The catch in atrial fibrillation detection: don't forget to treat

In The Lancet Healthy Longevity Wei Zhang and colleagues1Zhang W Chen Y Miao C-Y et al.Quarterly versus annual ECG screening for atrial fibrillation in older Chinese individuals (AF-CATCH): a prospective, randomised, controlled trial.Lancet Healthy Longev. 2021; (published onlineJuly 23.)https://doi.org/10.1016/S2666-7568(21)00138-0Summary Full Text Full Text PDF Scopus (1) Google Scholar present a randomised controlled study on atrial fibrillation screening strategies in Shanghai, China, over 2 years, and thereby provide yet more clarification on how to best screen for atrial fibrillation. Knowledge on screening for silent (asymptomatic) atrial fibrillation becomes more consolidated with increasing evidence; but the best screening setting has yet to be determined (panel): which age or (risk) population to target, which device to use, and which time intervals and time span are optimal?PanelPoints to consider for the optimal screening strategyAge•<65 years•65–74 years•≥75 yearsComorbidities•Hypertension•Sleep apnoea•A history of myocardial infarction•Obesity•Diabetes•Heart failure•Chronic obstructive pulmonary disease•Chronic kidney diseaseScreening settings•Systematic•OpportunisticDigital competence of the patient•Limited•FullDevice available•Photoplethysmography-based•Electrocardiograph-basedScreening settingsSingle time•Pulse taking•Blood pressure monitor•Photoplethysmography-based wearable•Single-lead electrocardiograph•12-lead electrocardiographRepeated snapshots•30–60 sec pulse taking•1–4 times per day: blood pressure monitor,•Photoplethysmography-based wearable,•Single-lead electrocardiograph•12-lead electrocardiographContinuous•Electrocardiograph patch (patches can be worn continuously for 7 days or 14 days, and repeated if needed)Continuous long-term•Implantable loop recorder Age •<65 years•65–74 years•≥75 years Comorbidities •Hypertension•Sleep apnoea•A history of myocardial infarction•Obesity•Diabetes•Heart failure•Chronic obstructive pulmonary disease•Chronic kidney disease Screening settings •Systematic•Opportunistic Digital competence of the patient •Limited•Full Device available •Photoplethysmography-based•Electrocardiograph-based Screening settings Single time •Pulse taking•Blood pressure monitor•Photoplethysmography-based wearable•Single-lead electrocardiograph•12-lead electrocardiograph Repeated snapshots •30–60 sec pulse taking•1–4 times per day: blood pressure monitor,•Photoplethysmography-based wearable,•Single-lead electrocardiograph•12-lead electrocardiograph Continuous •Electrocardiograph patch (patches can be worn continuously for 7 days or 14 days, and repeated if needed) Continuous long-term •Implantable loop recorder This study compares different screening strategies for atrial fibrillation using an approach of either annual single timepoint screening for 2 years, or quarterly screening at a single timepoint for 2 years, in a Chinese population using a handheld single-lead electrocardiography (ECG). The quarterly screening group was further randomly assigned at a 3:1 ratio into subgroups of quarterly screening and quarterly screening plus. In addition to quarterly recordings at months 3, 6, 9, 12, 15, 18, 21, and 24, the quarterly screening plus group had once-per-week recordings during the first month of follow-up (week 1, 2, 3, and 4). Residents aged 65 years or older from five community health centres in in urban areas of Shanghai, China, were included in this study. In this age group, opportunistic screening is recommended according to the European Society of Cardiology guidelines for atrial fibrillation with a class 1B indication.2Hindricks G Potpara T Dagres N et al.2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association of Cardio-Thoracic Surgery (EACTS).Eur Heart J. 2020; 42: 373-498Crossref Scopus (683) Google Scholar There was a high willingness to participate in the study initially, with 97·6% of 8741 individuals agreeing to participate in the trial. Of screened participants, 8240 were randomly assigned, but final adherence to the screening schedule was low and only 5517 (67·5%) of those assigned completed the study. New atrial fibrillation was detected in 43 participants within the study, and an additional 30 had atrial fibrillation detected outside of the trial. Of these 73 participants with detected atrial fibrillation, 17 (23%) were prescribed oral anticoagulant therapy. Quarterly screening detected more atrial fibrillation compared with annual screening (47 cases vs 26 cases) but quarterly screening plus initial weekly screening did not improve detection. Increased adherence to screening schedule was associated with increased detection. The study is well executed and addresses the question of optimal screening frequency in a randomised manner. It is well known, based on several screening studies, that the detection of atrial fibrillation is higher with increased monitoring.3Diederichsen SZ Haugan KJ Kronborg C et al.Comprehensive evaluation of rhythm monitoring strategies in screening for atrial fibrillation: insights from patients at risk monitored long term with an implantable loop recorder.Circulation. 