Identification of patients with atrial fibrillation in general practice: a study of screening methods

Cost-effectiveness of Screening for Atrial Fibrillation Using Wearable Devices

Question

Is population-based atrial fibrillation (AF) screening using wearable devices cost-effective?

Findings

In this economic evaluation of 30 million simulated individuals with an age, sex, and comorbidity profile matching the US population aged 65 years or older, AF screening using wearable devices was cost-effective, with the overall preferred strategy identified as wearable photoplethysmography, followed conditionally by wearable electrocardiography with patch monitor confirmation (incremental cost-effectiveness ratio, $57 894 per quality-adjusted life-year). The cost-effectiveness of screening was consistent across multiple scenarios, including strata of sex, screening at earlier ages, and with variation in the association of anticoagulation with risk of stroke associated with screening-detected AF.

Meaning

This study suggests that contemporary AF screening using wearable devices may be cost-effective.

Importance

Undiagnosed atrial fibrillation (AF) is an important cause of stroke. Screening for AF using wrist-worn wearable devices may prevent strokes, but their cost-effectiveness is unknown.

Objective

To evaluate the cost-effectiveness of contemporary AF screening strategies, particularly wrist-worn wearable devices.

Design, Setting, and Participants

This economic evaluation used a microsimulation decision-analytic model and was conducted from September 8, 2020, to May 23, 2022, comprising 30 million simulated individuals with an age, sex, and comorbidity profile matching the US population aged 65 years or older.

Interventions

Eight AF screening strategies, with 6 using wrist-worn wearable devices (watch or band photoplethysmography, with or without watch or band electrocardiography) and 2 using traditional modalities (ie, pulse palpation and 12-lead electrocardiogram) vs no screening.

Main Outcomes and Measures

The primary outcome was the incremental cost-effectiveness ratio, defined as US dollars per quality-adjusted life-year (QALY). Secondary measures included rates of stroke and major bleeding.

Results

In the base case analysis of this model, the mean (SD) age was 72.5 (7.5) years, and 50% of the individuals were women. All 6 screening strategies using wrist-worn wearable devices were estimated to be more effective than no screening (range of QALYs gained vs no screening, 226-957 per 100 000 individuals) and were associated with greater relative benefit than screening using traditional modalities (range of QALYs gained vs no screening, −116 to 93 per 100 000 individuals). Compared with no screening, screening using wrist-worn wearable devices was associated with a reduction in stroke incidence by 20 to 23 per 100 000 person-years but an increase in major bleeding by 20 to 44 per 100 000 person-years. The overall preferred strategy was wearable photoplethysmography, followed conditionally by wearable electrocardiography with patch monitor confirmation, which had an incremental cost-effectiveness ratio of $57 894 per QALY, meeting the acceptability threshold of $100 000 per QALY. The cost-effectiveness of screening was consistent across multiple scenarios, including strata of sex, screening at earlier ages (eg, ≥50 years), and with variation in the association of anticoagulation with risk of stroke in the setting of screening-detected AF.

Conclusions and Relevance

This economic evaluation of AF screening using a microsimulation decision-analytic model suggests that screening using wearable devices is cost-effective compared with either no screening or AF screening using traditional methods.

Optimal opportunistic screening of atrial fibrillation using pulse palpation in cardiology outpatient clinics: Who and how

Background

Atrial fibrillation (AF) remain a prevalent undiagnosed condition frequently encountered in primary care.

Objective

We aimed to find the parameters that optimize the diagnostic accuracy of pulse palpation to detect AF. We also aimed to create a simple algorithm for selecting which individuals would benefit from pulse palpation and, if positive, receive an ECG to detect AF.

Methods

Nurses from four Cardiology outpatient clinics palpated 7,844 pulses according to a randomized list of arterial territories and durations of measure and immediately followed by a 12-lead ECG, which we used as the reference standard. We calculated the sensitivity and specificity of the palpation parameters. We also assessed whether diagnostic accuracy depended on the nurse’s experience or on a list of clinical factors of the patients. With this information, we estimated the positive predictive values and false omission rates according to very few clinical factors readily available in primary care (age, sex, and diagnosis of heart failure) and used them to create the algorithm.

Results

The parameters associated with the highest diagnostic accuracy were palpation of the radial artery and classifying as irregular those palpations in which the nurse was uncertain about pulse regularity or unable to palpate pulse (sensitivity = 79%; specificity = 86%). Specificity decreased with age. Neither the nurse’s experience nor any investigated clinical factor influenced diagnostic accuracy. We provide the algorithm to select the ≥40 years old individuals that would benefit from a pulse palpation screening: a) do nothing in <60 years old individuals without heart failure; b) do ECG in ≥70 years old individuals with heart failure; c) do radial pulse palpation in the remaining individuals and do ECG if the pulse is irregular or you are uncertain about its regularity or unable to palpate it.

Conclusions

Opportunistic screening for AF using optimal pulse palpation in candidate individuals according to a simple algorithm may have high effectiveness in detecting AF in primary care.

Comparative Clinical Effectiveness of Population-Based Atrial Fibrillation Screening Using Contemporary Modalities: A Decision-Analytic Model

Background Atrial fibrillation (AF) screening is endorsed by certain guidelines for individuals aged ≥65 years. Yet many AF screening strategies exist, including the use of wrist-worn wearable devices, and their comparative effectiveness is not well-understood. Methods and Results We developed a decision-analytic model simulating 50 million individuals with an age, sex, and comorbidity profile matching the United States population aged ≥65 years (ie, with a guideline-based AF screening indication). We modeled no screening, in addition to 45 distinct AF screening strategies (comprising different modalities and screening intervals), each initiated at a clinical encounter. The primary effectiveness measure was quality-adjusted life-years, with incident stroke and major bleeding as secondary measures. We defined continuous or nearly continuous modalities as those capable of monitoring beyond a single time-point (eg, patch monitor), and discrete modalities as those capable of only instantaneous AF detection (eg, 12-lead ECG). In total, 10 AF screening strategies were effective compared with no screening (300-1500 quality-adjusted life-years gained/100 000 individuals screened). Nine (90%) effective strategies involved use of a continuous or nearly continuous modality such as patch monitor or wrist-worn wearable device, whereas 1 (10%) relied on discrete modalities alone. Effective strategies reduced stroke incidence (number needed to screen to prevent a stroke: 3087-4445) but increased major bleeding (number needed to screen to cause a major bleed: 1815-4049) and intracranial hemorrhage (number needed to screen to cause intracranial hemorrhage: 7693-16 950). The test specificity was a highly influential model parameter on screening effectiveness. Conclusions When modeled from a clinician-directed perspective, the comparative effectiveness of population-based AF screening varies substantially upon the specific strategy used. Future screening interventions and guidelines should consider the relative effectiveness of specific AF screening strategies.

