Die Crux mit dem Screening

Leider ist das Thema komplexer, als die Einleitung vermuten lässt. Screening, also die Suche nach einer Krankheit bei scheinbar Gesunden, ist nämlich keineswegs zwangsläufig von Vorteil. Wenn eine frühe Diagnose nicht zu besseren Ergebnissen führt als eine späte, bietet sie keinen Vorteil. Es verlängert sich nur die Zeit, in der Betroffene in Sorge leben. Außerdem besteht die Gefahr, Krankheiten bereits in einem Stadium zu behandeln, in dem die Behandlung unnötig oder gar schädlich ist („overdiagnosis“). Viele Screening-Untersuchungen sind deshalb mit Recht umstritten, eine ausführliche und sehr gute Übersicht dazu findet sich auf den Seiten des IQWiG (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen).

Opportunistisches Screening „old school“

Ein sog. opportunistisches Screening auf VHF mittels Pulskontrolle oder EKG wird in den 2016er-Leitlinien der ESC (European Society of Cardiology) empfohlen (Klasse I-Empfehlung mit mittlerem Evidenzgrad B). Opportunistisch heißt in diesem Zusammenhang, dass die Untersuchung nicht systematisch erfolgt, sondern im Rahmen eines anderweitig begründeten Kontaktes mit dem Gesundheitssystem.

Insofern ist das Screening auf bislang unentdecktes VHF keine Erfindung von Apple, auch wenn manch‘ Medienbericht des letzten Jahres diesen Anschein erweckt. Lange vor der Apple Watch war klar, dass simples Fühlen des Pulses eine sehr gute Sensitivität von rund 94 % zur Erkennung von VHF aufweist. Diese Pulskontrolle können auch Ältere nach kurzer Anleitung zuverlässig selbstständig durchführen, was unlängst u. a. in einer finnischen und einer britischen Studie bewiesen wurde.

Für die Behandlung von Patienten, deren VHF beim opportunistischen Screening entdeckt wurde, existieren klare Empfehlungen auf Grundlage guter Studien. So wissen wir beispielsweise, dass Jüngere (<65 J.) ohne weitere Risikofaktoren von einer längerfristigen Einnahme von Blutverdünnern nicht profitieren, Ältere aber sehr wohl, insbesondere bei weiteren Risikofaktoren.

Systematisches Screening

Systematisches Screening auf VHF wird in den ESC-Leitlinien sehr viel zurückhaltender beurteilt: Nur bei >75-Jährigen oder Menschen mit hohem Schlaganfallrisiko „kann es erwogen werden“ (Klasse IIb-Empfehlung, Evidenzgrad B). Ausnahme sind Patienten nach Hirninfarkt oder TIA, hier wird systematisches Screening ausdrücklich empfohlen (Klasse I-Empfehlung, Evidenzgrad B).

Grund für diese Zurückhaltung ist die Tatsache, dass mit einer Ausweitung des Screenings auf ganze Bevölkerungsgruppen oder längere Zeiträume immer mehr beschwerdefreie Menschen mit nur sehr seltenen oder kurzen VHF-Episoden erfasst werden. In diesem Stadium wurden sie früher nicht entdeckt, sie sind demzufolge in den großen Therapiestudien auch nicht berücksichtigt. Ob unsere jetzigen Behandlungsstrategien für diese Patienten mit -wie man es heute gerne bezeichnet- ausschließlich „subklinischem“ oder „device-detected“ Vorhofflimmern gut und richtig sind, wissen wir deshalb nicht.

Wer sucht, der findet …

… und wer länger sucht, der findet mehr. Das gilt auch für Vorhofflimmern. Aus vielen Untersuchungen bei Risikopatienten wissen wir, dass ein einzelnes EKG bei 0.8-6 % von Ihnen VHF aufdeckt. Ein 24-stündiges Dauer-EKG fördert bei weiteren 2-10 % und ein 72-stündiges LZ-EKG bei nochmals 2 % Vorhofflimmern zu Tage. Ein implantierter Event-Recorder hat in der REVEAL AF study nach einem Jahr bei ca. 27 % und nach drei Jahren bei 40 % dieser Menschen Episoden von mindestens 6 Minuten Dauer aufgezeichnet.

