Blood clotting marker could help GPs predict stroke risk
Government-funded research has shown a blood test widely used in hospitals to detect blood clots could also help GPs identify patients with
atrial fibrillation who are at highest risk of stroke.
The test measures levels of D-dimer, a protein present in blood when clots develop.
The study showed patients with D-dimer levels in the highest 20 per cent were nine times more likely to suffer a stroke and three times more likely to have a cardiac event compared to those with levels in the lowest 20 per cent.
Researchers said laboratory- based D-dimer tests were widely used by hospital doctors to rule out deep vein thrombosis.
Experts have now to decide whether this, rather than other new tests for clinical markers to predict stroke risk, should be made available to GPs.
The prospective study at the University of Glasgow reviewed the treatment of 1,055 patients with atrial fibrillation from 36 general practices against Scottish Intercollegiate Guidelines Network guidelines published in 1999.
Improvements in warfarin prescribing were observed, with 71 per cent of newly
diagnosed atrial fibrillation patients receiving the therapy in 2001/2 compared with 59 per cent in 1999. But only half of atrial fibrillation patients aged over 75 were receiving warfarin despite the majority having no contraindications.
Blood samples were taken to assess the relevance of different clinical risk markers, including levels of D-dimer.
Study co-author Professor Gordon Lowe, chair of
SIGN and professor of vascular medicine at the University of Glasgow, said this was the first study to demonstrate markers for blood clotting
activity could also predict stroke risk.
The study, published earlier this month on the Scottish Executive website, said: 'Addition of this simple and widely available D-dimer test to existing stroke risk calculating systems may help clinicians identify those patients at highest risk of stroke.'
It added: 'Such patients could then be targeted for more intense antithrombotic treatment with the aim of lowering their D-dimer level and hopefully their subsequent risk of stroke.'
Professor Francesco Cappuccio, professor of primary care research and development at St George's Hospital Medical School in London, welcomed the results but said it was too early to predict when the test would be available to GPs.