Population-Based Screening for Atrial Fibrillation

Atrial fibrillation (AF) is a common and morbid arrhythmia. Stroke is a major hazard of AF and may be preventable with oral anticoagulation. Yet since AF is often asymptomatic, many individuals with AF may be unaware and do not receive treatment that could prevent a stroke. Screening for AF has gained substantial attention in recent years as several studies have demonstrated that screening is feasible. Advances in technology have enabled a variety of approaches to facilitate screening for AF using both medical-prescribed devices as well as consumer electronic devices capable of detecting AF. Yet controversy about the utility of AF screening remains owing to concerns about potential harms resulting from screening in the absence of randomized data demonstrating effectiveness of screening on outcomes such as stroke and bleeding. In this review, we summarize current literature, present technology, population-based screening considerations, and consensus guidelines addressing the role of AF screening in practice.

"As Needed" nonvitamin K antagonist oral anticoagulants for infrequent atrial fibrillation episodes following atrial fibrillation ablation guided by diligent pulse monitoring: A feasibility study

INTRODUCTION

After atrial fibrillation (AF) ablation, oral anticoagulation (OAC) is recommended if stroke risk as assessed by CHA₂ DS ₂ -VASc score is high. However, patients without AF are often reluctant to take daily OAC. We describe outcome using as needed nonvitamin K antagonist (NOACs) guided by pulse monitoring to detect AF following successful ablation.

METHODS AND RESULTS

We identified 99 patients (84% male, age 64 ± 8 years), CHA₂ DS ₂ -VASc score greater than or equal to 1 in men and greater than or equal to 2 in women (median 2, range 1-6), capable of pulse assessment twice daily and no AF on extended monitoring after AF ablation. All patients were instructed to start NOAC if AF >1 hour or recurrent shorter episodes. Duration of NOAC use after restart was typically 2 to 4 weeks. After 30 ± 14 months (total 244 patient-years), 22 patients (22%) transitioned to daily NOAC because of noncompliance with pulse assessment or patient preference (six patients) or because of suspected or documented AF episode(s) in 16 (16%) patients. Of the remaining 77 (78%), 14 (14%) used NOACs but did not transition back to daily use, most (10 patients) with single use (seven patients) or non-AF rhythm (three patients) documented. There was only one thromboembolic event (0.4%/yr of follow-up) in patient without AF and one mild bleeding event (epistaxis).

CONCLUSION

The use of as needed NOACs when AF is suspected with pulse monitoring is effective and safe to maintain low risk of stroke and bleeding after successful ablation. Transition back to daily NOAC use should be anticipated in about one quarter of patients.

Screening to identify unknown atrial fibrillation

Atrial fibrillation (AF) is associated with a significantly increased stroke risk which is highly preventable with appropriate oral anticoagulant therapy (OAC). However, AF may be asymptomatic and unrecognised prior to stroke. We aimed to determine if single time-point screening for AF could identify sufficient numbers with previously undiagnosed AF, to be effective for stroke prevention. This is a systematic review of clinical trials, by searching electronic medical databases, reference lists and grey literature. Studies were included if they evaluated a general ambulant adult population, using electrocardiography or pulse palpation to identify AF. We identified 30 individual studies (n=122,571, mean age 64 years, 54% male) in nine countries. Participants were recruited either from general practitioner and outpatient clinics (12 studies) or population screening/community advertisements (18 studies). Prevalence of AF across all studies was 2.3% (95% CI, 2.2–2.4%), increasing to 4.4% (CI, 4.1–4.6%) in those ≥65 years (16 studies, n= 27,884). Overall incidence of previously unknown AF (14 studies, n=67,772) was 1.0% (CI, 0.89–1.04%), increasing to 1.4% (CI, 1.2–1.6%) in those ≥65 years (8 studies, n= 18,189) in whom screening setting did not influence incidence identified. Of those with previously unknown AF, 67% were at high risk of stroke. Screening can identify 1.4% of the population ≥65 years with previously undiagnosed AF. Many of those identified would be eligible for, and benefit from OAC to prevent stroke. Given this incidence, community AF screening strategies in at risk older age groups could potentially reduce the overall health burden associated with AF.

Opportunistic screening for atrial fibrillation in a real-life setting in general practice in Denmark-The Atrial Fibrillation Found On Routine Detection (AFFORD) non-interventional study

Atrial fibrillation (AF) is a chronic disease with an incidence increasing steeply by age and affecting more than 11 million patients in Europe and the United States. Diagnosing AF is essential for the prevention of stroke by oral anticoagulation. Opportunistic screening for AF in patients ≥65 years of age is recommended by the European and Danish Societies of Cardiology. The study aim was to examine the detection rate of AF in consecutively screened patients in the primary care setting in Denmark. In an open, non-interventional, cluster, multicenter, cross-sectional, observational study patients ≥65 years of age entering consecutively into general practice clinics were invited to nurse-assisted opportunistic screening for AF. The General Practice (GP) clinics participating were randomized to patient inclusion in three age groups: 65-74, 75-84, and ≥85 years respectively. All patients underwent pulse palpation followed by 12-led electrocardiogram in case of irregular pulse. Two cardiologists validated all electrocardiogram examinations. Forty-nine general practice clinics recruited in total 970 patients split into three age groups; 480 patients (65-74 years), 372 (75-84 years), and 118 patients ≥85 years of age. Co-morbidities increased by age with hypertension being most frequent. Eighty-seven patients (9%) were detected with an irregular pulse, representing 4.4%, 10.5% and 22.9%, respectively in the three age groups. Assessment of electrocardiograms by the GP showed suspicion of AF in 13 patients with final verification of electrocardiograms by cardiologists revealing 10 AF-patients. The highest detection rate of AF was found in the ≥85 age group (3.39%) followed by the 65-74 age group (0.83%) and the 75-84 age group (0.54%). Opportunistic screening of AF in primary care is feasible and do result in the detection of new AF-patients. Close collaboration with cardiologists is advisable to avoid false positive screening results.

Reliability of pulse palpation in the detection of atrial fibrillation in an elderly population

PURPOSE

Atrial fibrillation (AF) may first present as an ischemic stroke. Pulse palpation is a potential screening method for asymptomatic AF. We aimed to assess the reliability of pulse palpation by the elderly in detecting AF.

