If you have been diagnosed with atrial fibrillation (AF), you may have heard that it can raise your chances of having a stroke. But why does this happen, and what can be done about it? This article explains the link between AF and stroke in plain terms, and looks at why research into new AF treatments matters so much.
What Is Atrial Fibrillation?
Atrial fibrillation is a condition where the upper chambers of the heart beat in an irregular, sometimes very fast way, instead of in a steady rhythm. In the UK, around 1.4 million people live with AF. It is the most common type of heart rhythm problem.
AF does not always cause obvious symptoms. Some people feel their heart racing or fluttering, while others have no symptoms at all and only find out they have the condition during a routine check-up.
Why Does AF Increase the Risk of Stroke?
The connection between AF and stroke comes down to how blood moves through the heart.
When the heart beats normally, blood flows smoothly in and out of its chambers. When AF causes the upper chambers to quiver rather than beat properly, blood can slow down and pool inside the heart. When blood pools like this, it is more likely to clump together and form a clot.
If a blood clot forms in the heart, it can be carried through the bloodstream to the brain. If the clot gets stuck in a blood vessel in the brain and blocks the blood supply, this causes a stroke.
Strokes caused by AF tend to be more serious than those caused by other reasons. They are more likely to cause significant damage to the brain and to have lasting effects on a person’s life.
Research from the Stroke Association shows that AF is one of the most significant risk factors for stroke, and that people with AF who have a stroke are more likely to be severely affected than those without AF. You can read more on the Stroke Association’s AF and stroke page.
How Much Does AF Raise Stroke Risk?
The increase in stroke risk caused by AF is significant. People with AF are estimated to be up to five times more likely to have a stroke than people without the condition. The exact level of risk varies from person to person depending on several factors, including age, blood pressure, and whether other health conditions are present.
Doctors often use a scoring system to work out an individual’s stroke risk. This helps them decide on the right treatment.
| Risk Factor | Why It Matters |
| Age (especially over 65) | Risk increases significantly with age |
| High blood pressure | Puts extra strain on blood vessels |
| History of stroke or TIA | Indicates existing vulnerability |
| Heart failure | Combined with AF, raises risk further |
| Diabetes | Can affect blood vessel health |
| Being female | Slightly higher lifetime risk when combined with AF |
What Treatments Help Reduce the Risk?
The most common way to lower the risk of a blood clot forming is through anticoagulant medication, sometimes called blood thinners. These medicines do not dissolve existing clots, but they make it harder for new clots to form in the first place.
There are different types of anticoagulant available. The most commonly used in recent years are called direct oral anticoagulants (DOACs). These are generally easier to manage than older options and do not require as many regular blood tests.
Anticoagulants are not suitable for everyone. Doctors will weigh up the benefits of reducing stroke risk against the small increase in bleeding risk that comes with taking these medicines. This is why an individual assessment is so important.
Other treatments focus on controlling the heart rate or rhythm. These include medicines, cardioversion (a procedure to restore a normal heart rhythm), and in some cases, a procedure called catheter ablation. Lifestyle changes, such as reducing alcohol intake, maintaining a healthy weight, and managing blood pressure, can also help.
Why Research Into New AF Treatments Matters
Although there are effective treatments for AF, they do not work equally well for everyone. Some people continue to experience symptoms or remain at higher risk of stroke even when taking medication. This is why clinical trials into new AF treatments are so important.
Clinical trials test new medicines, devices, and approaches to care in a safe and closely monitored setting. The results help doctors understand which treatments work best and for whom. To find out more about how this process benefits patients, read our article on why clinical trials are so important.
For a broader look at what AF feels like and how 4MCS supports people through research, see our guide to AF symptoms and clinical trials at 4MCS.
Taking Part in an AF Clinical Trial in Manchester
4MCS runs an AF clinical trial in Manchester at our Swinton clinic in Greater Manchester. If you have been diagnosed with atrial fibrillation and are not currently taking medication for it, you may be eligible to take part.
Participating in a trial with 4MCS is straightforward. Our team has over 130 years of combined experience in clinical research, and we work hard to make sure every participant feels comfortable and well-informed throughout the process. Travel expenses are covered, and there is no charge for taking part.
If you would like to find out whether you qualify, get in touch with us by calling 03300 575 838 or emailing info@4mcs.co.uk.