Je intensiver und ausdauernder die Suche, umso größer also die Ausbeute. Im Zuge der verfeinerten Suchstrategien wurde aber auch immer klarer, dass in den feiner gestrickten Fangnetzen auch immer kleinere Fische hängenblieben. Und dass diese kleineren Fische nicht automatisch die gleiche Behandlung erfordern wie die früher überwiegenden dicken Exemplare. Mittlerweile wissen wir, dass Menschen mit geringer Flimmerlast auch ein geringeres Schlaganfallrisiko haben (vgl. hier, hier, hier und hier).

Ein Volk sucht nach Vorhofflimmern

Die immer intensivere Suche nach Vorhofflimmern war lange Zeit „Verschlusssache“, exklusiv betrieben von Kardiologen und einigen wenigen Neurologen. Bis das Jahr 2019 einen unübersehbaren Wandel hin zur „Demokratisierung der Diagnose“ einleitete. Plötzlich gab es eine ganze Vielfalt von Devices und Apps, die den Puls und/oder das EKG registrieren und hinsichtlich VHF analysieren konnten. Diese von mir unter dem Begriff SmartEKG zusammengefassten Technologien, allen voran die Apple Watch, bewiesen ihre Zuverlässigkeit und sollen nach dem Willen der Produzenten die Suche nach Vorhofflimmern zu einem Volkssport oder Jedermann-Grundrecht werden lassen. Aus den USA wird bereits von Tausenden berichtet, die mit den Befunden der heftig beworbenen Gadgets die Praxen von Hausärzten und Kardiologen stürmen. Den Bericht über die Apple Heart Study und die Huawei Studie betitelte die Cardio News der Deutschen Gesellschaft für Kardiologie im Dezember 2019 mit der Überschrift „Ein Volk sucht nach Vorhofflimmern“.

Aktueller Stand Anfang 2020

Außerhalb von kontrollierten Studien wird von einem Massenscreening auf Vorhofflimmern abgeraten, solange keine belastbaren Daten zum Nutzen einer Blutverdünnung bei Menschen mit ausschließlich „device-detected“ VHF vorliegen. Angesichts der Öffentlichkeitswirkung diverser Smartwatches besonders bei jungen Menschen ist es in meinen Augen allerdings illusorisch, deren Verwendung als Screening-Instrument unterbinden zu wollen. Die dabei erhobenen Befunde müssen aber mit Bedacht interpretiert werden. Auf jeden Fall unschädlich sind Empfehlungen zum Lebensstil, um VHF zu vermeiden: Übergewicht reduzieren, Blutdruck und Blutzucker im Zielbereich halten, Rauchstopp, kein übermäßiger Alkoholgenuss.

Ausblick

Erste Krankenkassen bieten Risikopatienten bereits eine finanzielle Erstattung für die Nutzung digitaler Screeningverfahren auf VHF an (siehe IKK Südwest Preventicus Heartbeats).

Anfang 2020 soll die Rekrutierungsphase für HEARTLINE beginnen. Die von Apple (Hersteller der Apple Watch) und Johnson & Johnson (Mutterkonzern von Janssen Pharmaceutical, die in den USA den Gerinnungshemmer Xarelto vertreiben) gesponsorte Studie mit geplant 180.000 Patienten soll als randomisierte Endpunktstudie klären, ob Massenscreening mit der Pulsuhr tatsächlich die Gesundheit der Betroffenen verbessert.