MATERIALS AND METHODS

After brief information and training session conducted by a nurse, 173 subjects aged ≥75 years were instructed to palpate their pulse regularly for a month. After this, their ability to distinguish sinus rhythm (SR), SR with premature ventricular contractions (PVC) and AF by pulse palpation was assessed using an anatomic human arm model programmable with various rhythms. A control group of 57 healthcare professionals received the same information but not the training. Subjects unable to find the pulse were excluded (25 (14.5%) of the elderly and none in the healthcare group).

RESULTS

The median age of the elderly subjects was 78.4 [3.9] years and 98 (56.6%) were women. There were no differences between the elderly and healthcare groups in detecting SR (97.3% vs. 96.5%) or SR with PVCs (74.3% vs. 71.4%), but the elderly subjects identified slow (81.8% vs. 56.1%) and fast AF (91.9% vs. 80.7%) significantly better than the healthcare group. The ability to recognize SR with PVCs by the elderly was independently predicted by previous pulse palpation experience, secondary or higher level of education and one-point increase in MMSE score, while identifying the other rhythms had no predictors.

CONCLUSIONS

The elderly can learn to reliably distinguish a normal rhythm after education. Pulse self-palpation may be a useful low-cost method to screen for asymptomatic AF.

Screening strategies for atrial fibrillation: a systematic review and cost-effectiveness analysis

Background

Atrial fibrillation (AF) is a common cardiac arrhythmia that increases the risk of thromboembolic events. Anticoagulation therapy to prevent AF-related stroke has been shown to be cost-effective. A national screening programme for AF may prevent AF-related events, but would involve a substantial investment of NHS resources.

Objectives

To conduct a systematic review of the diagnostic test accuracy (DTA) of screening tests for AF, update a systematic review of comparative studies evaluating screening strategies for AF, develop an economic model to compare the cost-effectiveness of different screening strategies and review observational studies of AF screening to provide inputs to the model.

Design

Systematic review, meta-analysis and cost-effectiveness analysis.

Setting

Primary care.

Participants

Adults.

Intervention

Screening strategies, defined by screening test, age at initial and final screens, screening interval and format of screening {systematic opportunistic screening [individuals offered screening if they consult with their general practitioner (GP)] or systematic population screening (when all eligible individuals are invited to screening)}.

Main outcome measures

Sensitivity, specificity and diagnostic odds ratios; the odds ratio of detecting new AF cases compared with no screening; and the mean incremental net benefit compared with no screening.

Review methods

Two reviewers screened the search results, extracted data and assessed the risk of bias. A DTA meta-analysis was perfomed, and a decision tree and Markov model was used to evaluate the cost-effectiveness of the screening strategies.

Results

Diagnostic test accuracy depended on the screening test and how it was interpreted. In general, the screening tests identified in our review had high sensitivity (> 0.9). Systematic population and systematic opportunistic screening strategies were found to be similarly effective, with an estimated 170 individuals needed to be screened to detect one additional AF case compared with no screening. Systematic opportunistic screening was more likely to be cost-effective than systematic population screening, as long as the uptake of opportunistic screening observed in randomised controlled trials translates to practice. Modified blood pressure monitors, photoplethysmography or nurse pulse palpation were more likely to be cost-effective than other screening tests. A screening strategy with an initial screening age of 65 years and repeated screens every 5 years until age 80 years was likely to be cost-effective, provided that compliance with treatment does not decline with increasing age.

Conclusions

A national screening programme for AF is likely to represent a cost-effective use of resources. Systematic opportunistic screening is more likely to be cost-effective than systematic population screening. Nurse pulse palpation or modified blood pressure monitors would be appropriate screening tests, with confirmation by diagnostic 12-lead electrocardiography interpreted by a trained GP, with referral to a specialist in the case of an unclear diagnosis. Implementation strategies to operationalise uptake of systematic opportunistic screening in primary care should accompany any screening recommendations.

Limitations

Many inputs for the economic model relied on a single trial [the Screening for Atrial Fibrillation in the Elderly (SAFE) study] and DTA results were based on a few studies at high risk of bias/of low applicability.

Future work

Comparative studies measuring long-term outcomes of screening strategies and DTA studies for new, emerging technologies and to replicate the results for photoplethysmography and GP interpretation of 12-lead electrocardiography in a screening population.

Study registration

This study is registered as PROSPERO CRD42014013739.

Funding

The National Institute for Health Research Health Technology Assessment programme.

Are Atrial Fibrillation Guidelines Altering Management? A Community Based Study

Background and Aims: We wanted to determine the prevalence of atrial fibrillation (AF) in a community based cross sectional study in greater Glasgow and how current anti thrombotic management compares to published guidelines. Methods: 1466 patients with AF were identified in General Practices in our community and 1008 consented to take part. Their demographic details and medical history were recorded. Results: 1466 patients (mean age 73.4; 55% female) with AF were identified, in our community, giving a prevalence of 1%. 53% of patients were on warfarin therapy. Of those not receiving warfarin, only one third had a putative contra-indication. The proportion of AF patients on warfarin increased with increasing stroke risk, and over the period of the study. Conclusions: Prevalence of AF was in keeping with previous estimates. The proportion of patients with AF receiving warfarin therapy appears to be increasing. In the moderate risk group, there was a tendency to use more warfarin in the younger age groups compared to the elderly. It was in the moderate and low risk groups that there was still evidence of deviation from published guidelines.

Systematic screening for the detection of atrial fibrillation

BACKGROUND

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

OBJECTIVES

This review aims to answer the following questions.Does systematic screening increase the detection of AF compared with routine practice? Which combination of screening population, strategy and test is most effective for detecting AF compared with routine practice? What safety issues and adverse events may be associated with individual screening programmes? How acceptable is the intervention to the target population? What costs are associated with systematic screening for AF?

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and EMBASE (Ovid) up to 11 November 2015. We searched other relevant research databases, trials registries and websites up to December 2015. We also searched reference lists of identified studies for potentially relevant studies, and we contacted corresponding authors for information about additional published or unpublished studies that may be relevant. We applied no language restrictions.

SELECTION CRITERIA

Randomised controlled trials comparing screening for AF with routine practice in people 40 years of age and older were eligible. Two review authors (PM and CT) independently selected trials for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors (PM and CT) independently assessed risk of bias and extracted data. We used odds ratios (ORs) and 95% confidence intervals (CIs) to present results for the primary outcome, which is a dichotomous variable. As we identified only one study for inclusion, we performed no meta-analysis. We used the GRADE (Grades of Recommendation, Assessment, Development and Evaluation Working Group) method to assess the quality of the evidence and GRADEPro to create a 'Summary of findings' table.

