sustained arrhythmia, currently affecting over 33 million individuals worldwide, and its prevalence is expected to more than double over the next 40 years. AF is associated with a twofold increase in premature mortality, and important major adverse cardiovascular events such as heart failure, severe stroke and myocardial infarction. Significant effort has been made over a number of years to define the underlying cellular, molecular and electrophysiological changes that predispose to the induction and maintenance of AF in patients. Progress has been limited by the realisation that AF is a complex arrhythmia that can be the end result of various different pathophysiological processes, with significant heterogeneity between individual patients (and between species). In this focused Review article, we aim to succinctly summarise for the non-specialist the current state of knowledge regarding the mechanisms of AF. We address all aspects of pathophysiology, including the basic electrophysiological and structural changes within the left atrium, the genetics of AF and the links to comorbidities and wider systemic and metabolic perturbations that may be upstream contributors to development of AF. Finally, we outline the translational implications for current and future rhythm control strategies in patients with AF.

Smartwatch for the Detection of Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia and poses a substantial economic burden due to associated thromboembolic complications. Screening for AF may theoretically be effective, but there is no consensus regarding the optimal screening method because the available tools are either invasive or not cost-effective. Recently, smartwatch industry has received a surge of interest for this purpose by introducing technologies such as photoplethysmography, artificial intelligence, and actual electrodes taking an electrocardiogram to measure and analyze heart rate and rhythm with relatively acceptable accuracy. Combined with other features such as ease of use and connectivity, smartwatches can potentially be used for large-scale AF screening and might eventually replace the current gold standards. In this review, we discuss the feasibility of this approach and summarize the current evidence on AF detection with smartwatches.

Concomitant pulmonary vein isolation and percutaneous closure of atrial septal defects: A pilot project

Background

Patients with an atrial septal defect (ASD) are at increased risk of developing atrial fibrillation (AF). Currently percutaneous ASD closure is the preferred therapeutic strategy and although pulmonary vein isolation (PVI) for AF is feasible after ASD closure, the transseptal puncture can be technically challenging and probably increases the perioperative risk. A staged approach, with PVI several months before ASD closure, has been recommended for patients already scheduled for closure, but no data are available on combined procedures.

Purpose

This pilot study evaluates the feasibility of a combined procedure of PVI and ASD closure in patients with a hemodynamic important ASD and documented AF.

Methods

In one procedure, PVI was performed prior to placement of the ASD closure device. Transseptal access for PVI was obtained via wire passage through the ASD in all patients. Patients were followed with 5‐day‐holter monitoring at 3, 6, and 12 months. Recurrence of AF was defined as a documented, symptomatic episode of AF.

Results

The study population consisted of five patients (four females, mean age: 58 (±3) years). Acute PVI was achieved in all patients. Only one patient had a small residual ASD after closure. Besides a small groin hematoma in two patients, no complications occurred. After 12‐month follow‐up, three patients were free of AF recurrence (60%).

Conclusion

This study shows that a combined PVI with ASD closure is feasible with an acceptable success rate of AF free survival. These preliminary results in a small patient group warrants a larger trial.

Mechanism of electrical remodeling of atrial myocytes and its influence on susceptibility to atrial fibrillation in diabetic rats

AIMS

To explore the atrial electrical remodeling and the susceptibility of atrial fibrillation (AF) in diabetic rats.

MATERIALS AND METHODS

Zucker diabetic fatty (ZDF) rats were chosen as diabetic animal model, and age-matched non-diabetic littermate Zucker lean (ZL) rats as control. AF susceptibility was determined by electrophysiological examination. The current density of I_to, I_Kur and I_Ca-L were detected by whole-cell patch-clamp technique, and ion channel protein expression in atrial tissue and HL-1 cells treated with advanced glycation end products (AGE) was analyzed by western blotting.

KEY FINDINGS

Diabetic rats had significantly enlarged left atria and evenly thickened ventricular walls, hypertrophied cells and interstitial fibrosis in atrial myocardium, increased AF susceptibility, and prolonged AF duration after atrial burst stimulation. Compared with atrial myocytes isolated from ZL controls, atrial myocytes isolated from ZDF rats had prolonged action potential duration, decreased absolute value of resting membrane potential level and current densities of I_to, I_Kur and I_Ca-L. The ion channel protein (Kv4.3, Kv1.5 and Cav1.2) expression in atrium tissue of ZDF rats and HL-1 cells treated with high concentration AGE were significantly down-regulated, compared with controls.

