Blood-thinning drugs may reduce dementia risk in people with irregular heartbeats

 Medical, News  Comments Off on Blood-thinning drugs may reduce dementia risk in people with irregular heartbeats
Oct 302017
 

“Common blood thinning drugs halve the risk of dementia for patients who have an irregular heartbeat,” reports the Mail Online.

Researchers in Sweden used the country’s health registry data to assess whether people with a condition called atrial fibrillation were less likely to get dementia if they took drugs like warfarin.

Atrial fibrillation (AF) is a heart condition that causes an irregular and often abnormally fast heartbeat. This can make the blood more likely to clot, which can lead to a stroke.

Most people with AF are prescribed anticoagulant drugs, which reduce the blood’s ability to clot.

Anticoagulants are often referred to as “blood-thinning drugs”, but this is technically incorrect as they don’t affect the density of blood.

People with AF are also at more risk of dementia, probably because of a build-up of tiny clots in the small blood vessels of the brain.

This study showed people with AF who were prescribed anticoagulants within a month of diagnosis had a 29% lower risk of getting dementia, compared with those not given the prescription.

But because of the type of study, the researchers can’t prove that anticoagulants are the reason for the reduced risk.

Still, as the researchers point out, the possible reduction in dementia risk is another reason to keep taking anticoagulant drugs if you’re prescribed them.

You shouldn’t take anticoagulants if you’re not at risk of blood clots as they can increase your risk of bleeding.

Where did the story come from?

The study was carried out by researchers at Danderyds University Hospital in Stockholm, Sweden.

It was published in the peer-reviewed European Heart Journal on an open access basis, making it free to read online.

Among the UK media, only the Sun pointed out that the study can’t prove cause and effect. The Sun’s headline described anticoagulant treatment as a “2p Alzheimer’s buster”, which is unfortunate – the type of dementia likely to be most affected by blood clots is not Alzheimer’s disease, but vascular dementia.

All the media used the more impressive 48% risk reduction figure from the study, which came from looking at people who took the drugs for most of the time, compared with people who never took them.

The more usual scientific standard is to use an intention to treat analysis of the figures, which gives a risk reduction of 29%.

Finally, The Guardian’s headline could have made it clearer that any reported dementia risk reduction only applied to people diagnosed with atrial fibrillation and not the population at large.

What kind of research was this?

This retrospective cohort study used data from Swedish health registries.

This type of study can help researchers spot patterns and links between factors (in this case anticoagulant drugs and dementia) but can’t prove that one thing (the drugs) causes another (the lower dementia risk).

That’s because researchers can’t rule out the effect of confounding factors that may influence the results.

What did the research involve?

Researchers looked at the records of all patients diagnosed with AF in Sweden from 2006 to 2014, excluding those who already had dementia.

They looked at who was prescribed anticoagulants within 30 days of diagnosis and who was diagnosed with dementia during an average of around 3 years of follow-up.

After adjusting for confounding factors, they calculated the risk of stroke for people with or without anticoagulant prescriptions.

The researchers used a statistical technique called propensity scoring to try to even out confounding factors of why some people did and others didn’t take anticoagulants despite all having a diagnosis of AF.

This is a suitable step to take, as compliance problems (not taking medication as instructed) are a known issue in some AF patients. They say this allowed them to make matched comparisons between the groups.

They also tested anticoagulant use with unconnected outcomes like falls, flu, diabetes and chronic obstructive pulmonary disorders (COPD).

They said that if anticoagulants were linked to any of them, this would indicate there may be an underlying confounding factor they hadn’t accounted for.

This would mean they wouldn’t be confident making any association between anticoagulants and dementia risk.

What were the basic results?

The researchers found:

  • 26,210 of the 444,106 people in the study group got dementia – a rate of 1.73 dementia cases per 100 people each year
  • people who’d started anticoagulants shortly after AF diagnosis were 29% less likely to get dementia (hazard ratio [HR] 0.71, 95% confidence interval [CI] 0.69 to 0.74)
  • there was no difference between rates of dementia when directly comparing older anticoagulants like warfarin with newer types, such as clopidogrel
  • people who had anticoagulant prescriptions 80% of the time were 48% less likely to get dementia than people who never had anticoagulant prescriptions (HR 0.52, 95% CI 0.5 to 0.55)
  • there was no association between anticoagulants and falls or flu

Anticoagulant use slightly increased the risk of diabetes and COPD, but as this association was in the opposite direction from that for dementia, the researchers remained confident in their results.

They also found that people prescribed anticoagulants were likely to be younger and healthier.

Apart from not taking anticoagulants, the factors most closely linked to chances of getting dementia were older age, Parkinson’s disease and alcohol abuse.

How did the researchers interpret the results?

The researchers said their results “strongly suggest that oral anticoagulation treatment protects against dementia in atrial fibrillation” and that “early initiation of anticoagulant treatment in patients with AF could be of value” to prevent dementia.

Conclusion

If you’ve been diagnosed with AF and prescribed anticoagulant treatments such as warfarin or clopidogrel, we already know they protect you against having a stroke. This study suggests they may also help protect you against dementia.

Cutting the risk of dementia for people who have a raised risk from AF would be an exciting step forward.

Unfortunately, we can’t tell from this study whether the protection against dementia was down to the anticoagulants because of the possible effect of unmeasured confounding factors.

