Preventing stroke in people with atrial fibrillation: a cross-sectional study.

Background: The annual stroke rate in atrial fibrillation is around 5 per cent with increased risk in those with hypertension, diabetes, left ventricular dysfunction and other cardiovascular risk factors. This study set out to identify the patients with atrial fibrillation and modifiable risk factors for stroke.

Method: Analysis of practice computer data taken from eight general practices (81 811 patients) in the south of England. 944 patients with a diagnosis of atrial fibrillation, of whom 782 (82.8 percent) were aged 65 years and over.

Results: The age standardised prevalence of diagnosed atrial fibrillation was 1.23 per cent (1.28 percent for men and 1.18 percent for women). It was much more prevalent in the older population, 8.28 percent and 6.66 percent for males and females over 65, respectively. Cardiovascular co-morbidities were more frequent with increasing age. Blood pressure (BP) was recorded in over 95 per cent of patients with atrial fibrillation though there was scope for improving control; 25 per cent of men and 31 per cent women had a BP over 150/90. Inconsistent recording of ECG and echocardiography made it hard to identify patients with left ventricular dysfunction. Forty six percent of men and 37 percent of women were either being prescribed Warfarin, or had contraindications to its use; of those on Warfarin 75.9 percent have an international normalized ratio in range. Forty four per cent were treated with aspirin. People at high risk of stroke were no more likely to be treated with Warfarin or aspirin than those at moderate risk.

Conclusions: The rate of use of Warfarin remains low, and there is scope for better recording and management of risk factors particularly BP.