BACKGROUND
Current guidelines recommend at least 24 hours of electrocardiographic (ECG) monitoring after an ischemic stroke to rule out atrial fibrillation. However, the most effective duration and type of monitoring have not been established, and the cause of ischemic stroke remains uncertain despite a complete diagnostic evaluation in 20 to 40% of cases (cryptogenic stroke). Detection of atrial fibrillation after cryptogenic stroke has therapeutic implications.
METHODS
We conducted a randomized, controlled study of 441 patients to assess whether long-term monitoring with an insertable cardiac monitor (ICM) is more effective than conventional follow-up (control) for detecting atrial fibrillation in patients with cryptogenic stroke. Patients 40 years of age or older with no evidence of atrial fibrillation during at least 24 hours of ECG monitoring underwent randomization within 90 days after the index event. The primary end point was the time to first detection of atrial fibrillation (lasting >30 seconds) within 6 months. Among the secondary end points was the time to first detection of atrial fibrillation within 12 months. Data were analyzed according to the intention-to-treat principle.
RESULTS
By 6 months, atrial fibrillation had been detected in 8.9% of patients in the ICM group (19 patients) versus 1.4% of patients in the control group (3 patients) (hazard ratio, 6.4; 95% confidence interval [CI], 1.9 to 21.7; P<0.001). By 12 months, atrial fibrillation had been detected in 12.4% of patients in the ICM group (29 patients) versus 2.0% of patients in the control group (4 patients) (hazard ratio, 7.3; 95% CI, 2.6 to 20.8; P<0.001). CONCLUSIONS ECG monitoring with an ICM was superior to conventional follow-up for detecting atrial fibrillation after cryptogenic stroke. (Funded by Medtronic; CRYSTAL AF ClinicalTrials.gov number, NCT00924638.)

A national screening programme for atrial fibrillation is likely to represent a cost-effective use of resources, with systematic opportunistic screening more likely to be cost-effective than systematic population screening.

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.

BACKGROUND:
Device-detected atrial fibrillation (AF) is associated with increased risk of stroke; however, there are no clearly defined thresholds of AF burden at which to initiate oral anticoagulation (OAC). We sought to describe OAC prescription practice variation in response to new device-detected AF and the association with outcomes.
METHODS:
We performed a retrospective cohort study using data from the Veterans Health Administration linked to remote monitoring data that included day-level AF burden. We included patients with cardiac implantable electronic devices and remote monitoring from 2011 to 2014, CHA2DS2-VASc score ≥2, and no prior stroke or OAC receipt in the preceding 2 years. We determined the proportion of patients prescribed OAC within 90 days after new device-detected AF across a range of AF thresholds (≥6 minutes to >24 hours) and examined site variation in OAC prescription. We used multivariable Cox proportional hazards regressions to determine the association of OAC prescription with stroke by device-detected AF burden.
RESULTS:
Among 10 212 patients with cardiac implantable electronic devices, 4570 (45%), 3969 (39%), 3263 (32%), and 2469 (24%) had device-detected AF >6 minutes, >1 hour, >6 hours, and >24 hours, respectively. For device-detected AF >1 hour, 1712 patients met inclusion criteria (72±10 years; 1.5% female; CHA2DS2-VASc score 4.0±1.4; HAS-BLED score 2.6±1.1). The proportion receiving OAC varied based on device-detected AF burden (≥6 minutes: 272/2101 [13%]; >1 hour: 273/1712 [16%]; >6 hours: 263/1279 [21%]; >24 hours: 224/818 [27%]). Across 52 sites (N=1329 patients), there was substantial site-level variation in OAC prescription after device-detected AF >1 hour (median, 16%; range, 3%-67%; median odds ratio, 1.56 [95% credible interval, 1.49-1.71]). In adjusted models, OAC prescription after device-detected AF >24 hours was associated with reduced stroke risk (hazard ratio, 0.28; 95% CI, 0.10-0.81; P=0.02), although the propensity-adjusted model was significant when AF lasted at least 6 minutes.
CONCLUSIONS:
Among veterans with cardiac implantable electronic devices, device-detected AF is common. There is large practice variation in 90-day OAC initiation after new device-detected AF, with low rates of treatment overall, even for episodes that last >24 hours. The strongest association of OAC with reduction in stroke was observed after device-detected AF >24 hours. Randomized trials are needed to confirm these observational findings.

