Stepwise screening of atrial fibrillation in a 75-year-old population: implications for stroke prevention

Documentation of atrial fibrillation prior to first-ever ischemic stroke

OBJECTIVES

We assessed the prevalence of atrial fibrillation (AF) prior to first-ever ischemic stroke by examining a comprehensive electronic ECG archive.

METHODS

The study sample comprised 336 consecutive stroke patients (median age 76 (IQ16) y, 200 men) enrolled in Lund Stroke Register from March 2001 to February 2002 and 336 age- and gender-matched controls without stroke history. AF prior to admission was studied using the regional electronic ECG database and record linkage with the National Swedish Hospital Discharge Register (SHDR). Medical records were reviewed for AF documentation and CHA2 DS2-VASc risk score.

RESULTS

Atrial fibrillation before or at stroke onset was detected in 109 (32.4%) stroke patients and 44 (13.1%) controls, P<0.001. Twenty-five of 109 stroke patients had AF detected only on previous ECG (n=14) or through the SHDR (n=11). The most prevalent type of AF in stroke group was non-permanent AF (59.6%). AF prevalence among patients admitted with sinus rhythm at hospital admission (n=266) was higher in those with CHA2 DS2 -VASc score≥6 (28.6%) than with CHA2 DS2-VASc score<6 (13.0%), P=0.043.

CONCLUSION

Comprehensive approach for AF screening allows detecting AF in one-third of patients admitted with first-ever ischemic stroke. Patients with high cardiovascular risk are more likely to have non-permanent AF.

Intermittent short ECG recording is more effective than 24-hour Holter ECG in detection of arrhythmias

Background

Many patients report symptoms of palpitations or dizziness/presyncope. These patients are often referred for 24-hour Holter ECG, although the sensitivity for detecting relevant arrhythmias is comparatively low. Intermittent short ECG recording over a longer time period might be a convenient and more sensitive alternative. The objective of this study is to compare the efficacy of 24-hour Holter ECG with intermittent short ECG recording over four weeks to detect relevant arrhythmias in patients with palpitations or dizziness/presyncope.

Methods

Design: prospective, observational, cross-sectional study. Setting: Clinical Physiology, University Hospital. Patients: 108 consecutive patients referred for ambiguous palpitations or dizziness/presyncope. Interventions: All individuals underwent a 24-hour Holter ECG and additionally registered 30-second handheld ECG (Zenicor EKG® thumb) recordings at home, twice daily and when having cardiac symptoms, during 28 days. Main outcome measures: Significant arrhythmias: atrial fibrillation (AF), paroxysmal supraventricular tachycardia (PSVT), atrioventricular (AV) block II–III, sinus arrest (SA), wide complex tachycardia (WCT).

Results

95 patients, 42 men and 53 women with a mean age of 54.1 years, completed registrations. Analysis of Holter registrations showed atrial fibrillation (AF) in two patients and atrioventricular (AV) block II in one patient (= 3.2% relevant arrhythmias [95% CI 1.1–8.9]). Intermittent handheld ECG detected nine patients with AF, three with paroxysmal supraventricular tachycardia (PSVT) and one with AV-block-II (= 13.7% relevant arrhythmias [95% CI 8.2–22.0]). There was a significant difference between the two methods in favour of intermittent ECG with regard to the ability to detect relevant arrhythmias (P = 0.0094). With Holter ECG, no symptoms were registered during any of the detected arrhythmias. With intermittent ECG, symptoms were registered during half of the arrhythmia episodes.

Conclusions

Intermittent short ECG recording during four weeks is more effective in detecting AF and PSVT in patients with ambiguous symptoms arousing suspicions of arrhythmia than 24-hour Holter ECG.

The Impact of Early Detection of Atrial Fibrillation on Stroke Outcomes

Early detection of atrial fibrillation (AF) before an AF-related stroke potentially allows for prevention, but the best methods are uncertain. Population screening trials have demonstrated the ability to increase detection in older individuals by systematic screening. The subset of patients with implantable cardiac rhythm management devices are at particular risk. Remote monitoring has substantially reduced the time to detection. Although primary prevention of stroke is a priority, detection in patients with cryptogenic stroke represents another opportunity for therapeutic intervention. Evidence that early detection actually leads to improved stroke outcomes is still being gathered.

Cryptogenic Stroke: When and How Should You Look for Arrhythmias?

This article outlines current evidence and indications for electrocardiographic monitoring in documenting subclinical atrial fibrillation (AF) in patients with cryptogenic stroke. Longer monitoring improves detection rates of subclinical AF. Incorporation of risk factors predicting patients at higher risk of stroke can be used to target populations suitable for longer-term monitoring. Although longer duration of AF is expected to increase the risk of stroke, the exact cutoff for duration of clinical significance is not yet established. It seems probable that a combination of clinical risk factors and duration of AF will provide the best prediction of future clinical stroke.

Exploring the Potential Role of Catheter Ablation in Patients with Asymptomatic Atrial Fibrillation: Should We Move away from Symptom Relief?