MAIN RESULTS

One cluster-randomised controlled trial met the inclusion criteria for this review. This study compared systematic screening (by invitation to have an electrocardiogram (ECG)) and opportunistic screening (pulse palpation during a general practitioner (GP) consultation for any reason, followed by an ECG if pulse was irregular) versus routine practice (normal case finding on the basis of clinical presentation) in people 65 years of age or older.Results show that both systematic screening and opportunistic screening of people over 65 years of age are more effective than routine practice (OR 1.57, 95% CI 1.08 to 2.26; and OR 1.58, 95% CI 1.10 to 2.29, respectively; both moderate-quality evidence). We found no difference in the effectiveness of systematic screening and opportunistic screening (OR 0.99, 95% CI 0.72 to 1.37; low-quality evidence). A subgroup analysis found that systematic screening and opportunistic screening were more effective in men (OR 2.68, 95% CI 1.51 to 4.76; and OR 2.33, 95% CI 1.29 to 4.19, respectively) than in women (OR 0.98, 95% CI 0.59 to 1.62; and OR 1.2, 95% CI 0.74 to 1.93, respectively). No adverse events associated with screening were reported.The incremental cost per additional case detected by opportunistic screening was GBP 337, compared with GBP 1514 for systematic screening. All cost estimates were based on data from the single included trial, which was conducted in the UK between 2001 and 2003.

AUTHORS' CONCLUSIONS

Evidence suggests that systematic screening and opportunistic screening for AF increase the rate of detection of new cases compared with routine practice. Although these approaches have comparable effects on the overall AF diagnosis rate, the cost of systematic screening is significantly greater than the cost of opportunistic screening from the perspective of the health service provider. Few studies have investigated effects of screening in other health systems and in younger age groups; therefore, caution needs to be exercised in relation to transferability of these results beyond the setting and population in which the included study was conducted.Additional research is needed to examine the effectiveness of alternative screening strategies and to investigate the effects of the intervention on risk of stroke for screened versus non-screened populations.

Accuracy of methods for detecting an irregular pulse and suspected atrial fibrillation: A systematic review and meta-analysis

Background

Pulse palpation has been recommended as the first step of screening to detect atrial fibrillation. We aimed to determine and compare the accuracy of different methods for detecting pulse irregularities caused by atrial fibrillation.

Methods

We systematically searched MEDLINE, EMBASE, CINAHL and LILACS until 16 March 2015. Two reviewers identified eligible studies, extracted data and appraised quality using the QUADAS-2 instrument. Meta-analysis, using the bivariate hierarchical random effects method, determined average operating points for sensitivities, specificities, positive and negative likelihood ratios (PLR, NLR); we constructed summary receiver operating characteristic plots.

Results

Twenty-one studies investigated 39 interventions (n = 15,129 pulse assessments) for detecting atrial fibrillation. Compared to 12-lead electrocardiography (ECG) diagnosed atrial fibrillation, blood pressure monitors (BPMs; seven interventions) and non-12-lead ECGs (20 interventions) had the greatest accuracy for detecting pulse irregularities attributable to atrial fibrillation (BPM: sensitivity 0.98 (95% confidence interval (CI) 0.92–1.00), specificity 0.92 (95% CI 0.88–0.95), PLR 12.1 (95% CI 8.2–17.8) and NLR 0.02 (95% CI 0.00–0.09); non-12-lead ECG: sensitivity 0.91 (95% CI 0.86–0.94), specificity 0.95 (95% CI 0.92–0.97), PLR 20.1 (95% CI 12–33.7), NLR 0.09 (95% CI 0.06–0.14)). There were similar findings for smartphone applications (six interventions) although these studies were small in size. The sensitivity and specificity of pulse palpation (six interventions) were 0.92 (95% CI 0.85–0.96) and 0.82 (95% CI 0.76–0.88), respectively (PLR 5.2 (95% CI 3.8–7.2), NLR 0.1 (95% CI 0.05–0.18)).

Conclusions

BPMs and non-12-lead ECG were most accurate for detecting pulse irregularities caused by atrial fibrillation; other technologies may therefore be pragmatic alternatives to pulse palpation for the first step of atrial fibrillation screening.

Triage tests for identifying atrial fibrillation in primary care: a diagnostic accuracy study comparing single-lead ECG and modified BP monitors

OBJECTIVE

New electronic devices offer an opportunity within routine primary care settings for improving the detection of atrial fibrillation (AF), which is a common cardiac arrhythmia and a modifiable risk factor for stroke. We aimed to assess the performance of a modified blood pressure (BP) monitor and two single-lead ECG devices, as diagnostic triage tests for the detection of AF.

SETTING

6 General Practices in the UK.

PARTICIPANTS

1000 ambulatory patients aged 75 years and over.

PRIMARY AND SECONDARY OUTCOME MEASURES

Comparative diagnostic accuracy of modified BP monitor and single-lead ECG devices, compared to reference standard of 12-lead ECG, independently interpreted by cardiologists.

RESULTS

A total of 79 participants (7.9%) had AF diagnosed by 12-lead ECG. All three devices had a high sensitivity (93.9-98.7%) and are useful for ruling out AF. WatchBP is a better triage test than Omron autoanalysis because it is more specific-89.7% (95% CI 87.5% to 91.6%) compared to 78.3% (95% CI 73.0% to 82.9%), respectively. This would translate into a lower follow-on ECG rate of 17% to rule in/rule out AF compared to 29.7% with the Omron text message in the study population. The overall specificity of single-lead ECGs analysed by a cardiologist was 94.6% for Omron and 90.1% for Merlin.

CONCLUSIONS

WatchBP performs better as a triage test for identifying AF in primary care than the single-lead ECG monitors as it does not require expertise for interpretation and its diagnostic performance is comparable to single-lead ECG analysis by cardiologists. It could be used opportunistically to screen elderly patients for undiagnosed AF at regular intervals and/or during BP measurement.

Self-detection of atrial fibrillation in an aged population: the LietoAF Study

BACKGROUND

Early detection of atrial fibrillation (AF) in older people is important because AF is often asymptomatic and its first manifestation may be a disabling stroke. The objective of the LietoAF Study is to assess the motivation and capability of older people to learn pulse palpation and continue regular pulse measurements, and whether this self-assessment is helpful in the detection of new AF.

