1. ResultsIntroduction Atrial Fibrillation (AF) affects 1.2% 1 of the population and 10% of those over the age of 75 2 It is the commonest arrhythmia in primary care 3 AF increases the likelihood of stroke or Transient Ischemic Attack (TIA) by 500% 1 17% of strokes can in some way be attributed to AF 1 A recent meta-analysis showed that warfarin is substantially more efficacious by approximately 40% than anti-platelet therapy in stroke prevention 4 Systems for quantifying stroke risk It is vital to assess the stroke risk of every AF patient to determine whether they would benefit from thromboprophylactic treatment The National Institute for Clinical Excellence (NICE) has formulated a stroke risk algorithm which draws on the presence of risk factors to stratify patients into low, moderate or high risk categories 3 The main limitation of the NICE algorithm is the need for physician discretion when deciding what action to take for those in the ‘moderate risk’ category. In this instance, a quantitative tool that generated a numerical score of stroke risk would be more useful in deciding which treatment would be appropriate in AF One such tool is the CHADS-2 5 scoring system Why use the CHADS-2 scoring system in this audit? It is a quantitative investigation tool that is useful for audit purposes The point scoring system explicitly decides whether to anticoagulate those at moderate risk of stroke, and does not leave it to individual practitioner’s discretion Its efficacy in predicting future risk of stroke in AF patients has been proven 5,6 The CHADS-2 criteria: Congestive Heart Failure (1 point) History of Hypertension (1 point) Age > 75 (1 point) Diabetes (1 point) Stroke/TIA (2 points) Warfarin therapy is indicated in any patient with a CHADS-2 Score ≥2. Stroke risk increases with higher CHADS-2 scores 5,6Objective The entire AF population of one practice was audited in order to determine whether patients with a significant stroke risk are being managed with warfarin therapy where it is indicated according to the ‘CHADS-2’ criteria Those patients not on warfarin but likely benefit from it were offered a consultation to discuss its use, with the aim of referring the patient for anticoagulation if applicable and reducing stroke risk in the individual Atrial Fibrillation and Stroke Prevention in Primary Care Nicola Higgins and Holly Merris Supervisor: Dr A Haire Method An audit of the practice population at Lichfield Street Surgery in Walsall, West Midlands was carried out. Those on the practice AF register were identified using Egton Medical Information Systems (EMIS) software Patients not documented as receiving warfarin were identified as possible candidates for therapy Patients were excluded from risk stratification if they had: 1. Documented return to sinus rhythm but remained on the AF register 2. Contraindications to warfarin therapy 3. Declined warfarin therapy in the last 12 months 4. A forthcoming appointment with their GP about commencing warfarin Using medical records a CHADS-2 score was calculated for each patient Those with a CHADS-2 score ≥ 2 were sent a letter to their home address explaining that they may benefit from warfarin therapy. They were invited to the surgery for a non-urgent consultation with a General Practitioner of their choice to discuss starting warfarin 4 weeks after letters had been sent, the practice population was re-audited to determine the impact of the intervention Results 137 patients at the practice were coded as having AF 59% were already receiving appropriate anticoagulation with warfarin in the first stage of the audit cycle 32% of those not receiving anticoagulation had not declined warfarin the last year, did not have any contraindications to warfarin therapy and had a CHADS-2 score  2. This made them potentially suitable candidates for anticoagulation On completion of the audit cycle, 5 patients in total were referred for anticoagulation after a consultation with their General Practitioner. This constituted 9% of those not receiving anticoagulation at the beginning of the audit 2 patients were treated as being lost to follow-up, with the death of one patient during the audit process, and one patient not attending for a consultation regarding anticoagulation Discussion Of the 56 patients not originally on warfarin, 5 patients (9%) had been referred for anticoagulation by the end of the audit cycle. This represents a group of patients whose stroke risk had not been adequately identified and treated The lack of anticoagulation in these 5 patients before the audit could be due to the ambiguity of the NICE guidelines about whether to anticoagulate those at moderate stroke risk, or it could mean that risk stratification had not even been considered This identifies a need to risk stratify every patient with AF in primary care. This should be documented and updated regularly 10 out of the 56 patients not taking warfarin (18%) had reverted to sinus rhythm; this was identified either in the notes in the initial audit, or when the patient was invited to a consultation. This highlights the need for keeping and maintaining accurate disease registers, in accordance with the Quality and Outcomes Framework Recommendations Checking the pulse of patients with AF every time they attend the practice would help to keep the AF register up to date The CHADS-2 scoring system is an easy to use, objective scheme which has proven accuracy in predicting stroke risk in AF. If combined with the NICE guidelines it would be a useful screening tool in primary care for identifying patients who would benefit from thromboprophylaxis Key points Atrial Fibrillation is a major risk factor contributing to stroke The literature shows that warfarin is superior to anti-platelet therapy in stroke prevention The absolute benefits of anti-thrombotic therapy depend on the underlying risk of stroke; so it is useful to thoroughly assess stroke risk in AF patients in primary care This can be achieved with a system such as the CHADS-2 acronym CHADS-2 has been used as the stroke risk stratification scheme in this audit; successfully identifying those patients most suitable for anticoagulation Limitations Patients were excluded from the audit if there was an apparent contraindication to warfarin recorded in their notes. However, these contraindications were not investigated fully and may no longer have been an active problem. Therefore some patients may have been excluded from the audit unnecessarily A positive end point was defined as referral for a specialist cardiology opinion about warfarin therapy. The outcome of these referrals is unknown Reference 7 137 patients on the AF register On warfarin?81 Return to sinus rhythm documented in notes? 6 Excluded due to contraindication? 16 Warfarin declined in last 12 months? 4 CHADS-2 score ≥2?12 Warfarin offered?1 Attended for GP appointment? 1 Yes No Outcome: No longer in AF: 4 Warfarin contraindicated: 2 Warfarin declined: 5 Referred for anticoagulation: 5 56 50 34 30 18 17 Died before letter sent 16 Figure 1: Warfarin status of patients on the AF register Figure 3: Outcomes of patients invited to surgery for warfarin consultation Figure 2: Of those patients not on warfarin, what proportion would be suitable candidates for therapy?