SIGNIFICANCE

The atrial electrical remodeling induced by hyperglycemia contributed to the increased AF susceptibility in diabetic rats.

A systematic review protocol for examining 30-day readmission costs for atrial fibrillation patients

INTRODUCTION

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and readmissions of AF patients place a huge burden on the healthcare system, including economically. With an increasing prevalence, the burden of AF will continue evolving. To illuminate the readmission-specific economic burden, we aim to provide quality evidence on the cost of readmissions within 30 days where AF has been the primary diagnosis at the index admission.

METHODS AND ANALYSIS

We will conduct a systematic review of all peer-reviewed articles examining readmission costs for AF patients. We will search MedLine, Cumulative Index to Nursing and Allied Health Literature, Scopus and Cochrane Library for articles written in English, published in peer-reviewed journals from inception to 2019. Reporting of this protocol follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols checklist. Studies will be included if patients were aged 18 years and over, AF was the primary diagnosis of index admission and costs of readmission within 30 days were reported. Quality assessment of studies will be done using a modified Evers checklist. Study results will be summarised in a Forest plot and heterogeneity tested for using the Cochran's Q and I² statistic. A random-effects model will be applied for meta-analysis if studies are sufficiently homogeneous. The cost of readmission to hospital within 30 days for AF patients is the main outcome of interest while additional outcomes are 30-day readmission rate, predictors of readmission and predictors of readmission costs.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as no patients will be involved. Dissemination of results will be through a peer-reviewed publication.

PROSPERO REGISTRATION NUMBER

CRD42019132017.

Prevalence and Characteristics of Subclinical Atrial Fibrillation in a Community-Dwelling Elderly Population: The ARIC Study

BACKGROUND

The prevalence of subclinical atrial fibrillation (AF) in the elderly general population is unclear. We sought to define the prevalence of subclinical AF in a community-based elderly population and to characterize subclinical AF and the incremental diagnostic yield of 4 versus 2 weeks of continuous ECG monitoring.

METHODS

We conducted a cross-sectional analysis within the community-based multicenter observational ARIC study (Atherosclerosis Risk in Communities) using visit 6 (2016-2017) data. The 2616 ARIC study participants who wore a leadless, ambulatory ECG monitor (Zio XT Patch) for up to 2 weeks were aged 79±5 years, 42% men, and 26% black. In a subset, 386 participants without clinically recognized AF wore the monitor twice, each time for up to 2 weeks. We characterized the prevalence of subclinical AF (ie, AF detected on the Zio XT Patch without clinically recognized AF) over 2 weeks of monitoring and the diagnostic yield of 4 versus 2 weeks of monitoring.

RESULTS

The prevalence of subclinical AF was 2.5%; the prevalence of subclinical AF was 3.3% among white men, 2.5% among white women, 2.1% among black men, and 1.6% among black women. Subclinical AF was mostly intermittent (75%). Among those with intermittent subclinical AF, 91% had AF burden ≤10% during the monitoring period. In a subset of 386 participants without clinical AF, 78% more subclinical AF was detected by 4 weeks versus 2 weeks of ECG monitoring.

CONCLUSIONS

In our study, the prevalence of subclinical AF was lower than previously reported and monitoring beyond 2 weeks provided substantial incremental diagnostic yield. Future studies should focus on individuals with higher risk to increase diagnostic yield and consider continuous monitoring duration longer than 2 weeks.

Comparison of In-Hospital Outcomes of Patients With-Versus-Without Atrial Fibrillation and Alcohol Withdrawal Syndrome

Alcohol withdrawal syndrome (AWS) has been associated with significant medical complications and length of stay. Cardiovascular effects from AWS include a physiologic tachycardia and hypertensive response. Although atrial fibrillation (AF) is one of the most common arrhythmias, the impact of a known history of AF on AWS is unclear. The purpose of our study is to assess the impact of history of AF on clinical outcomes, cost, and length of stay on AWS. The Nationwide Inpatient Sample was used to identify patients aged 18 years or older who underwent AWS with or without AF using the International Classification of Disease 9 Clinical Modification codes from January 2010 to December 2014. Outcomes were compared between those with or without AF using propensity score method-stratified morbidity ratio weighing- to adjust for baseline patient and hospital characteristics. A total of 280,451 patients with AWS of which 14,459 (5.2%) had history of AF. Patients with AF was older, less likely female, and more had higher burden of co-morbidities. In an adjusted model, in-hospital mortality (odds ratio [OR] 1.98 95% confidence interval [CI] 1.61 to 2.45), ischemic stroke (OR 1.67 95% CI 1.42 to 1.95), acute kidney injury (OR 1.36 95% CI 1.24 to 1.49), acute kidney injury requiring dialysis (OR 1.89 95% CI 1.39 to 2.50), and cost (mean ratio 1.27 95% CI 1.21 to 1.33) were higher in the AF cohort. Length of stay was shorter in patients with AF (mean ratio 0.85 95% CI 0.81 to 0.90). In conclusion, a known history of AF increased the risk of in-hospital mortality, morbidity, and hospital expense in AWS.

