Jocasta Ball

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

BACKGROUND Atrial fibrillation (AF) represents an increasing public health challenge with profound social and economic implications. METHODS A comprehensive synthesis and review of the AF literature was performed. Overall, key findings from 182 studies were used to describe the indicative scope and impact of AF from an individual to population perspective. RESULTS There are many pathways to AF including advancing age, cardiovascular disease and increased levels of obesity/metabolic disorders. The reported population prevalence of AF ranges from 2.3%-3.4% and historical trends reflect increased AF incidence. Estimated life-time risk of AF is around 1 in 4. Primary care contacts reflect whole population trends: AF-related case-presentations increase from less than 0.5% in those aged 40 years or less to 6-12% for those aged 85 years or more. Globally, AF-related hospitalisations (primary or secondary diagnosis) showed an upward trend (from ~35 to over 100 admissions/10,000 persons) during 1996 to 2006. The estimated cost of AF is greater than 1% of health care expenditure and rising with hospitalisations the largest contributor. For affected individuals, quality of life indices are poor and AF confers an independent 1.5 to 2.0-fold probability of death in the longer-term. AF is also closely linked to ischaemic stroke (3- to 5-fold risk), chronic heart failure (up to 50% develop AF) and acute coronary syndromes (up to 25% develop AF) with consistently worse outcomes reported with concurrent AF. Future projections predict at least a doubling of AF cases by 2050. SUMMARY AF represents an evolving, global epidemic providing considerable challenges to minimise its impact from an individual to whole society perspective.

Mild cognitive impairment in high-risk patients with chronic atrial fibrillation: a forgotten component of clinical management?

Objective We examined cognitive function in older hospitalised patients with chronic atrial fibrillation (AF). Design A prospective substudy of a multicentre randomised trial of an AF-specific disease management intervention (the Standard versus Atrial Fibrillation spEcific managmenT studY; SAFETY). Setting Three tertiary referral hospitals within Australia. Patients A total of 260 patients with chronic AF: mean age 72±11 years, 53% men, mean CHA2DS2-VASc score 4±2. Interventions Cognitive function was assessed at baseline (during inpatient stay) using the Montreal Cognitive Assessment (MoCA). Main Outcome Measures The extent of mild cognitive impairment (MCI—defined as a MoCA score <26) in AF patients and identification of independent predictors of MCI. Results Overall, 169 patients (65%, 95% CI 59% to 71%) were found to have MCI at baseline (mean MoCA score 21±3). Multiple deficits in cognitive domains were identified, most notably in executive functioning, visuospatial abilities and short-term memory. Predictors of MCI (age and sex-adjusted) were lower education level (technical/trade school level OR 6.00, 95% CI 2.07 to 17.42; <8 years school education OR 5.29, 95% CI 1.95 to 14.36 vs 8–13 years), higher CHA2DS2-VASc score (OR 1.46, 95% CI 1.23 to 1.74) and prescribed digoxin (OR 2.19, 95% CI 1.17 to 4.10). Conclusions MCI is highly prevalent amongst typically older high-risk patients hospitalised with AF. Routine assessment of cognitive function with adjustment of clinical management is indicated for this patient group.

Standard versus atrial fibrillation-specific management strategy (SAFETY) to reduce recurrent admission and prolong survival: pragmatic, multicentre, randomised controlled trial

BACKGROUND Patients are increasingly being admitted with chronic atrial fibrillation, and disease-specific management might reduce recurrent admissions and prolong survival. However, evidence is scant to support the application of this therapeutic approach. We aimed to assess SAFETY--a management strategy that is specific to atrial fibrillation. METHODS We did a pragmatic, multicentre, randomised controlled trial in patients admitted with chronic, non-valvular atrial fibrillation (but not heart failure). Patients were recruited from three tertiary referral hospitals in Australia. 335 participants were randomly assigned by computer-generated schedule (stratified for rhythm or rate control) to either standard management (n=167) or the SAFETY intervention (n=168). Standard management consisted of routine primary care and hospital outpatient follow-up. The SAFETY intervention comprised a home visit and Holter monitoring 7-14 days after discharge by a cardiac nurse with prolonged follow-up and multidisciplinary support as needed. Clinical reviews were undertaken at 12 and 24 months (minimum follow-up). Coprimary outcomes were death or unplanned readmission (both all-cause), measured as event-free survival and the proportion of actual versus maximum days alive and out of hospital. Analyses were done on an intention-to-treat basis. The trial is registered with the Australian New Zealand Clinical Trials Registry (ANZCTRN 12610000221055). FINDINGS During median follow-up of 905 days (IQR 773-1050), 49 people died and 987 unplanned admissions were recorded (totalling 5530 days in hospital). 127 (76%) patients assigned to the SAFETY intervention died or had an unplanned readmission (median event-free survival 183 days [IQR 116-409]) and 137 (82%) people allocated standard management achieved a coprimary outcome (199 days [116-249]; hazard ratio 0·97, 95% CI 0·76-1·23; p=0·851). Patients assigned to the SAFETY intervention had 99·5% maximum event-free days (95% CI 99·3-99·7), equating to a median of 900 (IQR 767-1025) of 937 maximum days alive and out of hospital. By comparison, those allocated to standard management had 99·2% (95% CI 98·8-99·4) maximum event-free days, equating to a median of 860 (IQR 752-1047) of 937 maximum days alive and out of hospital (effect size 0·22, 95% CI 0·21-0·23; p=0·039). INTERPRETATION A post-discharge management programme specific to atrial fibrillation was associated with proportionately more days alive and out of hospital (but not prolonged event-free survival) relative to standard management. Disease-specific management is a possible strategy to improve poor health outcomes in patients admitted with chronic atrial fibrillation. FUNDING National Health and Medical Research Council of Australia.

