Opportunistic screening for atrial fibrillation by clinical pharmacists in UK general practice during the influenza vaccination season: a cross-sectional feasibility study

Background: Growing prevalence of atrial fibrillation (AF) in the ageing population, and its associated life-changing health and resource implications, have led to a need to improve its early detection. Primary care is an ideal place to screen for AF, however this is limited by shortages in general practitioner (GP) resources. Recent increases in the number of clinical pharmacists within primary care, makes them ideally placed to conduct AF screening. This study aimed to determine the feasibility of GP practice-based clinical pharmacists to screen the over 65s for AF, using digital technology and pulse palpation during the influenza vaccination season. Methods and Findings: Screening was conducted over two influenza vaccination seasons, 2017-2018 and 2018-2019 in four GP practices in Kent, UK. Pharmacists were trained by a cardiologist to pulse palpate, record and interpret a single-lead ECG (SLECG). Eligible persons aged ≥65 years, attending an influenza vaccination clinic were offered a free heart rhythm check. 604 participants were screened (median age 73 years, 42.7% male). Total prevalence of AF was 4.3%. All participants with AF qualified for anticoagulation and were more likely to be male (57.7%); older; have an increased BMI and have a CHA2DS2-VASc (Congestive heart failure, Hypertension, Age ≥ 75, Diabetes, previous Stroke, Age 65-74 years, Sex category) score ≥ 3. The sensitivity and specificity of clinical pharmacists diagnosing AF using pulse palpation was 76.9% [95% CI: 56.4-91.0] and 92.2% [89.7-94.3], respectively. This rose to 88.5% (69.9-97.6) and 97.2% [95.5-98.4] with a SLECG. At follow-up, four participants (0.7%) were diagnosed with new AF and 3 (0.5%) were initiated on anticoagulation. Screening with SLECG also helped identify new non-AF cardiovascular diagnoses, such as left ventricular hypertrophy, in 28 participants (4.6%). The screening strategy was cost-effective in 71.8% and 64.3% of the estimates for SLECG or pulse palpation, respectively. Feedback from participants (422/604) was generally positive. Key limitations of the study were that the intervention did not reach individuals who did not attend the practice for an influenza vaccination and there was a limited representation of UK ethnic minority groups in the study cohort. Conclusions: This study demonstrates that AF screening performed by GP practice-based pharmacists was feasible, economically viable and positively endorsed by participants. Furthermore, diagnosis of AF by the clinical pharmacist using a SLECG was more sensitive and more specific than the use of pulse palpation alone. Future research should explore the key barriers preventing the adoption of national screening programmes.