US-Studie 2011-2016: Die mittels Zio^XT ermittelte Flimmerlast (Dauer von VHF oder VoFla in % der 14-tägigen Monitoring-Periode) war bei 1.965 Erwachsenen im Alter von durchschnittlich 69 Jahren mit dem Schlaganfallrisiko korreliert. Das CHADS-VASc-adjustierte Risiko für einen Schlaganfall war bei einer Flimmerlast ≥11.4 % (oberes Tertial) mehr als 3-mal so hoch wie in den anderen Tertialen. Dieses Resultat war über alle demografischen und klinischen Subgruppen konsistent.

IMPORTANCE:
Atrial fibrillation is a potent risk factor for stroke, but whether the burden of atrial fibrillation in patients with paroxysmal atrial fibrillation independently influences the risk of thromboembolism remains controversial.
OBJECTIVE:
To determine if the burden of atrial fibrillation characterized using noninvasive, continuous ambulatory monitoring is associated with the risk of ischemic stroke or arterial thromboembolism in adults with paroxysmal atrial fibrillation.
DESIGN, SETTING, AND PARTICIPANTS:
This retrospective cohort study conducted from October 2011 and October 2016 at 2 large integrated health care delivery systems used an extended continuous cardiac monitoring system to identify adults who were found to have paroxysmal atrial fibrillation on 14-day continuous ambulatory electrocardiographic monitoring.
EXPOSURES:
The burden of atrial fibrillation was defined as the percentage of analyzable wear time in atrial fibrillation or flutter during the up to 14-day monitoring period.
MAIN OUTCOMES AND MEASURES:
Ischemic stroke and other arterial thromboembolic events occurring while patients were not taking anticoagulation were identified through November 2016 using electronic medical records and were validated by manual review. We evaluated the association of the burden of atrial fibrillation with thromboembolism while not taking anticoagulation after adjusting for the Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) or CHA2DS2-VASc stroke risk scores.
RESULTS:
Among 1965 adults with paroxysmal atrial fibrillation, the mean (SD) age was 69 (11.8) years, 880 (45%) were women, 496 (25%) were persons of color, the median ATRIA stroke risk score was 4 (interquartile range [IQR], 2-7), and the median CHA2DS2-VASc score was 3 (IQR, 1-4). The median burden of atrial fibrillation was 4.4% (IQR ,1.1%-17.23%). Patients with a higher burden of atrial fibrillation were less likely to be women or of Hispanic ethnicity, but had more prior cardioversion attempts compared with those who had a lower burden. After adjusting for either ATRIA or CHA2DS2-VASc stroke risk scores, the highest tertile of atrial fibrillation burden (≥11.4%) was associated with a more than 3-fold higher adjusted rate of thromboembolism while not taking anticoagulants (adjusted hazard ratios, 3.13 [95% CI, 1.50-6.56] and 3.16 [95% CI, 1.51-6.62], respectively) compared with the combined lower 2 tertiles of atrial fibrillation burden. Results were consistent across demographic and clinical subgroups.
CONCLUSIONS AND RELEVANCE:
A greater burden of atrial fibrillation is associated with a higher risk of ischemic stroke independent of known stroke risk factors in adults with paroxysmal atrial fibrillation.

Wie stellt man Vorhofflimmern fest?

