CMAJ Open 2018 Jul-Sep;6(3):E308-E315. Epub 2018 Aug 2.
Libin Cardiovascular Institute of Alberta (Quinn), University of Calgary, Calgary, Alta.; Division of Neurology (Gladstone), Sunnybrook Health Sciences Centre and Sunnybrook Research Institute, and Department of Medicine, University of Toronto, Toronto, Ont.; Department of Family and Community Medicine (Ivers), Women's College Hospital - University of Toronto, Toronto, Ont.; University of Alberta (Sandhu), Edmonton, Alta.; Department of Family Medicine (Dolovich), McMaster University, Hamilton, Ont.; Population Health Research Institute (Ling, Nakamya, Ramasundarahettige, Healey), McMaster University, Hamilton, Ont.; Mount Dennis Weston Health Centre (Frydrych), Toronto, Ont.; SKDS Research Inc. (Henein), Newmarket, Ont.; Ken Ng Family Practice (Ng), Markham, Ont.; Foothills Family Medical Centre (Congdon), Black Diamond, Alta.; Department of Family Medicine (Birtwhistle), Queen's University, Kingston, Ont.; Crowfoot Village Family Practice (Ward), Calgary, Alta.
Background: Detection of undiagnosed or undertreated ("actionable") atrial fibrillation could increase the use of appropriate oral anticoagulant therapy and reduce the risk of stroke. We sought to compare newer screening technologies with a pulse-check for the detection of atrial fibrillation and to determine whether the detection of actionable atrial fibrillation increases the use of oral anticoagulant agents.
Methods: This prospective multicentre cohort study involved 22 primary care clinics. We recruited participants aged 65 years and older who were attending routine appointments. Each participant underwent 3 methods of screening: a 30-second radial pulse-check; single-lead electrocardiogram; and screening by blood pressure machine with atrial fibrillation detection algorithms. Participants who received a positive result on 1 or more test underwent 12-lead electrocardiogram with or withour 24-hour Holter. Screening tests were compared using the McNemar test. Participants with confirmed atrial fibrillation received follow-up at 90 days.
Results: The mean age of participants was 73.7 (± 6.9) years, and 53.4% of participants were female. Of 2171 patients, we had data from all 3 screening tests for 2054 patients. Both single-lead electrocardiogram and the blood pressure device showed superior specificity compared with pulse-check ( < 0.001 for each). Fifty-six patients (2.7%) had confirmed atrial fibrillation: 12 patients had newly detected atrial fibrillation (none of the patients were using anticoagulation agents), and 44 patients had previously diagnosed atrial fibrillation (42 patients were receiving anticoagulant therapy, 2 were not). Thus, 14 patients had actionable atrial fibrillation (0.7%). By 90 days, 77% of patients with actionable atrial fibrillation had started anticoagulant therapy.
Interpretation: Newer screening technologies showed superior specificity compared with a pulse-check. Screening detected undiagnosed or undertreated atrial fibrillation in 0.7% of participants, and 77% started appropriate anticoagulant therapy.
Trial Registration: ClinicalTrials.gov, no. NCT02262351.