DESIGN AND METHOD

The LietoAF Study is an intervention study. A total of 205 people aged ≥75 years were randomly selected to participate in the programme where a trained nurse gave individual education on pulse palpation. At 1 month, the eligible participants came to the first follow-up visit to assess the success of pulse self-monitoring.

RESULTS

A total of 139 participants (68%) learned pulse palpation and performed regular measurements during the early follow-up period. The significant independent predictors for learning and motivation were high Mini-Mental State Examination score (>24) (OR 7.5, 95% CI 1.5-37.3, p = 0.014), computer use at home (OR 4.7, 95% CI 1.9-11.5, p = 0.001), independence at daily activities (OR 4.2, 95% CI 1.4-13.6, p = 0.013) and low heart rate (OR 1.04, 95% CI 1.0-1.08, p = 0.037). Education did not cause extra visits to local healthcare centres and did not affect quality of life. Four participants observed a new asymptomatic AF during the 1-month follow-up.

CONCLUSION

Active older people are motivated and seem to learn pulse palpation. Our early experience suggests that simple nurse-based education is effective and useful in the early detection of asymptomatic AF.

Effectiveness of systematic screening for the detection of atrial fibrillation

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Accuracy of algorithms for detection of atrial fibrillation from short duration beat interval recordings

Atrial fibrillation (AF) is characterised by highly variable beat intervals. The aims of the study were to assess the accuracy of AF detection algorithms from short analysis durations and to validate prospectively the accuracy on a large community-based cohort of elderly subjects. Three algorithms for AF detection were evaluated: coefficient of variation (CV), mean successive difference (Δ) and coefficient of sample entropy (COSEn), using two databases of beat interval recordings: 167 recordings of 300 s duration for a range of rhythms acquired in a hospital setting and 2130 recordings of 10s duration acquired in the community. Using the longer recordings receiver operating characteristic (ROC) analysis was used to identify optimal algorithm thresholds and to evaluate analysis durations ranging from 5s to 60s. An ROC area of 93% was obtained at recording duration of 60s but remained above 90% for durations as low as 5s. Prospective analysis on the 2130 recordings gave AF detector sensitivities from 90.5% (CV and Δ) to 95.2% (COSEn), specificities from 89.3% (Δ) to 93.4% (COSEn) and accuracy from 89.3% (Δ) to 93.4% (COSEn), not significantly different to those obtained on the initial database. AF detection algorithms are effective for short analysis durations, offering the prospect of a simple and rapid diagnostic test based on beat intervals alone.

Mid-term results for the Maze procedure in patients with non-mitral valvular atrial fibrillation

BACKGROUND

The Maze procedure in patients without mitral valve disease remains controversial, because of the increased invasiveness and operation time required to create additional incisions in the atria. The aim of this study was to assess prognosis following the Maze procedure in patients without mitral valve disease.

METHODS AND RESULTS

One hundred and seven consecutive patients who underwent the Maze procedure between 2002 and 2008 was enrolled in this study. Patients were divided into two groups based on the presence or absence of mitral valve disease. Freedom from atrial fibrillation was compared by multivariate logistic regression analysis at discharge. The Kaplan-Meier method and Cox-proportional hazard analysis adjusted for other predictors were estimated to compare freedom from atrial fibrillation at follow-up. Follow-up was 98% complete and mean duration of follow-up was 457 days. Operation and aorta cross-clamp times were similar between groups. No differences were identified in freedom from atrial fibrillation at discharge (non-mitral valve surgery, 55% vs. mitral valve surgery, 66%) or follow-up (57% vs. 61%, respectively). In multivariate Cox proportional hazard modelling, the presence of mitral valve disease was not associated with a poor success rate of conversion.

CONCLUSIONS

Results of the Maze procedure for atrial fibrillation without mitral valve disease were acceptable. The Maze procedure could be a beneficial option for these patients to avoid adverse events of atrial fibrillation.

Study protocol: the DESPATCH study: delivering stroke prevention for patients with atrial fibrillation - a cluster randomised controlled trial in primary healthcare

Background

Compelling evidence shows that appropriate use of anticoagulation in patients with nonvalvular atrial fibrillation reduces the risk of ischaemic stroke by 67% and all-cause mortality by 26%. Despite this evidence, anticoagulation is substantially underused, resulting in avoidable fatal and disabling strokes.

Methods

DESPATCH is a cluster randomised controlled trial with concealed allocation and blinded outcome assessment designed to evaluate a multifaceted and tailored implementation strategy for improving the uptake of anticoagulation in primary care. We have recruited general practices in South Western Sydney, Australia, and randomly allocated practices to receive the DESPATCH intervention or evidence-based guidelines (control). The intervention comprises specialist decisional support via written feedback about patient-specific cases, three academic detailing sessions (delivered via telephone), practice resources, and evidence-based information. Data for outcome assessment will be obtained from a blinded, independent medical record audit. Our primary endpoint is the proportion of nonvalvular atrial fibrillation patients, over 65 years of age, receiving oral anticoagulation at any time during the 12-month posttest period.

Discussion

Successful translation of evidence into clinical practice can reduce avoidable stroke, death, and disability due to nonvalvular atrial fibrillation. If successful, DESPATCH will inform public policy, providing quality evidence for an effective implementation strategy to improve management of nonvalvular atrial fibrillation, to close an important evidence-practice gap.

Trial registration

Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12608000074392

Atrial fibrillation detection by heart rate variability in Poincare plot

BACKGROUND

Atrial fibrillation (AFib) is one of the prominent causes of stroke, and its risk increases with age. We need to detect AFib correctly as early as possible to avoid medical disaster because it is likely to proceed into a more serious form in short time. If we can make a portable AFib monitoring system, it will be helpful to many old people because we cannot predict when a patient will have a spasm of AFib.

METHODS

We analyzed heart beat variability from inter-beat intervals obtained by a wavelet-based detector. We made a Poincare plot using the inter-beat intervals. By analyzing the plot, we extracted three feature measures characterizing AFib and non-AFib: the number of clusters, mean stepping increment of inter-beat intervals, and dispersion of the points around a diagonal line in the plot. We divided distribution of the number of clusters into two and calculated mean value of the lower part by k-means clustering method. We classified data whose number of clusters is more than one and less than this mean value as non-AFib data. In the other case, we tried to discriminate AFib from non-AFib using support vector machine with the other feature measures: the mean stepping increment and dispersion of the points in the Poincare plot.