Mit (teilweise abgeschätzt) ansteigender Genauigkeit kommt eine ganze Reihe erprobter Methoden in Frage, unregelmäßigen Puls festzustellen und ggf. Vorhofflimmern zu identifizieren:

1. Pulsempfindung oder Pulstasten durch den Betroffenen selbst,
2. Blutdruckmessgeräte u. ä.,
3. Pulstasten durch den geschulten Betroffenen oder medizinisches Fachpersonal,
4. Photoplethysmographische Messung mit automatischer Arrhythmie-Analyse (z. B. Smartwatch),
5. 1-Kanal-EKG ohne oder mit automatischer Arrhythmie-Analyse (z.B. Apple Watch ab Series 4, Event-Recorder),
6. Intrakardiale Signale von Schrittmachern mit automatischer Arrythmie-Analyse,
7. Langzeit-EKG (24 Std. bis 14 Tage, 1-Kanal bis 3-Kanal-EKG)
8. 12-Kanal-EKG

Behandlung

Die rechtzeitige Diagnose und Behandlung von Vorhofflimmern kann bei bestimmten Menschen helfen, Schlaganfälle und Herzmuskelschwäche zu verhindern. Dies gilt insbesondere für Patienten mit bereits erlittenen Schlaganfällen und ≥65-Jährige mit zusätzlichen Risikofaktoren wie Bluthochdruck, Zucker- oder Gefäßkrankheit. Bei <65-Jährigen ohne weitere Risikofaktoren und ohne Beschwerden ist eine spezielle Behandlung hingegen meist nicht nötig. Deshalb bietet die frühzeitige Erkennung von VHF bei diesen Menschen in der Regel auch wenig Vorteile.

„Real-Life“-Studie aus Dänemark zum Screening auf Vorhofflimmern (VHF) bei über 65-Jährigen. 970 Patienten wurden mittels Pulspalpation und (bei unregelmäßigem Puls) anschließendem 12-Kanal-EKG untersucht. Unregelmäßiger Puls war bei 4.4 % (65-74 Jahre) bzw. 10.5 % (75-84 Jahre) bzw. 22.9 % (≥85 Jahre) vorhanden, VHF wurde bei 0.83 bzw. 0.54 bzw. 3.39 % bestätigt. Allgemeinmediziner vermuteten bei 13 EKG VHF, welches von Kardiologen bei 10 EKG bestätigt wurde.

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.

Bereits 2006 kommt diese Metaanalyse dreier Studien mit insgesamt 2.385 Patienten zu dem Ergebnis, dass Pulspalpation für die Erkennung von Vorhofflimmern (VHF) eine hohe Sensitivität von im Mittel 94 % (91-100 %) bei mäßiger Spezifität von im Mittel 72 % (70-77 %) aufweist.

BACKGROUND:
Atrial fibrillation in the elderly is common and potentially life threatening. The classical sign of atrial fibrillation is an irregularly irregular pulse.
OBJECTIVE:
The objective of this research was to determine the accuracy of pulse palpation to detect atrial fibrillation.
METHODS:
We searched Medline, EMBASE, and the reference lists of review articles for studies that compared pulse palpation with the electrocardiogram (ECG) diagnosis of atrial fibrillation. Two reviewers independently assessed the search results to determine the eligibility of studies, extracted data, and assessed the quality of the studies.
RESULTS:
We identified 3 studies (2385 patients) that compared pulse palpation with ECG. The estimated sensitivity of pulse palpation ranged from 91% to 100%, while specificity ranged from 70% to 77%. Pooled sensitivity was 94% (95% confidence interval [CI], 84%-97%) and pooled specificity was 72% (95% CI, 69%-75%). The pooled positive likelihood ratio was 3.39, while the pooled negative likelihood ratio was 0.10.
CONCLUSIONS:
Pulse palpation has a high sensitivity but relatively low specificity for atrial fibrillation. It is therefore useful for ruling out atrial fibrillation. It may also be a useful screen to apply opportunistically for previously undetected atrial fibrillation. Assuming a prevalence of 3% for undetected atrial fibrillation in patients older than 65 years, and given the test’s sensitivity and specificity, opportunistic pulse palpation in this age group would detect an irregular pulse in 30% of screened patients, requiring further testing with ECG. Among screened patients, 0.2% would have atrial fibrillation undetected with pulse palpation.

