Incremental yield of ECG screening repeated annually over 4 years in an adult Japanese population without prior atrial fibrillation: a retrospective cohort study

Abstract

ObjectivesInternational guidelines recommend opportunistic screening for atrial fibrillation (AF); however, there is no current data to inform how often to repeat screening. We aimed to investigate the incremental annual yield and stroke risk of new AF cases in individuals screened annually over 4 years.DesignA retrospective cohort study.SettingHokuriku Health Service Association, Toyama prefecture, Japan.ParticipantsEmployees and their families receiving annual health examinations from Hokuriku Health Service Association.InterventionEach subject received an annual health examination (including 12-lead ECG) from 2014 to 2017. Only subjects with baseline ECGs in 2012 and/or 2013 were included.Main outcome measuresRates (cases/100 person-years) of new AF identified each year for 4 consecutive years of screening (stratified according to gender and age groups). Calculated stroke risk of new AF cases using modified CHA2DS2-VASc scores (without heart failure data) (CHA2DS2VASc = C: congestive heart failure [1 point]; H: hypertension [1 point]; A2: age 65-74 years [1 point] or age ≥75 years [2 points]; D: diabetes mellitus [1 point]; S: prior stroke or transient ischemic attack [2 points]; VA: vascular disease [1 point]; and Sc: sex category [female] [1 point])ResultsIn 2014, 88 218 subjects had an ECG (46.8±12.5 years; 64% men): identifying 346 (0.39%) known AF and 69 (0.08%) new AF. The incidence rate of new AF increased with age from 0.01% (<50 years) to 0.98% (≥75 years) and was higher in men (0.1%) than women (0.05%). Repeated annual screening over 4 years identified a consistent new AF yield 0.06%–0.10% per year (0.33%–0.55% ≥65 years). Forty-two per cent of all new AF cases, and 76% of cases aged ≥65 years, had a class-1 oral anticoagulation (OAC) recommendation (modified CHA2DS2-VASc score ≥2 men, ≥3 women).ConclusionsRepeated annual ECG screening of the same population provides a consistent yield of new AF each year. The majority of new AF (≥65 years) are eligible for anticoagulation for stroke prevention. Although AF prevalence and incidence are lower in Japan than Western countries, 2318 new cases would be identified in Toyama prefecture each year with annual screening, of whom ~927 would have a high stroke risk with a recommendation for OAC therapy.

Baseline and Postprocedural Health Status Outcomes in Contemporary Patients With Atrial Fibrillation Who Underwent Catheter Ablation: A Report from the Japanese Outpatient Registry

“… 21 In addition, in Japan, employers have a legal obligation to provide annual health examinations that include a 12‐lead ECG to employees and their families. 22 For nonemployed or retired residents, the government provides access to annual health examinations, although attendance is optional. Therefore, patients diagnosed at medical screening would be less likely to be symptomatic, have a severe substrate, and have impaired HRQoL, than those diagnosed at the clinic or emergency room.…”

Incidence of atrial fibrillation in elderly patients with type 2 diabetes mellitus

“…However, several studies suggested the existence of racial differences in the risk of AF. For example, one previous report from Japan suggested a lower incidence of AF in Japanese people as compared with western populations 12. Consistent with this notion, it has been reported that a single screening of subjects over 65 years of age from western countries was likely to yield 1.44% persons with new- onset AF,13 whereas a study from Japan reported identifying new-onset AF in only 0.45% (95% CI 0.30% to 0.64%) of persons with a mean age of 65 years and above 12.…”

“…For example, one previous report from Japan suggested a lower incidence of AF in Japanese people as compared with western populations 12. Consistent with this notion, it has been reported that a single screening of subjects over 65 years of age from western countries was likely to yield 1.44% persons with new- onset AF,13 whereas a study from Japan reported identifying new-onset AF in only 0.45% (95% CI 0.30% to 0.64%) of persons with a mean age of 65 years and above 12. Considering that previous studies consistently reported a 1.3-fold to 1.6-fold higher risk of AF in patients with T2D,9 10 the incidence rate of AF in our elderly patients with T2D (5.14/1000 PY) seemed quite consistent with previous reports.…”

Atrial Fibrillation Detected by Single Time-Point Handheld Electrocardiogram Screening and the Risk of Ischemic Stroke

“…Similar results were reported on annual repeat screening in Japan. 23 The STROKESTOP study showed incremental yield with more intensive screening using twice daily, handheld ECG recordings for 2 weeks. 16 Given that AF is often paroxysmal, repeated or more intensive screening is likely to diagnose more AF than single time-point screening, but the stroke risk may be lower, especially with long-term continuous recordings.…”