Application of Ultrasound Thermal Imaging for Monitoring Laser Ablation in Ex Vivo Cardiac Tissue

BACKGROUND AND OBJECTIVE

Laser ablation can be used to treat atrial fibrillation by thermally isolating pulmonary veins. In this study, we evaluated the feasibility of high-resolution (<1 mm) ultrasound thermal imaging to monitor spatial temperature distribution during laser ablation on ex vivo cardiac tissue.

STUDY DESIGN/MATERIALS AND METHODS

Laser ablation (808 nm) was performed on five porcine cardiac tissue samples. A thermocouple was used to measure the interstitial tissue temperature during the laser ablation process. Tissue-strain-based ultrasound thermal imaging was conducted to monitor the spatial distribution of the temperature in the cardiac tissue. The tissue temperature was estimated from the time shifts of ultrasound signals owing to the changes in the speed of sound and was compared with the measured temperature. The temperature estimation coefficient k of porcine cardiac tissue was calculated from the estimated thermal strain and the measured temperature. The degree of tissue coagulation (temperatures > 50°C) was derived from the estimated temperature and was compared with that of the tested cardiac tissue.

RESULTS

The estimated tissue temperature using strain-based ultrasound thermal imaging at a depth of 1 mm agreed with thermocouple measurements. During the 30-second period of the laser ablation process, the estimated tissue temperature increased from 25 to 70°C at a depth of 0.1 mm, while the estimated temperature at a depth of 1 mm increased up to 46°C. Owing to the uncertainty of the coefficient k, the k value of the porcine cardiac tissue varied from 160 to 220°C with temperature changes of up to 20°C. The estimated coagulation region in the ultrasound thermal imaging was 20% wider (+0.6 mm) but 9% shallower (-0.1 mm) than the measured region of the ablated porcine cardiac tissue.

CONCLUSIONS

The current study demonstrated the feasibility of temperature monitoring with the use of ultrasound thermal imaging during the laser ablation on ex vivo porcine cardiac tissue. The high-resolution ultrasound thermal imaging could map the spatial distribution of the tissue temperature. The proposed method can be used to monitor the temperature and thermal coagulation to achieve effective laser ablation for atrial fibrillation. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Within trial cost-utility analysis of disease management program for patients hospitalized with atrial fibrillation: results from the SAFETY trial

Background: The potential impact of disease management to optimize quality of care, health outcomes, and total healthcare costs across a range of cardiac disease states is unknown. Methods: A trial-based cost-utility analysis was conducted alongside a randomized controlled trial of 335 patients with chronic, non-valvular AF (without heart failure; the SAFETY Trial) discharged to home from three tertiary referral hospitals in Australia. A home-based disease management intervention (the SAFETY intervention) that involved community-based AF care including home visits was compared to routine primary healthcare and hospital outpatient follow-up (standard management). Bootstrapped incremental cost-utility ratios were computed based on quality-adjusted life-years (QALYs) and total healthcare costs. Cost-effectiveness acceptability curves were constructed to explore the probability of the SAFETY intervention being cost-effective. Sub-group analyses were performed based on age and sex to determine differential cost-effectiveness. Results: During median follow-up of 1.75 years, the SAFETY intervention was associated with a non-statistically significant increase in QALYs (0.02 per person) and lower total healthcare costs (-$4,375 per person). Although each of these findings were not statistically significant, the SAFETY intervention was found to be dominant (more effective and cost saving) in 58.8% of the bootstrapped iterations and cost-effective (more effective and gains in QALYs achieved at or below $50,000 per QALY gained) in 61.5% of the iterations. Males and those aged less than 78 years achieved greater gains in QALYs and savings in healthcare costs. The estimated value of perfect information in Australia (the monetized value of removing uncertainty in the cost-effectiveness results) was A$51 million, thus demonstrating the high potential gain from further research. Conclusions: Compared with standard management, the SAFETY intervention is potentially a dominant strategy for those with chronic, non-valvular AF. However, there would be substantial value in reducing the uncertainty in these estimates from further research.

