Atrial fibrillation undertreated as one of the major risk factors for stroke in the UK


Despite significant improvements in stroke prevention over the past decade, and a fall in incidence and deaths, UK doctors are still undertreating one of the major risk factors-atrial fibrillation-reveals research published in BMJ Open.

The researchers base their findings on an analysis of stroke data drawn from the General Practice Research Database (GPRD) for the period 1999 to 2008. The GPRD contains long term anonymised data on three million UK primary care patients. In this study, more than 32,000 adults had a stroke, one in seven (15%) of which were fatal.

The findings show that doctors have undertreated patients with atrial fibrillation. Around one in 10 patients had been diagnosed with atrial fibrillation before their first stroke, and this group was at a significantly higher risk of death from stroke than those who did not have the condition; however, only one in four of all those with atrial fibrillation were prescribed preventive anticoagulant treatment, with no sign that more serious atrial fibrillation was being targeted.

On the other hand, women were significantly more likely to have serious atrial fibrillation than men, but they were less likely to be given anticoagulant therapy. This was prescribed for 29% of men with atrial fibrillation, but only 22% of women.

Both men and women with atrial fibrillation were more likely to be prescribed anticoagulants after a first stroke, but while this rose from 29% to 48% of men, it only rose from 22% to 35% of women.

Other key results from the study are:

Women were more likely to die of a stroke than men, even after taking account of age. The average age for a first stroke was 77 years for women and 71 years for men.

The figures showed significant improvements both in the number of new cases of stroke and in subsequent survival.

The prevalence of stroke rose by 12.5%, but the number of new cases fell by almost a third (30%) over the decade-from 1.48 per 1,000 person years in 1999 to 1.04 in 2008.

Among those aged 80 and over, who are at the highest risk of stroke, the fall was even greater, at 42%.

The rate of deaths within 56 days of a first stroke almost halved, falling from one in five (21%) in 1999 to nearly one in 10 (12%) in 2008.

These improvements were paralleled by a consistent rise in prescriptions for preventive drugs, particularly those used to lower cholesterol and high blood pressure, both of which are risk factors for stroke.

The authors conclude that primary care doctors are tackling the risk factors for stroke much more effectively. “However, there is a clear suggestion that risk stratification is not yet optimal, particularly in relation to patients with atrial fibrillation”.