Stroke is the most important cause of morbidity and long-term disability in Europe with 15 million strokes and 5.7 million deaths per year worldwide.1 It is also the second most common cause of death and dementia, the most frequent cause of epilepsy in older people, and a frequent cause of depression.2,3
Conditions and lifestyle characteristics identified as risk factors for stroke include high blood pressure, high cholesterol, atrial fibrillation (AF), diabetes and smoking. The prevalence of AF is estimated at 1.3% of the general population and increases sharply with age. The average GP will have 20–25 cases on their personal list and can expect to diagnose at least three new cases per annum.
AF is also associated with a pro-thrombotic state five-fold increase in stroke risk.4 Risk of stroke is the same in AF patients regardless of whether they have paroxysmal or sustained AF.5,6 Cardio-embolic stroke has a 30-day mortality of 25%7 and AF-related stroke has a one-year mortality of 50%.8
Yet there is a reluctance to use anticoagulation in older people. NICE estimate that in England 191,500 people with AF are receiving oral anticoagulants (OAC) but 234,000 people with AF are still receiving aspirin.9 One study found that in high-risk patients with AF admitted with a stroke, and who were candidates for anticoagulation, most were either not taking warfarin or were sub therapeutic at the time of ischaemic stroke. Many were on no antithrombotic therapy at all. These findings should encourage greater efforts to prescribe and monitor appropriate antithrombotic therapy to prevent stroke in individuals with AF.
Watch highlights of Dr Hargroves talk at www.youtube.com/watch?v=iIQZm6-nXds
To help to assess real-world outcomes in patients with AF the International longitudinal registry of patients with atrial fibrillation at risk of stroke: Global Anticoagulant Registry in the FIELD (GARFIELD) has been set up. It aims to recruit over 4,500 patients in over 100 sites.
This could help reduce the “Wicked Paradox” that as stroke risk increases, so does aspirin use. 52% of patients with AF are treated with antiplatelet treatment such as aspirin (1796/3483) and prescription of aspirin increases steeply with increasing CHADS2 score, yet aspirin has no place in AF management.10
Warfarin too is not without its risks. The most feared complication of warfarin is intracranial haemorrhage (ICH). The novel OACs so far tested in clinical trials have all shown noninferiority compared with warfarin, with better safety, consistently limiting the number of ICH. On this basis, NICE now recommends them to be considered as alternatives to warfarin in the vast majority of patients with non-valvular AF, when used as studied in the clinical trials performed so far.
To conclude, frailty is not absolute and relative risks/benefits must be made on an individual patient basis. The novel OAC’s have some significant advantages over warfarin and should be considered in all patients.
1. Lopez AD, et al. Lancet 2006; 367: 1747–57
2: Rothwell PM, et al. Lancet 2005; 366: 1773–83
3: O’Brien JT et al. Lancet Neurol 2003 2: 89–98
4. Wolf PA, et al. Stroke 1991; 22: 983–88
5. Rosamond W, et al. Circulation. 2008; 117: e25–146
6. Hart RG, et al. J Am Coll Cardiol 2000; 35: 183–87
7. Lin H-J, et al. Stroke 1996; 27: 1760-64
8. Marini C, et al. Stroke 2005; 36: 111–19.
9. NICE Costing Report. NICE Clinical Guideline no. 36; July 2006
10. Lee S, et al. BMJ Open 2011;1: e000269