Prevalence of atrial fibrillation and stroke risk assessment based on telemedicine screening tools in a primary healthcare setting

BACKGROUND

Worldwide atrial fibrillation (AF) prevalence varies between 0.1% and 4.0%, and has been increasing. Little is known about the prevalence of AF in Brazil. Our objective was to estimate the prevalence of AF in several regions of Brazil using recordings of long-distance electrocardiogram (ECG) transmission.

METHODS

Patients from 125 outpatient general practitioner units covered by the telemedicine service of the Federal University of São Paulo were included. Only one ECG was considered per patient. A scripted telephone interview was also performed. We analyzed the data to project the prevalence of AF in the Brazilian population and estimate it for the year 2025. The overall AF prevalence was calculated based on ECGs from primary care units where patients went for routine visits.

RESULTS

Based on 676,621 ECG exams from January 2009 through April 2016, the mean age (±SD) of patients was 51.38 (±19.05) years, with 57.5% being female. The 7-year period prevalence of AF was 2.2% (n = 14,968). The prevalence of AF countrywide was projected to be 1.5% in 2016 and 1.7% in 2025. In the subset of patients with AF who were interviewed (n = 301), 91 (30.2%) were not receiving any type of treatment for rate or rhythm control. Among patients interviewed, 189 (62.8%) were at high risk for stroke; only 28 (14.8%) were regular oral anticoagulant users.

CONCLUSIONS

Our study highlights the importance of screening for AF in the primary care setting in Brazil and identifies important gaps in the treatment of AF in this population.

Factors That Affect Time to Switch From Warfarin to a Direct Oral Anticoagulant After Change in the Reimbursement Criteria in Patients With Atrial Fibrillation

BACKGROUND

Anticoagulation therapy is recommended for stroke prevention in high-risk patients with atrial fibrillation (AF). This study aimed to estimate the time to switch from warfarin to a direct oral anticoagulant (DOAC) and identify the factors associated with it.

METHODS

By using claims data, we studied 7111 warfarin-using patients with nonvalvular AF who were aged ≥65 years. The Kaplan-Meier analysis was performed to estimate the time to switch from warfarin to a DOAC, and Cox proportional hazard regression analysis was used to estimate the influencing factors.

RESULTS

Approximately one-third of the patients (2403, 33.8%) switched from warfarin to a DOAC during the study period. Female sex, aged between 75 and 79 years, having a Medical Aid or Patriots and Veterans Insurance, hypertension, and history of prior stroke, and transient ischemic attack or thromboembolism (prior stroke/TIA/TE) were associated with a significantly shorter time to switch. The odds of switching to a DOAC were increased by approximately 1.2-fold in the women and 1.4-fold in the patients with prior stroke/TIA/TE.

CONCLUSIONS

Approximately one-third of the warfarin-using patients switched from warfarin to a DOAC within 6 months after the change in the DOAC reimbursement criteria. In the Cox proportional hazard regression analysis, the factors that affected anticoagulant switching from warfarin to a DOAC were female sex and history of prior stroke/TIA/TE.

Healthcare costs of stroke and major bleeding in patients with atrial fibrillation treated with non-vitamin K antagonist oral anticoagulants