Von 205 Finnen im Alter ≥75 Jahren erlernten 139 (68%) die Puls-Selbstkontrolle. Signifikante Prädiktoren für den Lernerfolg waren ein hoher Mini-Mental State Examination score (>24) (OR 7.5, 95% CI 1.5-37.3, p = 0.014), PC-Benutzung zu Hause (OR 4.7, 95% CI 1.9-11.5, p = 0.001), Unabhängigkeit bei alltäglichen Aktivitäten (OR 4.2, 95% CI 1.4-13.6, p = 0.013) und niedrige Herzfrequenz (OR 1.04, 95% CI 1.0-1.08, p = 0.037). Die Puls-Selbstkontrolle führte nicht zur vermehrten Inanspruchnahme örtlicher Einrichtungen des Gesundheitswesens und beeinträchtigte die Lebensqualität nicht. Innerhalb eines Monats entdeckten vier Teilnehmer neues asymptomatisches Vorhhofflimmern.

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.

Nach kurzer Anleitung durch eine Pflegefachkraft und 1-monatiger Puls-Selbstkontrolle konnten 173 finnische ≥75-Jährige mit vergleichbarer Zuverlässigkeit wie 57 Profis (10 Pflegefachkräfte, 17 Paramedic-Studenten im letzten Ausbilungsjahr, 15 Pflege-Studenten im letzten Ausbildungsjahr und 15 Paramedic-Studentens im vorletzten Ausbildungsjahr) zwischen Sinusrhythmus (SR), Sinusrhythmus mit Extrasystolen (SR+ES) und Vorhofflimmern (VHF) unterscheiden. 25 von ihnen (14.5 %) mussten allerdings ausgeschlossen werden, weil sie den Puls nicht tasten konnten. Bzgl. der Detektion von SR (97.3% vs. 96.5%) und SR+ES (74.3% vs. 71.4%) bestanden keine signifikanten Unterschiede, langsames VHF (81.8% vs. 56.1%) und schnelles VHF (91.9% vs. 80.7%) wurde von den älteren Menschen aber zuverlässiger detektiert als von den Profis.

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.

BACKGROUND:
Atrial fibrillation (AF) is often paroxysmal and minimally symptomatic, hindering its diagnosis. Smartwatches may enhance AF care by facilitating long-term, noninvasive monitoring.
OBJECTIVE:
This study aimed to examine the accuracy and usability of arrhythmia discrimination using a smartwatch.
METHODS:
A total of 40 adults presenting to a cardiology clinic wore a smartwatch and Holter monitor and performed scripted movements to simulate activities of daily living (ADLs). Participants‘ clinical and sociodemographic characteristics were abstracted from medical records. Participants completed a questionnaire assessing different domains of the device’s usability. Pulse recordings were analyzed blindly using a real-time realizable algorithm and compared with gold-standard Holter monitoring.
RESULTS:
The average age of participants was 71 (SD 8) years; most participants had AF risk factors and 23% (9/39) were in AF. About half of the participants owned smartphones, but none owned smartwatches. Participants wore the smartwatch for 42 (SD 14) min while generating motion noise to simulate ADLs. The algorithm determined 53 of the 314 30-second noise-free pulse segments as consistent with AF. Compared with the gold standard, the algorithm demonstrated excellent sensitivity (98.2%), specificity (98.1%), and accuracy (98.1%) for identifying irregular pulse. Two-thirds of participants considered the smartwatch highly usable. Younger age and prior cardioversion were associated with greater overall comfort and comfort with data privacy with using a smartwatch for rhythm monitoring, respectively.
CONCLUSIONS:
A real-time realizable algorithm analyzing smartwatch pulse recordings demonstrated high accuracy for identifying pulse irregularities among older participants. Despite advanced age, lack of smartwatch familiarity, and high burden of comorbidities, participants found the smartwatch to be highly acceptable.

