Ethnicity and stroke risk in patients with atrial fibrillation

To examine the prevalence of atrial fibrillation (AF) and stroke risk by ethnic group in south and east London; to compare classification with CHA2DS2VASc and CHADS2; to examine the appropriateness of anticoagulant treatment and historic trends in prescribing by gender, age, and ethnicity.

Cross-sectional study.

Routine general practice records from south and east London.

Patients aged 18 years or over with AF.

Risk of stroke by CHA2DS2VASc and CHADS2 score, and prescription of anticoagulant.

In 2011, we identified 6292 patients with AF, with an age adjusted prevalence of 0.63% (1.2% white, 0.4% black African/Caribbean and 0.2% South Asian). 93% of the AF population were at high risk of stroke with a CHA2DS2VASc score ≥ 1, of whom 54% were on warfarin. South Asian patients were at higher stroke risk than white patients (OR 1.67, 95% CI 1.02 to 2.73). Warfarin under-prescribing in people over 80 years of age persisted without improvement throughout 2008-2011. There were no clear differences in warfarin use by ethnic group.

Despite a reduced prevalence of AF among South Asian patients, their risk of stroke is higher than for white patients or black African/Caribbean patients in association with diabetes, cardiovascular disease, and hypertension. Under-prescription of anticoagulation persists in all ethnic groups, a deficit most pronounced in the elderly. Use of the CHA2DS2VASc score would enhance optimal management in primary care.