Screening for atrial fibrillation in patients aged 65 years or over attending annual flu vaccination clinics at a single general practice.

BACKGROUND

Atrial fibrillation (AF) is a common, treatable cause of stroke. Screening is recommended at influenza vaccination ('flu') clinics, but not implemented nationally.

OBJECTIVES

We aimed to determine if screening for AF by pulse assessment of those aged ≥ 65 years attending flu vaccination is effective, practical and feasible. The success of screening was determined by discovery of undiagnosed cases, estimating the prevalence of undiagnosed AF, assessing the accuracy of a second-year General Practice Specialty Trainee (GPST2) and interpretative software at diagnosing AF on electrocardiography (ECG), completion without disrupting routine practice, estimating cost-effectiveness and guiding future screening.

DESIGN

Patients ≥ 65 years old attending flu clinics were screened. Patients with an irregular pulse had an ECG, with interpretation by the GPST2, interpretative automated software and a reporting service.

RESULTS

A total of 573 patients were screened, identifying 95 patients with an irregular pulse: 21 had prior AF, 5 were < 65 years old and 1 had a previous myocardial infarction (MI); 68 were invited for ECG, of whom 39 attended; 2 new cases of AF were diagnosed. Pre-screening AF prevalence was 12.2% in those aged ≥ 75 years, and 12.4% after screening. A new case was discovered for every 286 patients screened. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 100% for the GPST2 and interpretative software for ECG diagnosis of AF versus cardiological assessment. Identifying a new case cost approximately £234. Limitations included low uptake of ECG appointments, and delayed and low completion of ECGs, leading to missed AF diagnoses.

CONCLUSIONS

Screening was ineffective. ECG immediately after pulse assessment is essential. Screening was acceptable to patients but required additional resources. Age groups 65-74 and ≥ 85 years were not adequately screened using flu clinics. Novel methods screening older, non-attending patients are required. Practices should introduce annual pulse checks into chronic disease templates and prompts for those aged ≥ 65 years attending surgery. Additional screening should target practices with low AF prevalence or poor rates of opportunistic screening.