Objective: To assess long-term healthcare costs related to ischemic stroke and systemic embolism (stroke/SE) and major bleeding (MB) events in patients with non-valvular atrial fibrillation (NVAF) treated with non-vitamin K antagonist oral anticoagulants (NOACs). Materials and methods: Optum's Clinformatics Data Mart database from 1/2009-12/2016 was analyzed. Adult patients with ≥1 stroke/SE hospitalization (index date) were matched 1:1 to patients without stroke/SE (random index date), based on propensity scores. Patients with an MB event were matched to patients without MB. All patients had an NOAC dispensing overlapping index date, ≥12 months of eligibility pre-index date, and ≥1 NVAF diagnosis. The observation period spanned from the index date until the earliest date of death, switch to warfarin, end of insurance coverage, or end of data availability. Mean costs were evaluated: (1) per-patient-per-year (PPPY) and (2) at 1, 2, 3, and 4 years using Lin's method. Results: The cost differences were, respectively, $48,807 and $28,298 PPPY for NOAC users with stroke/SE (n = 1,340) and those with MB (n = 3,774) events compared to controls. Cost differences of patients with vs without stroke/SE were $49,876, $51,627, $57,822, and $60,691 at 1, 2, 3, and 4 years post-index, respectively (p < 0.001). These cost differences were $31,292, $35,658, $44,069, and $47,022 for patients with vs without MB after 1, 2, 3, and 4 years post-index, respectively (p < 0.001). Limitations: Limitations include unobserved confounders, coding and/or billing inaccuracies, limited sample sizes over longer follow-up, and the under-reporting of mortality for deaths occurring after 2011. Conclusions: The incremental healthcare costs incurred by patients with vs without stroke/SE was nearly twice as high as those of patients with vs without MB. Moreover, each additional year up to 4 years after the first event was associated with an incremental cost for patients with a stroke/SE or MB event compared to those without an event.

GWAS contribution to atrial fibrillation and atrial fibrillation-related stroke: pathophysiological implications

Atrial fibrillation (AF) and stroke are included in a group of complex traits that have been approached regarding of their study by susceptibility genetic determinants. Since 2007, several genome-wide association studies (GWAS) aiming to identify genetic variants modulating AF risk have been conducted. Thus, 11 GWAS have identified 26 SNPs (p < 5 × 10^-2), of which 19 reached genome-wide significance (p < 5 × 10^-8). From those variants, seven were also associated with cardioembolic stroke and three reached genome-wide significance in stroke GWAS. These associations may shed a light on putative shared etiologic mechanisms between AF and cardioembolic stroke. Additionally, some of these identified variants have been incorporated in genetic risk scores in order to elucidate new approaches of stroke prediction, prevention and treatment.

Healthcare Utilization and Costs Reduction after Radiofrequency Ablation For Atrial Fibrillation in the Brazilian Private Healthcare System

Background

Atrial fibrillation (AF) is the most common arrhythmia worldwide, with significantly associated hospitalizations. Considering its growing incidence, the AF related economic burden to healthcare systems is increasing. Healthcare expenditures might be substantially reduced after AF radiofrequency ablation (AFRA).

Objective

To compare resource utilization and costs before and after AFRA in a cohort of patients from the Brazilian private healthcare system.

Methods

We conducted a retrospective cohort study, based on patients’ billing information from an administrative database. Eighty-three adult patients who had an AFRA procedure between 2014 and 2015 were included. Healthcare resource utilization related to cardiovascular causes, including ambulatory and hospital care, as well as its costs, were analyzed. A p-value of less than 0.05 was considered statistically significant.

Results

Mean follow-up was 14.7 ± 7.1 and 10.7 ± 5.4 months before and after AFRA, respectively. The 1-year AF recurrence-free rate was 83.6%. Before AFRA, median monthly total costs were Brazilian Reais (BRL) 286 (interquartile range [IQR]: 137-766), which decreased by 63.5% (p = 0.001) after the procedure, to BRL 104 (IQR: 57-232). Costs were reduced both in the emergency (by 58.6%, p < 0.001) and outpatient settings (by 56%, p < 0.001); there were no significant differences in the outpatient visits, inpatient elective admissions and elective admission costs before and after AFRA. The monthly median emergency department visits were reduced (p < 0.001).

Conclusion

In this cohort, overall healthcare costs were reduced by 63.5%. A longer follow-up could be useful to evaluate if long-term cost reduction is maintained.

2018 Focused Update of the Canadian Cardiovascular Society Guidelines for the Management of Atrial Fibrillation

The Canadian Cardiovascular Society (CCS) Atrial Fibrillation Guidelines Committee provides periodic reviews of new data to produce focused updates that address clinically important advances in atrial fibrillation (AF) management. This 2018 Focused Update addresses: (1) anticoagulation in the context of cardioversion of AF; (2) the management of antithrombotic therapy for patients with AF in the context of coronary artery disease; (3) investigation and management of subclinical AF; (4) the use of antidotes for the reversal of non-vitamin K antagonist oral anticoagulants; (5) acute pharmacological cardioversion of AF; (6) catheter ablation for AF, including patients with concomitant AF and heart failure; and (7) an integrated approach to the patient with AF and modifiable cardiovascular risk factors. The recommendations were developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) standards. Individual studies and literature were reviewed for quality and bias; the literature review process and evidence tables are included as Supplementary Material and are available on the CCS Web site. Details of the updated recommendations are presented, along with their background and rationale. This document is linked to an updated summary of all CCS AF guidelines recommendations, from 2010 to the present 2018 Focused Update, which is provided in the Supplementary Material.