2020; 141: 1510-1522Crossref PubMed Scopus (24) Google Scholar The overall detection of atrial fibrillation was surprisingly low in the study. Only 43 new cases were detected by screening within the study, potentially indicating that single timepoint ECGs with such a high temporal dispersion might be inadequate to detect a substantial proportion of atrial fibrillation, regardless if ECGs are done quarterly or yearly. In other studies, done in Chinese populations, the incidence of atrial fibrillation was higher in the screened group than in this study.4Hu WS Hsieh MH Lin CL A novel atrial fibrillation prediction model for Chinese subjects: a nationwide cohort investigation of 682 237 study participants with random forest model.Europace. 2019; 21: 1307-1312Crossref PubMed Scopus (11) Google Scholar, 5Guo Y Wang H Zhang H et al.Mobile photoplethysmographic technology to detect atrial fibrillation.J Am Coll Cardiol. 2019; 74: 2365-2375Crossref PubMed Scopus (102) Google Scholar The low overall detection in the study by Zhang and colleagues might also have been caused by the low adherence rate, particularly given that clinically detected atrial fibrillation (ie, atrial fibrillation detected outside of the trial) was also low, thereby possibly indicating drivers other than ECG measurement. The real catch here is that to avoid unwanted downstream consequences from atrial fibrillation, not only does atrial fibrillation need to be detected, but it should also be ensured that stroke-protective treatment is initiated for those with newly detected atrial fibrillation. Other studies, focusing on clinical outcomes, have managed both; that is, to detect and to treat new atrial fibrillation. One such example is the STROKESTOP study, a population-based randomised screening study for atrial fibrillation, in which new atrial fibrillation cases were detected in 3% of participants, using a screening strategy of handheld single-lead ECG twice per day for 2 weeks. In the STROKESTOP study, the initiation of oral anticoagulant therapy in patients with newly detected atrial fibrillation was 93%.6Svennberg E Engdahl J Al-Khalili F Friberg L Frykman V Rosenqvist M Mass screening for untreated atrial fibrillation: the STROKESTOP study.Circulation. 2015; 131: 2176-2184Crossref PubMed Scopus (323) Google Scholar Similarly, the REHEARSE-AF study, a randomised screening study using a single-lead ECG twice per week for 1 year, showed a high detection of atrial fibrillation (3·8%) in the screening group. All patients in the REHEARSE-AF study were initiated on oral anticoagulant therapy.7Halcox JPJ Wareham K Cardew A et al.Assessment of remote heart rhythm sampling using the alivecor heart monitor to screen for atrial fibrillation: the REHEARSE-AF study.Circulation. 2017; 136: 1784-1794Crossref PubMed Scopus (231) Google Scholar In the stepwise screening study STROKESTOP 2, the biomarker NT-proBNP was used to identify older (75 and 76 years) individuals at higher risk of atrial fibrillation, with a detection rate of 2·6%, and oral anticoagulant therapy treatment was initiated in 95% of those with newly detected atrial fibrillation. In a study done in a Chinese population, a digital follow-up of patients with newly detected atrial fibrillation using a photoplethysmography-based application was used to ensure optimal treatment of atrial fibrillation. 5Guo Y Wang H Zhang H et al.Mobile photoplethysmographic technology to detect atrial fibrillation.J Am Coll Cardiol. 2019; 74: 2365-2375Crossref PubMed Scopus (102) Google Scholar, 8Guo Y Guo J Shi X et al.Mobile health technology-supported atrial fibrillation screening and integrated care: a report from the mAFA-II trial long-term extension cohort.Eur J Intern Med. 2020; 82: 105-111Summary Full Text Full Text PDF PubMed Scopus (21) Google Scholar To make sure that a screening programme is acceptable to society, it needs not only to detect and treat a substantial amount of atrial fibrillation cases, but also to be cost-effective, and it needs to show that screening can prevent future unwanted consequences. This criteria has been suggested for atrial fibrillation screening using computerised simulations,9Aronsson M Svennberg E Rosenqvist M et al.Cost-effectiveness of mass screening for untreated atrial fibrillation using intermittent ECG recording.Europace. 2015; 17: 1023-1029Crossref PubMed Scopus (92) Google Scholar and also at the April 23, 2021 European Heart Rhythm Association Congress, where the STROKESTOP study results were presented showing a reduction in the combined endpoint of stroke, all-cause mortality, and severe bleeding in the screened population compared with a control group. So, the strategy for atrial fibrillation screening should not only be one of catch and release, but also of catch and treat! DD has received speaker honoraria from Abbott, Astra Zeneca, Bayer, Biotronik, Boehringer Ingelheim, Boston Scientific, Medtronic, Pfizer, and Zoll. ES has received lecture fees from Bayer, Bristol-Myers Squibb-Pfizer, Boehringer-Ingelheim, Merck Sharp & Dohme, and Sanofi; and and travel grants from Abbott, Astra Zeneca, Bayer, Biotronik, Boehringer Ingelheim, Boston Scientific, Medtronic, Pfizer, and Zoll. ES has received lecture fees from Bayer, Bristol-Myers Squibb-Pfizer, Boehringer-Ingelheim, Merck Sharp & Dohme, and Sanofi. Quarterly versus annual ECG screening for atrial fibrillation in older Chinese individuals (AF-CATCH): a prospective, randomised controlled trialQuarterly 30 s single-lead ECG screening was associated with a significantly higher detection rate of incident atrial fibrillation compared with annual screening, but additional once per week screenings in the first month did not yield an added predictive value. Quarterly screening might be considered in a general population at a high risk of atrial fibrillation, such as those aged 65 years and older.