RESULTS

We found that Poincare plot from non-AFib data showed some pattern, while the plot from AFib data showed irregularly irregular shape. In case of non-AFib data, the definite pattern in the plot manifested itself with some limited number of clusters or closely packed one cluster. In case of AFib data, the number of clusters in the plot was one or too many. We evaluated the accuracy using leave-one-out cross-validation. Mean sensitivity and mean specificity were 91.4% and 92.9% respectively.

CONCLUSIONS

Because pulse beats of ventricles are less likely to be influenced by baseline wandering and noise, we used the inter-beat intervals to diagnose AFib. We visually displayed regularity of the inter-beat intervals by way of Poincare plot. We tried to design an automated algorithm which did not require any human intervention and any specific threshold, and could be installed in a portable AFib monitoring system.

Home monitoring with a modified automatic sphygmomanometer to detect recurrent atrial fibrillation

OBJECTIVES

Detecting asymptomatic atrial fibrillation would help identify patients who would benefit from anticoagulation. This study examined the application of a modified blood pressure monitor to screen for episodes of atrial fibrillation.

METHODS

A modified sphygmomanometer was designed to detect atrial fibrillation. The device has a sensitivity near 100% and a specificity of up to 91%. Therefore, this device can be expected to detect all episodes of atrial fibrillation. However, the lower specificity may result in false-positive readings that could prompt unnecessary clinic visits for electrocardiogram confirmation of the rhythm. Outpatients in sinus rhythm with a history of atrial fibrillation were given the device to monitor their pulse regularity once daily to detect atrial fibrillation. Patients with irregular readings were evaluated with an electrocardiogram.

RESULTS

Nineteen patients were monitored at home for a period ranging from 5 days to 5 months. Seven patients had recurrent atrial fibrillation identified by the monitor. Nine patients had no irregular readings for a mean of 82 +/- 40 days. Of 19 patients, 3 had false-positive irregular readings that were a result of sinus arrhythmia or ectopy.

CONCLUSIONS

The device had an acceptably low false-positive rate allowing 16 of 19 patients to use it at home for long-term atrial fibrillation monitoring. This device may help prevent strokes by identifying patients with prolonged episodes of asymptomatic atrial fibrillation who are candidates for anticoagulation.

Accuracy of diagnosing atrial fibrillation on electrocardiogram by primary care practitioners and interpretative diagnostic software: analysis of data from screening for atrial fibrillation in the elderly (SAFE) trial

OBJECTIVE

To assess the accuracy of general practitioners, practice nurses, and interpretative software in the use of different types of electrocardiogram to diagnose atrial fibrillation.

DESIGN

Prospective comparison with reference standard of assessment of electrocardiograms by two independent specialists.

SETTING

49 general practices in central England.

PARTICIPANTS

2595 patients aged 65 or over screened for atrial fibrillation as part of the screening for atrial fibrillation in the elderly (SAFE) study; 49 general practitioners and 49 practice nurses.

INTERVENTIONS

All electrocardiograms were read with the Biolog interpretative software, and a random sample of 12 lead, limb lead, and single lead thoracic placement electrocardiograms were assessed by general practitioners and practice nurses independently of each other and of the Biolog assessment.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative predictive values.

RESULTS

General practitioners detected 79 out of 99 cases of atrial fibrillation on a 12 lead electrocardiogram (sensitivity 80%, 95% confidence interval 71% to 87%) and misinterpreted 114 out of 1355 cases of sinus rhythm as atrial fibrillation (specificity 92%, 90% to 93%). Practice nurses detected a similar proportion of cases of atrial fibrillation (sensitivity 77%, 67% to 85%), but had a lower specificity (85%, 83% to 87%). The interpretative software was significantly more accurate, with a specificity of 99%, but missed 36 of 215 cases of atrial fibrillation (sensitivity 83%). Combining general practitioners' interpretation with the interpretative software led to a sensitivity of 92% and a specificity of 91%. Use of limb lead or single lead thoracic placement electrocardiograms resulted in some loss of specificity.

CONCLUSIONS

Many primary care professionals cannot accurately detect atrial fibrillation on an electrocardiogram, and interpretative software is not sufficiently accurate to circumvent this problem, even when combined with interpretation by a general practitioner. Diagnosis of atrial fibrillation in the community needs to factor in the reading of electrocardiograms by appropriately trained people.

Screening versus routine practice in detection of atrial fibrillation in patients aged 65 or over: cluster randomised controlled trial

OBJECTIVES

To assess whether screening improves the detection of atrial fibrillation (cluster randomisation) and to compare systematic and opportunistic screening.

DESIGN

Multicentred cluster randomised controlled trial, with subsidiary trial embedded within the intervention arm.

SETTING

50 primary care centres in England, with further individual randomisation of patients in the intervention practices.

PARTICIPANTS

14,802 patients aged 65 or over in 25 intervention and 25 control practices.

INTERVENTIONS

Patients in intervention practices were randomly allocated to systematic screening (invitation for electrocardiography) or opportunistic screening (pulse taking and invitation for electrocardiography if the pulse was irregular). Screening took place over 12 months in each practice from October 2001 to February 2003. No active screening took place in control practices.

MAIN OUTCOME MEASURE

Newly identified atrial fibrillation.

RESULTS

The detection rate of new cases of atrial fibrillation was 1.63% a year in the intervention practices and 1.04% in control practices (difference 0.59%, 95% confidence interval 0.20% to 0.98%). Systematic and opportunistic screening detected similar numbers of new cases (1.62% v 1.64%, difference 0.02%, -0.5% to 0.5%).

CONCLUSION

Active screening for atrial fibrillation detects additional cases over current practice. The preferred method of screening in patients aged 65 or over in primary care is opportunistic pulse taking with follow-up electrocardiography.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN19633732 [controlled-trials.com].

A patient decision aid to support shared decision-making on anti-thrombotic treatment of patients with atrial fibrillation: randomised controlled trial

OBJECTIVE

To determine the efficacy of a computerised decision aid in patients with atrial fibrillation making decisions on whether to take warfarin or aspirin therapy.

DESIGN

Two-armed open exploratory randomised controlled trial.

SETTING

Two research clinics deriving participants from general practices in Northeast England.

PARTICIPANTS

109 patients with atrial fibrillation aged over 60.

INTERVENTIONS

Computerised decision aid applied in shared decision-making clinic compared to evidence-based paper guidelines applied as direct advice.

MAIN OUTCOME MEASURES

Primary outcome measure was the decision conflict scale. Secondary outcome measures included anxiety, knowledge, decision-making preference, treatment decision, use of primary and secondary care services and health outcomes.