Review aus 2017-2018 im Auftrag der Agency for Healthcare Research and Quality (AHRQ), einem dem US-Gesundheitsministerium angegliederten Institut für die Bewertung medizinischer Maßnahmen. Bewertung: Bezüglich der Vor- und Nachteile eines Screenings auf Vorhofflimmern (VHF) mittels EKG herrscht Unsicherheit. Obgleich EKG-Screening zuvor unentdecktes Vorhofflimmern detektieren kann, konnte nicht nachgewiesen werden, dass es mehr Fälle detektiert als ein opportunistisches Screening mittels Pulspalpation. Die meisten älteren Individuen mit zuvor unentdecktem VHF haben ein Schlaganfallrisiko oberhalb der Interventionsschwelle für eine Antikoagulation. Zwar kann das Schlaganfallrisiko bei VHF durch Behandlung gesenkt werden, ob dies bei asymptomatischen älteren Menschen mit lediglich beim Screening detektierten VHF zu einem besseren Gesundheitsstatus führt als eine Behandlung nur bei konventionell entdecktem oder symptomatischem VHF, ist bislang nicht durch Studien belegt.

PURPOSE:
To systematically review the evidence on screening for and stroke prevention treatment of nonvalvular atrial fibrillation (AF) in adults age 65 years or older for populations and settings relevant to primary care in the United States.
DATA SOURCES:
PubMed/MEDLINE, the Cochrane Library, and trial registries through May 24, 2017; reference lists of retrieved articles; outside experts; and reviewers, with surveillance of the literature through June 6, 2018.
STUDY SELECTION:
Two investigators selected English-language studies using a priori criteria. Eligible studies included controlled trials of screening for or treatment of AF, controlled prospective cohort studies evaluating detection rates of previously unknown AF or harms of screening or treatment, and systematic reviews of trials evaluating benefits or harms of treatment. Eligible screening tests included electrocardiogram (ECG) screening (e.g., 12-lead ECG, intermittent handheld ECG) or screening with both pulse palpation and ECG for all participants. Eligible treatment studies compared warfarin, aspirin, or novel oral anticoagulants (NOACs: apixaban, dabigatran, edoxaban, or rivaroxaban) with placebo or no treatment. Studies focused on persons younger than age 65 or those with a history of stroke, transient ischemic attack, known heart disease, or heart failure were excluded.
DATA EXTRACTION:
One investigator extracted data and a second checked accuracy. Two reviewers independently rated quality for all included studies using predefined criteria.
DATA SYNTHESIS:
Seventeen unique studies (described in 22 publications) were included. No eligible studies evaluated screening compared with no screening and focused on health outcomes. Systematic screening with ECG identified more new cases of AF than no screening (absolute increase with 12-lead ECG, 0.6% [0.1% to 0.98%] over 12 months; absolute increase with twice-weekly single-lead ECG, 2.8% [95% CI, 0.9% to 4.7%] over 12 months), but a systematic approach using ECG did not detect more cases than an opportunistic approach focused on pulse palpation. Warfarin treatment for an average of 1.5 years was associated with a reduced risk of ischemic stroke (pooled relative risk [RR], 0.32 [0.20 to 0.51]) and all-cause mortality (pooled RR, 0.68 [0.50 to 0.93]), and an increased risk of major bleeding (pooled RR, 1.8 [0.85 to 3.7]) compared with controls (5 trials; 2,415 participants). Treatment trial participants were not screen-detected; mean age was 67 to 74 years; very few had a history of TIA or stroke (3%-8%); most had long-standing persistent AF; and baseline stroke risk scores were not reported. For a population of 1,000 adults age 65 or older with an annual stroke risk of 4 percent, this translates to an absolute reduction of 28 ischemic strokes and 16 deaths per year and an absolute increase of five major bleeding events per year. Aspirin treatment for an average of 1.5 years was associated with a reduced risk of ischemic stroke (pooled RR, 0.76 [0.52 to 1.1]) and all-cause mortality (pooled RR, 0.84 [0.62 to 1.14]) compared with controls, but the differences were not statistically significant (3 trials; 2,663 participants). A network meta-analysis found that all treatments reduced the risk of a composite outcome (any stroke and systemic embolism) and all-cause mortality. For NOACs, it found statistically significant associations with reduction in the composite outcome compared with placebo/control (adjusted odds ratios [ORs] from 0.32 to 0.44), and an increased risk of bleeding compared with placebo/control (adjusted ORs from 1.38 to 2.21), but confidence intervals for the risk of bleeding were wide and differences between groups were not statistically significant.
LIMITATIONS:
This review is limited in the ability to describe the direct evidence on the effectiveness or harms of screening for AF because we identified no eligible studies that aimed to address the overarching question. For potential harms of screening (e.g., overdiagnosis from misinterpretation of ECGs, subsequent interventions leading to harms), no eligible studies provided information that allowed comparison between screening and no-screening. No eligible stroke prevention treatment studies focused on asymptomatic, screen-detected participants. The included trials that evaluated warfarin benefits and harms had an average of 1.5 years of followup and were stopped early. Estimates for benefits and harms of lifelong anticoagulation and for screen-detected persons were not available.
CONCLUSIONS:
There is uncertainty about the benefits and harms of screening for AF with ECG. Although screening with ECG can detect previously unknown cases of AF, it has not been shown to detect more cases than opportunistic screening that is focused on pulse palpation. Most older adults with previously unknown AF have a stroke risk above the threshold for anticoagulation. Multiple treatments for AF reduce the risk of stroke and all-cause mortality, and increase the risk of bleeding, but trials have not assessed whether treatment of screen-detected asymptomatic older adults results in better health outcomes than treatment after detection by usual care or after symptoms develop.