Women versus men with chronic atrial fibrillation: insights from the Standard versus Atrial Fibrillation spEcific managemenT studY (SAFETY)

Background Gender-based clinical differences are increasingly being identified as having significant influence on the outcomes of patients with cardiovascular disease (CVD), including atrial fibrillation (AF). Objective To perform detailed clinical phenotyping on a cohort of hospitalised patients with chronic forms of AF to understand if gender-based differences exist in the clinical presentation, thrombo-embolic risk and therapeutic management of high risk patients hospitalised with chronic AF. Methods We are undertaking the Standard versus Atrial Fibrillation spEcific managemenT studY (SAFETY) - a multi-centre, randomised controlled trial of an AF-specific management intervention versus usual care. Extensive baseline profiling of recruited patients was undertaken to identify gender-specific differences for risk delineation. Results We screened 2,438 patients with AF and recruited 335 into SAFETY. Of these, 48.1% were women who were, on average, 5 years older than their male counterparts. Women and men displayed divergent antecedent profiles, with women having a higher thrombo-embolic risk but being prescribed similar treatment regimens. More women than men presented to hospital with co-morbid thyroid dysfunction, depression, renal impairment and obesity. In contrast, more men presented with coronary artery disease (CAD) and/or chronic obstructive pulmonary disease (COPD). Even when data was age-adjusted, women were more likely to live alone (odds ratio [OR] 2.33; 95% confidence interval [CI] 1.47 to 3.69), have non-tertiary education (OR 2.69; 95% CI 1.61 to 4.48) and be symptomatic (OR 1.93; 95% CI 1.06 to 3.52). Conclusion Health care providers should be cognisant of gender-specific differences in an attempt to individualise and, hence, optimise the management of patients with chronic AF and reduce potential morbidity and mortality.

Estimating the current and future prevalence of atrial fibrillation in the Australian adult population

Objective: To estimate the current and future prevalence of atrial fibrillation (AF) in the Australian adult population according to age and sex.

A systematic review and meta-analysis of primary prevention programmes to improve cardio-metabolic risk in non-urban communities

INTRODUCTION Although cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) prevention programmes have been effective in urban residents, their effectiveness in non-urban settings, where cardio-metabolic risk is typically elevated, is unknown. We systematically reviewed the effectiveness of primary prevention programmes aimed at reducing risk factors for CVD/T2DM, including blood pressure, body mass index (BMI), blood lipid and glucose, diet, lifestyle, and knowledge in adults residing in non-urban areas. METHODS Twenty-five manuscripts, globally, from 1990 were selected for review (seven included in the meta-analyses) and classified according to: 1) study design (randomised controlled trial [RCT] or pre-/post-intervention); 2) intervention duration (short [<12months] or long term [≥12months]), and; 3) programme type (community-based programmes or non-community-based programmes). RESULTS Multiple strategies within interventions focusing on health behaviour change effectively reduced cardio-metabolic risk in non-urban individuals. Pre-/post-test design studies showed more favourable improvements generally, while RCTs showed greater improvements in physical activity and disease and risk knowledge. Short-term programmes were more effective than long-term programmes and in pre-/post-test designs reduced systolic blood pressure by 4.02mmHg (95% CI -6.25 to -1.79) versus 3.63mmHg (95% CI -7.34 to 0.08) in long-term programmes. Community-based programmes achieved good results for most risk factors except BMI and (glycated haemoglobin) HbA1c. CONCLUSION The setting for applying cardio-metabolic prevention programmes is important given its likelihood to influence programme efficacy. Further investigation is needed to elucidate the individual determinants of cardio-metabolic risk in non-urban populations and in contrast to urban populations.