RESULTS

Decision conflict was lower in the computerised decision aid group immediately after the clinic; mean difference -0.18 (95% CI -0.34 to -0.01). Participants in this group not already on warfarin were much less likely to start warfarin than those in the guidelines arm (4/16, 25% compared to the guidelines group 15/16, 93.8%, RR 0.27, 95% CI 0.11 to 0.63).

CONCLUSIONS

Decision conflict was lower immediately following the use of a computerised decision aid in a shared decision-making consultation than immediately following direct doctor-led advice based on paper guidelines. Furthermore, participants in the computerised decision aid group were significantly much less likely to start warfarin than those in the guidelines arm. The results show that such an approach has a positive impact on decision conflict comparable to other studies of decision aids, but also reduces the uptake of a clinically effective treatment that may have important implications for health outcomes.

National underuse of anti-thrombotic therapy in chronic atrial fibrillation identified from digoxin prescribing

AIMS

To examine if appropriate antithrombotic therapy in atrial fibrillation is implemented nationally.

METHODS

Using prescriptions for digoxin as a surrogate for atrial fibrillation, we identified its coprescription with antithrombotic therapy, aspirin or warfarin in a national prescribing database in 27 571 patients over 45 years old.

RESULTS

Proportionately significantly more men were on warfarin, and use in those >75 years old was three times less than in those <65 years. Reluctance to use antithrombotics was confirmed in a postal survey.

CONCLUSION

Data suggest a missed opportunity to prevent stroke with women and those >75 years old least likely to receive warfarin.

Management of atrial fibrillation

Atrial fibrillation (AF) is a condition of genuine clinical concern. This arrhythmia increases patient morbidity and mortality, most notably due to stroke, thromboembolism and heart failure. Consequentially, there is a strong impetus to acquire a greater understanding of its natural history and course in order to provide crucial evidence-based treatment and resource allocation in the future. The objective of this review article is to present a concise overview of the management of AF, with reference to the recent evidence-based National Institute of Clinical Excellence (NICE) National Clinical Guidelines for the management of AF.

A community education program on atrial fibrillation: Implications of pulse self-examination on awareness and behavior

OBJECTIVES

We postulated that community groups with older demographics could be taught to find and characterize their pulse rhythm for the presence of an irregular pulse (IP), which may indicate atrial fibrillation, a major risk factor for stroke.

METHODS

We conducted 281 community group education sessions involving 6203 attendees. Awareness objectives were to demonstrate that: (1) group education was effective in establishing awareness that an IP may indicate atrial fibrillation; and (2) this message was retained at follow-up. Behavioral objectives were to: (1) assess ability of participants to find and characterize their pulse rhythm; (2) regularly monitor pulse rhythm; and (3) act with medical appropriateness upon detecting an IP.

RESULTS

Of 6203 attendees, 4322 were older than 50 years and consented to participate. Of these consenting participants, 73.2% found their radial pulse and 91% characterized the rhythm (regular, 72.1%; irregular, 11%; undetermined, 7.9%). Telephone follow-ups on 1839 participants were performed at 30 to 60 days to assess durability of message and action taken. At follow-up, 89.1% remembered that an IP is potentially a risk factor for stroke, and 70.3% had taken their pulse since the program. Of those who discovered a new IP, 38% sought medical assessment.

CONCLUSION

Community education programs focusing on pulse self-examination are effective in improving awareness that an IP may be a surrogate indicator of stroke risk. Such programs may lead to improved awareness of atrial fibrillation, subsequent behavioral changes, and stroke prevention.

Stroke prevention and atrial fibrillation: reasons leading to an inappropriate management. Main results of the SAFE II study

AIMS

The aim of the Stroke and Atrial Fibrillation Ensemble (SAFE) II study was to identify the reasons underlying the under-utilization of oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (NVAF).

METHODS

We investigated from all available sources the reasons why patients hospitalized for a stroke, who had a previously known NVAF, were not receiving OAC beforehand. We interviewed general practitioners (GPs) and cardiologists with a structured questionnaire, to identify the reasons for their therapeutic choice.

RESULTS

Of 370 patients, 257 were theoretically eligible for OAC according to guidelines and the presence of contra-indications, but only 82 (22.2%) of them had actually received OAC before. We found that factors independently associated with the prescription of OAC were being followed-up by a cardiologist and having a younger GP. The leading reason evoked by GPs or cardiologists to explain why patients were not treated with OAC was the presence of a 'potential contra-indication', which was often inappropriate, followed by 'there was no indication', 'low compliance' and 'fear of bleeding'.

CONCLUSIONS

An important reason for not prescribing OAC was the lack of knowledge about trials and guidelines. Medical education about OAC in NVAF should therefore be improved.

A randomized trial to assess the impact of an antithrombotic decision aid in patients with nonvalvular atrial fibrillation: the DAAFI trial protocol [ISRCTN14429643]

BACKGROUND

Decision aids are often advocated as a means to assist patient and health care provider decision making when faced with complicated treatment or screening decisions. Despite an exponential growth in the availability of decision aids in recent years, their impact on long-term treatment decisions and patient adherence is uncertain due to a paucity of rigorous studies. The choice of antithrombotic therapy for nonvalvular atrial fibrillation (NVAF) is one condition for which a trade-off exists between the potential risks and benefits of competing therapies, and the need to involve patients in decision making has been clearly identified. This study will evaluate whether an evidence-based patient decision aid for patients with NVAF can improve the appropriateness of antithrombotic therapy use by patients and their family physicians.

DESIGN

A multi-center, two-armed cluster randomized trial based in community family practices in which patients with NVAF will be randomized to decision aid or usual care. Patients will receive one of four decision aids depending on their baseline stroke risk. The primary outcome is the provision of "appropriate antithrombotic therapy" at 3 months to study participants (appropriateness defined as per the 2001 American College of Chest Physicians recommendations for NVAF). In addition, the impact of this decision aid on patient knowledge, decisional conflict, well-being, and adherence will be assessed after 3 months, 6 months, and 12 months.

Protocol for Birmingham Atrial Fibrillation Treatment of the Aged study (BAFTA): a randomised controlled trial of warfarin versus aspirin for stroke prevention in the management of atrial fibrillation in an elderly primary care population [ISRCTN89345269]

BACKGROUND

Atrial fibrillation (AF) is an important independent risk factor for stroke. Randomised controlled trials have shown that this risk can be reduced substantially by treatment with warfarin or more modestly by treatment with aspirin. Existing trial data for the effectiveness of warfarin are drawn largely from studies in selected secondary care populations that under-represent the elderly. The Birmingham Atrial Fibrillation Treatment of the Aged (BAFTA) study will provide evidence of the risks and benefits of warfarin versus aspirin for the prevention of stroke for older people with AF in a primary care setting.

