Introduction Atrial fibrillation (AF) is the most prevalent arrhythmia in primary and secondary healthcare settings. Thromboembolic (TE) risk assessment and initiation of anti-thrombotic or anticoagulation (AT/AC) therapy, according to level of risk, is recommended in both national and international guidelines. NICE guidance stratifies patients with AF in to low, moderate or high risk categories and recommends “aspirin”, “aspirin or warfarin” or “warfarin” therapy respectively. ACC/ESC guidance endorses use of the CHADS2 scoring system and for scores of 0, 1, or ≥2 recommends “aspirin”, “aspirin or warfarin” or “warfarin” therapy respectively. In addition, it is recommended that AF episode frequency or subtype (paroxysmal (PAF), persistent (PersAF) or chronic (CAF)) does not influence TE risk assessment. We audited UK cardiologists and general practitioners (GPs) to assess adherence to these guidelines.
Methods We designed an audit questionnaire assessing: (1) use of risk stratification tools, (2) choice of AT/AC for increasing levels of risk, and (3) choice of therapy for a number of hypothetical patients with variable TE risk and variable AF subtype. The questionnaire was distributed by electronic or postal mail to 1176 cardiologists and 621 randomly selected GPs.
Results In total, 421 responses were received (306 cardiologists, 115 GPs). Overall, 91.4% of responders reported use of TE risk stratification tools (97.1% cardiologists, 76.5% GPs, p<0.001). NICE risk assessment is used by 26.6% of responders (24.5% cardiologists, 32.2% GPs, p=0.14), CHADS2 by 79.3% (90.2% cardiologists, 50.0% GPs, p<0.001). The frequency of reported use of AT/AC for each risk level of the NICE assessment and CHADS2 score are shown in Abstract 147 tables 1 and 2 respectively. Type of AF (PAF/PersAF/CAF) reportedly influences the use of AT/AC for 34.3% or responders (24.2% cardiologists, 46.3% GPs, p=0.001). Abstract 147 figure 1 demonstrates AT/AC usage for each of the following hypothetical patients: 1. 61 year old, hypertension, PAF episodes twice a year lasting 1–2 h (NICE risk: mod, CHADS2 score 1/6). 2. 43 year old, diabetes, PAF episodes weekly lasting 10–12 h (NICE risk: mod, CHADS2 score 1/6). 3. 53 year old, hypertension, CAF (NICE risk: mod, CHADS2 score 1/6). 4. 78 year old, no other risk factors, CAF (NICE risk: mod, CHADS2 score 1/6). 5. 76 year old, hypertension, diabetes, PAF episodes 3–4 times per year lasting <1 hour (NICE risk: high, CHADS2 score 3/6). 6. 77 year old, hypertension, diabetes, PAF episodes occurring weekly and lasting several hours (NICE risk: high, CHADS2 score 3/6). 7. 80 year old, previous TIA, CAF (NICE risk: high, CHADS2 score 3/6).
Conclusions TE risk stratification tools are reportedly widely used in UK clinical practice. AT/AC use for NICE and CHADS2 risk levels are mostly appropriate, although warfarin is under recommended for patients with a CHADS2 score of 2/6. In addition, the use of AT/AC is influenced, inappropriately, by AF episode frequency and subtype.
- Atrial fibrillation