Although silent atrial fibrillation (AF) accounts for a significant proportion of patients with AF, asymptomatic patients have been excluded from AF ablation trials. This population presents unique challenges to disease management. Recent evidence suggests that patients with asymptomatic AF may have a different risk profile and even worse long-term outcomes compared to patients with symptomatic AF. For the same reasons they might be more prone to side-effects of antiarrhythmic drugs, including pro-arrhythmias. The poor correlation between symptoms and AF demonstrated in several studies should caution physicians against making clinical decisions depending on symptoms. Although current guidelines recommend AF ablation only in patients with symptoms, more attention should be paid to the AF burden and a rhythm control strategy has the potential to improve morbidity and mortality in AF patients. However, limited data exist regarding the use of catheter ablation for asymptomatic AF patients. As ablation techniques have improved, AF ablation has become more widespread and complication rate decreased. As a result, referrals of asymptomatic patients for catheter ablation of AF are on the rise. In this review we discuss the many unresolved questions concerning the role of the ablative approach in asymptomatic patients with AF.

Uptake of atrial fibrillation screening aiming at stroke prevention: geo-mapping of target population and non-participation

Background

In a screening study for silent atrial fibrillation (AF), which is a frequent source of cardiac emboli with ischemic stroke, the proportion of non-participants was considerable and their clinical profile differed from the participants’ profile. We intended to geo-map the target population and non-participation in an attempt to understand factors related to screening uptake and, thereby, obtain useful information needed to intervene for improved uptake.

Method

In the municipality of Halmstad, Sweden, all residents born in 1934–1935 were invited to the screening study during April 2010 to February 2012. The total study group included 848 participants and 367 non-participants from 12 parishes. Geo-maps displaying participation, along with target-population-based geo-maps displaying proportion of immigrants and ischemic stroke incidence, were used.

Results

Smoothed non-participation ratios (SmNPR) varied from 0.81 to 1.24 across different parishes (SmNRP = 1 corresponds to the expected participation based on the total study group). Among high risk individuals, the geographical variation was more pronounced (SmNPR range 0.75–1.51). Two parishes with higher share of immigrants and elevated population-based ischemic stroke incidence showed markedly lower participation, particularly among high-risk individuals.

Conclusion

AF screening uptake varied evidently between parishes, particularly among high-risk individuals. Geo-mapping of target population and non-participation yielded useful information needed to intervene for improved screening uptake.

Projections on the number of individuals with atrial fibrillation in the European Union, from 2000 to 2060

AIMS

Since atrial fibrillation (AF) is associated with increased risks of cardiovascular and cerebrovascular complications, estimations on the number of individuals with AF are relevant to healthcare planning. We aimed to project the number of individuals with AF in the Netherlands and in the European Union from 2000 to 2060.

METHODS AND RESULTS

Age- and sex-specific AF prevalence estimates were obtained from the prospective community-based Rotterdam Study. Population projections for the Netherlands and the European Union were obtained from the European Union's statistics office. In the age stratum of 55-59 years, the prevalence of AF was 1.3% in men (95% CI: 0.4-3.6%) and 1.7% in women (95% CI: 0.7-4.0%). The prevalence of AF increased to 24.2% in men (95% CI: 18.5-30.7%), and 16.1% in women (95% CI: 13.1-19.4%), for those >85 years of age. This age- and sex-specific prevalence remained stable during the years of follow-up. Furthermore, we estimate that in the European Union, 8.8 million adults over 55 years had AF in 2010 (95% CI: 6.5-12.3 million). We project that this number will double by 2060 to 17.9 million (95% CI: 13.6-23.7 million) if the age- and sex-specific prevalence remains stable.

CONCLUSION

We estimate that from 2010 to 2060, the number of adults 55 years and over with AF in the European Union will more than double. As AF is associated with significant morbidities and mortality, this increasing number of individuals with AF may have major public health implications.

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.

[Diagnosis of atrial fibrillation. From the standard ECG to analysis of electrograms]

The early diagnosis of asymptomatic atrial fibrillation is important because of the associated risk for arterial embolism. Routine ECG recording, however, is not effective in asymptomatic patients. The goal of this article is to show the general practitioner and internist how the search for atrial fibrillation can be made more efficacious. For example, recording an ECG in patients older than 65 years with irregularities in their pulse or repeated ECG recording in patients older than 75 years with hypertension shows improved results in this regard. It is interesting that elements of the CHA2DS2-VASc score, which was developed to predict risk for arterial embolism, are also effective for defining populations to screen for atrial fibrillation. In the subgroup of patients with a pacemaker or implantable converter-defibrillator (ICD), histograms or intracardiac electrograms can be used to identify previously undiagnosed atrial fibrillation. The general practitioner should take these results which are usually obtained by a cardiologist into consideration in the follow-up treatment of his or her patients.

[Atrial fibrillation: current recommendations for diagnosis and treatment]

Atrial fibrillation (AF) is by far the most common arrhythmia. It occurs more often with increasing age. Patients with AF almost always require oral anticoagulants and a rate-control treatment. In addition, other cardiovascular diseases must also be carefully treated in order to reduce the risks of cardiovascular complications from AF. Most patients profit from rate-control treatment with drugs that slow the conduction of the electrical impulse through the AV node. The aim is a resting heart rate of 100-110/min. If patients suffer from AF whilst on optimal rate control therapy, rhythm-control treatment with antiarrhythmic drugs, cardioversion or catheter ablation is indicated. The choice of the rhythm-control therapy should be made based on safety considerations. Whether achieving sinus rhythm beyond improvement of symptoms improves the prognosis of AF is tested in ongoing trials.