STUDY DESIGN

A randomised controlled trial where older patients with AF are randomised to receive adjusted dose warfarin or aspirin. Patients will be followed up at three months post-randomisation, then at six monthly intervals there after for an average of three years by their general practitioner. Patients will also receive an annual health questionnaire.1240 patients will be recruited from over 200 practices in England. Patients must be aged 75 years or over and have AF. Patients will be excluded if they have a history of any of the following conditions: rheumatic heart disease; major non-traumatic haemorrhage; intra-cranial haemorrhage; oesophageal varices; active endoscopically proven peptic ulcer disease; allergic hypersensitivity to warfarin or aspirin; or terminal illness. Patients will also be excluded if the GP considers that there are clinical reasons to treat a patient with warfarin in preference to aspirin (or vice versa). The primary end-point is fatal or non-fatal disabling stroke (ischaemic or haemorrhagic) or significant arterial embolism. Secondary outcomes include major extra-cranial haemorrhage, death (all cause, vascular), hospital admissions (all cause, vascular), cognition, quality of life, disability and compliance with study medication.

Randomised trial of two approaches to screening for atrial fibrillation in UK general practice

BACKGROUND

Atrial fibrillation is a common and treatable cause of stroke that often remains unrecognised. Screening has been suggested but there is very little evidence concerning the uptake of screening in the elderly population at risk, nor of the optimal method of screening in a general practice setting

AIM

To compare the uptake and effectiveness of two methods of screening for atrial fibrillation in general practice--systematic nurse-led screening and prompted opportunistic case finding.

DESIGN OF STUDY

Randomised controlled trial.

SETTING

Patients aged 65 to 100 years (n = 3,001) from four general practices within the MRC general practice framework.

METHOD

Each of the four study practices were selected from one quartile, after ranking all framework practices according to the small area standardised mortality ratio of the geographical area served. Patients were randomised either to nurse-led screening or to prompted opportunistic casefinding. The proportion of patients assessed and the proportion found to have atrial fibrillation were compared. The sensitivity and specificity of clinical assessment of pulse are also reported.

RESULTS

Substantially more patients had their pulse assessed through systematic screening by invitation (1,099/1,499 [73%]) than through opportunistic case finding (439/1,502 [29%], difference = 44%, 95% confidence interval [CI] = 41% to 47%). Atrial fibrillation was detected in 67 (4.5%) and 19 (1.3%) patients respectively (difference = 3.2%, 95% CI= 2.0 to 4.4). Invitation to nurse-led screening achieved significantly higher assessment rates than case finding in all practices; however, the proportion of patients assessed in the case-finding arm varied markedly between practices (range = 8% to 52%). The number needed to screen to identify one additional patient with atrial fibrillation was 31 (95% CI = 23 to 50). The proportion of screened patients with atrial fibrillation receiving anticoagulation treatment was 25%, although in the majority (53/65 [82%]) atrial fibrillation had been previously recorded somewhere on their medical record. If the nurse used any irregularity of the pulse as the screening criterion, the sensitivity of screening was 91% and the specificity was 74%; sensitivity fell to 54% but specificity increased to 98% if the criterion used was continuous irregularity.

CONCLUSIONS

Nurse-led screening for atrial fibrillation in UK general practice is both feasible and effective and will identify a substantial number of patients who could benefit from antithrombotic therapy. Although the majority of patients detected at first screening could be identified by careful scrutiny of medical records, review of record summaries was insufficient in the practices involved in this study and screening may be a more cost-effective option.

Atrial fibrillation: a comparison of methods to identify cases in general practice

The importance of atrial fibrillation as a treatable risk factor for stroke is well established. Less is known about how to find previously unidentified cases within the community so that antithrombotic treatment can be offered to a wider group of at-risk patients. The aim of our study was to examine ways to improve the efficiency of practice-based screening for atrial fibrillation, including issues of time and financial cost. We used different combinations of pulse palpation and interpretation of 12-lead and bipolar electrocardiographs as carried out by practice nurses. The best strategy for the detection of atrial fibrillation in a practice population would appear to be to screen all eligible subjects by nurse pulse palpation, followed by 12-lead electrocardiograph readings in those who have a pulse suggestive of atrial fibrillation. The electrocardiograph interpretation can be undertaken effectively by a trained nurse.

Screening for atrial fibrillation in the community: A multicenter validation trial

BACKGROUND

Atrial fibrillation (AF) is an important public health problem. This arrhythmia is common and associated with a high risk of stroke. Further, appropriate interventions in AF can reduce the risk of stroke by approximately 68%. Population studies show that a large group of patients have intermittent or chronic AF that remains unrecognized. If a simple screening test for this arrhythmia could be developed and validated, application of the technique across populations might identify AF patients for early treatment, potentially reducing the incidence of stroke. In this study, we sought to determine whether individuals taken from the general community could be taught to find and classify the pulse of another as very irregular, implying AF, or regular, implying normal sinus rhythm (NSR). The aim was to establish that pulse examination for potential AF could be performed by individuals with sufficient sensitivity and specificity to be effectively used as a screening procedure for this medically important arrhythmia.

METHODS

We enrolled 178 subjects selected from the general community from four centers. Subjects received standardized education on the medical importance of AF and its signature, a very irregular pulse. A technique for palpating and characterizing the rhythm of the radial pulse was also taught. Without further coaching, subjects were then asked to find their pulse and then to find and classify the pulse of two models randomly presented who may or may not have had AF.

RESULTS

Of the 178 subjects tested, 92% were able to find their own pulse; 17 (9.6%) were unable to find the pulse of one or both patient models and were, therefore, excluded from the study. Of the remaining 161 subjects, 76% (122 of 161) correctly identified the pulse in an AF model, and 86% (139 of 161) correctly identified the pulse in an NSR model. Results did not statistically differ as a function of age, educational status, or location.

DISCUSSION

This multicenter trial established that given minimal standardized instructions, subjects from the general community can reliably and consistently find both their pulse as well as the pulse of another and to differentiate a regular pulse from a very irregular pulse. If similar educational programs were widely applied across large populations, periodic screening for AF might lead to earlier diagnosis and appropriate treatment for patients who have this major risk factor for stroke. These screening programs should be focused on the population over the age of 55 where the risk of stroke in AF increases with each decade.