Awareness of atrial fibrillation-effectiveness of a pilot national awareness campaign

BACKGROUND

Although atrial fibrillation (AF) causes one-third of strokes in Ireland, studies have shown that public awareness and knowledge of AF are poor. The Irish Heart Foundation conducted a national AF awareness campaign in 2013.

AIMS

The aim of this study was to assess the effectiveness of the campaign in promoting awareness of AF in the general Irish population, by analyzing knowledge of AF at a population level pre- and post-campaign.

METHODS

Two thousand people were surveyed before the campaign to establish baseline knowledge, and the survey was then repeated in a sample of 1000 people in 2 months after the end of the campaign.

RESULTS

Awareness of AF was low, with 28% (560/2000) of those surveyed reporting they had heard of AF prior to the campaign and 30% (297/1002) after (p 0.347). Of those that had heard of the condition, 58% (174/300) in the pre-campaign group correctly identified AF as an irregular heartbeat compared with 35% (105/297) of the post-campaign group (p < 0.01).

CONCLUSIONS

Our study shows that overall public knowledge of AF in Ireland is generally poor. While this pilot national awareness campaign had no positive impact on awareness levels, there are several possible reasons for this including the limited funding allocation to the campaign. A further AF awareness campaign is planned for next year.

[Factors associated with atrial fibrillation in patients with hypertension and preserved left ventricle systolic function]

The objective of our study was to define factors associated with atrial fibrillation (AF) in patients with hypertension (HTN) and preserved left ventricle systolic function.

MATERIAL AND METHODS

Overall, 273 consecutive patients with HTN residing in urban area were included in the study. Patients were divided into 2 groups: the first - 60 patients with paroxysmal and persistent AF (33% men, age 62, 28 (10,02), the second - 213 patients without AF (33% men, age 59,37 (8,27).

RESULTS

Stepwise logistic regression analysis demonstrated AF presence was associated with alcohol intake ≥ 7 drinks per week (OR 4,12; 95%CI: 1,04-16,35), low physical activity (OR 3,18; 95% CI: 1,32-7,68), higher hip circumference (OR 1,19; 95% CI: 1,08-1,31) and history of HTN (OR 1,10; 95% CI: 1,04-1,17). BMI was not associated with presence of AF (OR 0,75; 95% CI: 0,61-0,91).

CONCLUSION

Thus in our urban population with hypertension, AF is associated with alcohol intake ≥ 7 drinks per week, low physical activity, increased hip circumference and history of hypertension.AF prevention should include modification of lifestyle.

An Update on the Development and Feasibility Assessment of Canadian Quality Indicators for Atrial Fibrillation and Atrial Flutter

Background

In 2010, the Canadian Cardiovascular Society Atrial Fibrillation/Atrial Flutter (AF/AFL) quality indicator (QI) working group was established to develop QIs and assess feasibility of measurement. After extensive review, 3 priority QIs were selected. However, none were measurable at a national level.

Methods

The working group reconvened in 2017 to review the relevance of previously proposed QIs, identify opportunities to develop new QIs, and propose an initial strategy for measuring and reporting.

Results

Two additional priority QIs were added to the previous 3: proportion of patients with nonvalvular (NV) AF/AFL sorted by stroke risk stratum and annual rate of hospitalization for a new heart failure diagnosis. An environmental scan was undertaken to determine the potential of existing databases to provide national and provincial estimates. On the basis of validated administrative codes, the Canadian Institute for Health Information discharge abstract database can be used for inpatients. In collaboration with the Canadian Primary Care Sentinel Surveillance Network, 2 of the 5 QIs can be assessed in outpatients (patients with NVAF/AFL sorted by stroke risk stratum and high risk for stroke NVAF/AFL receiving oral anticoagulation). Stroke prevention therapy can be further measured in selected provinces with linked databases including prescriptions.

Conclusions

This first step could provide a better initial understanding of the quality of AF/AFL care in Canada, but important gaps in the meaningful measurement of QIs remain. The AF/AFL QI working group has limited capacity to make progress without national level leadership and the resources to support data aggregation, data analysis, and pan-Canadian reporting.