Impact of Nurse-Led, Multidisciplinary Home-Based Intervention on Event-Free Survival Across the Spectrum of Chronic Heart Disease: Composite Analysis of Health Outcomes in 1226 Patients From 3 Randomized Trials

Background— We sought to determine the overall impact of a nurse-led, multidisciplinary home-based intervention (HBI) adapted to hospitalized patients with chronic forms of heart disease of varying types. Methods and Results— Prospectively planned, combined, secondary analysis of 3 randomized trials (1226 patients) of HBI were compared with standard management. Hospitalized patients presenting with heart disease but not heart failure, atrial fibrillation but not heart failure, and heart failure, as well, were recruited. Overall, 612 and 614 patients, respectively, were allocated to a home visit 7 to 14 days postdischarge by a cardiac nurse with follow-up and multidisciplinary support according to clinical need or standard management. The primary outcome of days-alive and out-of-hospital was examined on an intention-to-treat basis. During 1371 days (interquartile range, 1112–1605) of follow-up, 218 patients died and 17 917 days of hospital stay were recorded. In comparison with standard management, HBI patients achieved significantly prolonged event-free survival (90.1% [95% confidence interval, 88.2–92.0] versus 87.2% [95% confidence interval, 85.1–89.3] days-alive and out-of-hospital; P=0.020). This reflected less all-cause mortality (adjusted hazard ratio, 0.67; 95% confidence interval, 0.50–0.88; P=0.005) and unplanned hospital stay (median, 0.22 [interquartile range, 0–1.3] versus 0.36 [0–2.1] days/100 days follow-up; P=0.011). Analyses of the differential impact of HBI on all-cause mortality showed significant interactions (characterized by U-shaped relationships) with age (P=0.005) and comorbidity (P=0.041); HBI was most effective for those aged 60 to 82 years (59%–65% of individual trial cohorts) and with a Charlson Comorbidity Index Score of 5 to 8 (36%–61%). Conclusions— These data provide further support for the application of postdischarge HBI across the full spectrum of patients being hospitalized for chronic forms of heart disease. Clinical Trial Registration— URL: http://www.anzctr.org.au. Unique identifiers: 12610000221055, 12608000022369, 12607000069459.

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.

Post-discharge electrocardiogram Holter monitoring in recently hospitalised individuals with chronic atrial fibrillation to enhance therapeutic monitoring and identify potentially predictive phenotypes.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia managed in clinical practice. Maintenance of intended rate or rhythm control following hospitalisation is a key therapeutic goal. Aims: The purpose of this study was to assess post-discharge maintenance of intended AF control and classify potentially predictive heart rate (HR) phenotypes via electrocardiogram (ECG) Holter monitoring. Methods: In a sub-study of a multicentre randomised controlled trial comparing AF-specific management with usual care, 24-hour ECG Holter monitoring was undertaken in 133 patients 7–14 days post-discharge. Intended rate and rhythm control were compared to Holter data. Analysis of the frequency distribution of mean hour-to-hour differences identified those with labile HRs. Results: Mean age was 71±10 years, 67 (50%) were male and mean HR was 72±14 bpm. Most (89%) had persistent AF (median time in AF=39% (IQR 0–100%)). Uncontrolled HR (>90 bpm for >10% of recording) occurred in 35 (26%) patients and 49 (37%) patients did not achieve their intended rate (n=26) or rhythm control (n=23). Patients in the upper quartile of mean hour-to-hour HR variability were identified as persistently labile (n=33). A further group (n=22) with periodically labile HRs was identified. Those with coronary artery disease (OR 0.34; 95% CI 0.13–0.91, p=0.033) or renal disease/dysfunction (OR 0.24; 95% CI 0.06–0.98, p=0.047) were less likely to demonstrate HR stability (n=78). Conclusion: Post-discharge ECG Holter monitoring of AF patients represents a valuable tool to identify deviations in intended rhythm/rate control and adjust therapeutic management accordingly. It may also identify individuals who demonstrate labile HRs.

Atrial fibrillation is associated with cognitive decline in stroke-free subjects: the Tromsø Study

Previous studies have shown associations between atrial fibrillation (AF) and cognitive decline. We investigated this association in a prospective population study, focusing on whether stroke risk factors modulated this association in stroke‐free women and men.