Ergebnisse aus der REVEAL AF study: Bei 385 Patienten im Alter von durchschnittlich 71.5 Jahren wurde mittels implantiertem Event-Recorder innerhalb eines Jahres bei 27.1 % Vorhofflimmern > 6 Min. Dauer festgestellt. Mit konventionellen Methoden lag die Erkennungsrate für solche Episoden zwischen 0.8 % (einmaliges 24-Std.-LZ-EKG) und 10.6 % (7-Tage-LZ-EKG alle 3 Monate).

BACKGROUND:
Reducing atrial fibrillation (AF)-related stroke requires timely AF diagnosis, but the optimal monitoring strategy is unknown.
OBJECTIVE:
We used insertable cardiac monitor (ICM) data from the REVEAL AF study to compare AF detection rates by various short-term continuous monitoring (STM) strategies.
METHODS AND RESULTS:
Patients without known AF, but with CHADS2 scores ≥3 (or = 2 with ≥1 additional AF risk factor) received an ICM for AF detection. One-time STM strategies were assessed by computing AF incidence at 1, 2, 7, 14, and 30 days post-ICM insertion. Repeated STM strategies (quarterly 24-hour, 48-hour, 7-day, or monthly 24-hour monitoring) were modeled by randomly selecting day(s) within a 30-day window around each nominal evaluation date over a 1-year period (simulated 10,000 times). Endpoints included AF ≥6 minutes, AF ≥1 hour, and daily AF burden ≥1 and ≥ 5.5 hours. The impact of compliance on AF detection was evaluated using daily compliance rates of 85%, 75%, 65% and 55% during follow-up months 1-3, 4-6, 7-9, and 9-12, respectively. Based on data from 385 patients (71.5 ± 9.9 years; CHADS2 score 3.0 ± 1.0) the incidence of AF ≥6 minutes via ICM at 12 months was 27.1% (95% CI, 22.5-31.5%). This exceeded the range of estimated rates from all modeled one-time and repeated STM strategies (0.8% for 24-hour Holter monitoring to 10.6% for quarterly 7-day monitoring). Findings were similar for all AF endpoints. Modeled non-compliance reduced AF detection by 4.5% to 22.9%.
CONCLUSIONS:
Most AF episodes detected via ICMs would go undetected via conventional STM strategies, thus preventing optimal prophylaxis for adverse consequences.