Olive oil intake and risk of atrial fibrillation in the SUN cohort

BACKGROUND AND AIMS

A Mediterranean-type diet enriched with extra virgin olive oil has been associated with a reduction in the incidence of atrial fibrillation (AF) in a population at high cardiovascular risk. However, no study has replicated these findings. In our study, we analyzed the association between olive oil consumption and AF in the SUN project, a cohort with young Spanish adults at low cardiovascular risk.

METHODS AND RESULTS

We included all participants without prevalent AF at baseline (18,118 participants). Incident AF cases were confirmed by a cardiologist following a prespecified protocol. We used multivariable repeated-measurement Cox models adjusted for possible confounders (sex, age, BMI, and several classic cardiovascular risk factors). After a mean follow-up of 10.1 years, 94 AF incident cases were confirmed. Comparing to the lowest category of consumption (<7.9 g/d), the multivariable models showed hazard ratios (IC 95%) of 1.52 (0.93-2.48) for low-to-moderate, 1.44 (0.83-2.47) for moderate-to-high and 1.27 (0.56-2.86) for high olive oil intake. In a subgroup analysis stratified by overweight, an inverse although non-significant association was found only among overweight participants when we compared the highest vs the lowest category of consumption (p for interaction = 0.043).

CONCLUSION

No association between olive oil and AF was found in this low-risk cohort, although the effect of extra-virgin olive oil on AF prevention especially among people with overweight deserves further investigation.

Body composition and atrial fibrillation: a Mendelian randomization study

AIMS

Increases in fat-free mass and fat mass have been associated with higher risk of atrial fibrillation (AF) in observational studies. It is not known whether these associations reflect independent causal processes. Our aim was to evaluate independent causal roles of fat-free mass and fat mass on AF.

METHODS AND RESULTS

We conducted a large observational study to estimate the associations between fat-free mass and fat mass on incident AF in the UK Biobank (N = 487 404, N events = 10 365). Genome-wide association analysis was performed to obtain genetic instruments for Mendelian randomization (MR). We evaluated the causal effects of fat-free mass and fat mass on AF with two-sample method by using genetic associations from AFGen consortium as outcome. Finally, we evaluated independent causal effects of fat-free mass and fat mass with multivariate MR. Both fat-free mass and fat mass had observational associations with incident AF [hazard ratio (HR) = 1.77, 95% confidence interval (CI) 1.72-1.83; HR = 1.40, 95% CI 1.37-1.43 per standard deviation increase in fat-free and fat mass, respectively]. The causal effects using the inverse-variance weighted method were 1.55 (95% CI 1.38-1.75) for fat-free mass and 1.30 (95% CI 1.17-1.45) for fat mass. Weighted median, Egger regression, and penalized methods showed similar estimates. The multivariate MR analysis suggested that the causal effects of fat-free and fat mass were independent of each other (causal risk ratios: 1.37, 95% CI 1.06-1.75; 1.28, 95% CI 1.03-1.58).

CONCLUSION

Genetically programmed increases in fat-free mass and fat mass independently cause an increased risk of AF.

Association of Cancer and the Risk of Developing Atrial Fibrillation: A Systematic Review and Meta-Analysis

Aims

Previous studies have demonstrated epidemiological evidence for an association between cancer and the development of new-onset atrial fibrillation (AF). However, these results have been conflicting. This systematic review and meta-analysis was conducted to examine the relationship between cancer and the risk of developing atrial fibrillation.

Methods

PubMed and Web of Science were searched for publications examining the association between cancer and atrial fibrillation risk published until June 2017. Adjusted odds ratios (ORs) or hazard ratios (HRs) and 95% CI were extracted and pooled.

Results

A total of five studies involving 5,889,234 subjects were included in this meta-analysis. Solid cancer patients are at higher risk developing atrial fibrillation compared to noncancer patients (OR 1.47, 95% CI 1.31 to 1.66, p < 0.00001; I² = 67%, p=0.02). The risk of atrial fibrillation was highest within 90 days of cancer diagnosis (OR 7.62, 95% CI 3.08 to 18.88, p < 0.00001) and this risk diminished with time.

Conclusions

The risk of AF was highest within 90 days of cancer diagnosis. We should take into account the increased risk of atrial fibrillation development and, after this, study the embolic risk and potential indication of oral anticoagulation.