People with atrial fibrillation (AF) are at increased risk of stroke. The likelihood of stroke increases five times among those with AF, with 12,500 strokes directly attributable to AF occurring annually (National Institute for Health and Care Excellence June 2014). Here we look at the increased risk of stroke for people with atrial fibrillation (AF), explore people’s experiences of stroke and Transient Ischaemic Attack (TIA or minor stroke) and consider how anticoagulants (blood thinning medications) such as warfarin can reduce the possibility of having a stroke. We also explain why aspirin is no longer recommended as a blood thinner for people with AF.
We asked Dr Tim Holt, an academic GP to talk about the increased risk of stroke for people with AF.
We also spoke with a number of people who had experienced a Transient Ischaemic Attack (TIA or minor stroke) caused by a temporary lack of blood to part of the brain. (For more see our website on TIA and minor stroke). They described symptoms similar to stroke, including dizziness, numbness, slurred speech and detachment. Chris Y noticed his arm was ‘getting a bit numb’ and his speech was ‘gobbledy gook’ for 10-15 seconds after coming back from jogging. Unlike a full stroke, TIA/minor stroke episodes are usually resolved after a short time. They can however, increase the risk of possible further TIAs or a full stroke. As George X was told by a paramedic when he had a TIA, “Let that be a warning to you, old fellow. It’s a precursor to a main stroke.”
Stroke risk and blood thinning medication (anticoagulants)
Desire to avoid a stroke is an important focus for people with AF. Anticoagulants (medicines which thin the blood) can be effective in stroke prevention and are recommended as a treatment for AF for those people with a moderate-high risk of stroke. Anticoagulants include warfarin and the newer medications dabigatran, rivaroxaban, and apixaban. (For more see ‘Alternatives to warfarin for atrial fibrillation: the new anticoagulants’). Yet despite the benefits of taking anticoagulants to reduce stroke risk, only 45% of those who are eligible for these treatments currently receive them (National Institute for Health and Care Excellence June 2014).
Some people reported being confused by the advice given by health professionals. They felt they were sometimes given contradictory messages leaving them unsure whether to take warfarin or not.
When we interviewed people in 2012 aspirin was still considered a useful treatment to protect people with atrial fibrillation (AF) from strokes by thinning the blood. Some people we spoke to preferred taking aspirin to warfarin. For them aspirin was believed to be a simple alternative that needed no monitoring and promised fewer side effects. Yet while aspirin was widely used, some people expressed concern. Aspirin was not risk-free and could increase the risk of bleeding. Elisabeth Y experienced nose bleeds and bleeding after dental surgery. Some doubted whether aspirin was effective enough to prevent strokes. Noel spoke to doctors at an AF conference who were surprised that he was taking aspirin rather than warfarin. They told him that ‘aspirin has little or no effect on people with AF’, which, at the time, contradicted his consultant’s advice to ‘stay on aspirin’. Eileen preferred warfarin as an anticoagulant, believing that while aspirin was ‘good for heart attack victims’ it was not a sufficient anticoagulant for AF patients.