Usually, we’d want to see a randomised controlled trial (RCT) to follow this study to find out if anticoagulant drugs really do have that effect.

But because people with AF are usually prescribed anticoagulants to reduce their risk of stroke, it wouldn’t be ethical to do an RCT, as it would leave people unprotected against stroke when a known preventative treatment is available.

Because of the difficulties of carrying out a proper trial, we’ll need to see more studies of the kind done here, in different populations, to see whether the results hold true.

It would be useful if future studies have clearer information about which confounding factors are being taken into account.

There are a few things we don’t know from this study.

  • The researchers were unable to differentiate between types of AF. Some people have just 1 episode of AF that doesn’t return or goes away with treatment, while others have persistent AF that happens all the time. The type of AF may affect both dementia risk and whether you’re prescribed anticoagulants.
  • We also don’t know which types of dementia people were diagnosed with. AF may be more strongly linked to vascular dementia than Alzheimer’s disease. But we don’t know for sure which type of dementia might be helped by taking anticoagulants.

You can reduce your risk of vascular dementia by avoiding conditions such as type 2 diabetes and high blood pressure, which can be triggered by smoking and obesity.

When it comes to dementia prevention, it’s often the case that what’s good for the heart is also good for the brain.


Published by the NHS on 25/10/17

Protection from stroke: How the internet can help 1.3 million UK Atrial Fibrillation patients

 Health  Comments Off on Protection from stroke: How the internet can help 1.3 million UK Atrial Fibrillation patients
Feb 032017
 

Atrial Fibrillation (also ‘AF’ or ‘AFib’) is a serious health condition that, if untreated, can have severe consequences. In the UK alone, 1.3 million are diagnosed with AF. Every 18 minutes a UK citizen suffers an AF-related stroke. Battling AF and its life-changing consequences is not only a task for medical professionals: patient behaviour greatly influences the risks associated with AF. Our infographic on Atrial Fibrillation in the UK summarises what patients need to know, what apps they can use, and what sites they should turn to for more information.

Click for full-size image

Choosing the right treatment for an AF patient is up to the cardiologist or GP. However, patients themselves can do a lot to manage their risk. This of course assumes informed patients with access to the right set of tools. To give an overview of AF as well as helpful tools and sites, we sat down together with Anticoagulation Europe and designed an infographic on Atrial Fibrillation in the UK: What is AF? How wide-spread is AF in the UK? What can you do as a patient to mitigate the risk of stroke? And what are apps for Atrial Fibrillation patients and sites building a sound understanding of the disease?

What is atrial fibrillation and why is it dangerous?

Atrial Fibrillation describes episodes of irregular heartbeat. As a consequence, the heart may not empty completely and dangerous blood clots can form. If a clot breaks loose it can travel from the heart to the brain, where it can cause a stroke. People with Atrial Fibrillation have a 5 times higher risk of having a stroke. In the UK alone each year 30,000 patients suffer from an AF-related stroke.

The causes of atrial fibrillation are not fully understood. UK data shows that men are more often affected by AF than women and that the risk increases with age. There are also a couple of conditions that often go along with or precede AF, such as Hypertension, Angina Pectoris or Diabetes. Atrial Fibrillation should be taken seriously. The good news: When discovered early, the right treatment can control your heart rate and lower your risk of stroke significantly.

I have Atrial Fibrillation. What can I do?

AF is a serious health condition and your doctor will guide you through diagnosis and treatment decisions. Regular doctor visits are important to monitor your treatment and your symptoms, such as shortness of breath, tiredness and dizzyness. However, also when you are on your own, there is a lot you can do to ensure treatment success and safeguard yourself:

Never miss a dose

With AF, you typically receive different kinds of medication: Heart rate control drugs manage your irregular heartbeat. Anticoagulants such as Warfarin, Xarelto, Eliquis or Pradaxa prevent clots from forming. So while you might feel an immediate benefit from taking your heart rate control drugs, regular intake of your anticoagulant is key for preventing stroke. The MyTherapy app (available for iOS and Android) has been clinically tested for supporting you in safely taking medications, be it Warfarin or one of the newer NOACs (‘Novel Oral Anticoagulant, e.g. Xarelto (Rivaroxaban), Eliquis (Apixaban) or Pradaxa (Dabigatran)). MyTherapy reminds you to take your meds on time. It also supports you in monitoring your measurements, such as your heart rate and weight. The built-in health report summarises your medications, measurements and symptoms so you and your doctor can oversee your health progress.

Stay fit

Exercising is a great way to improve your quality of life. Even with Atrial Fibrillation you can do moderate physical activities to keep a healthy weight and to reduce your heart rate. Apps like the ‘7 Minute Workout’ can help you finding the right exercise and staying motivated. Before you start, please consult your doctor what you can and what you cannot do. Also, make sure to slowly ramp up your level of exercise and to always watch your pulse and symptoms.

Minimise risk factors

High blood pressure, poor diet or smoking are proven risk factors for stroke. Take action and protect yourself from a stroke. Apps like ‘Lifesum’ and ‘Smoke Free’ can help you set up and reach your individual health goals.

Buildling a sound understanding of your disease is a pre-requisite for taking informed decisions regarding (un-)healthy behaviour. If you are based in the UK and need additional information about atrial fibrillation and stroke, also check out:

  • NHS Choices
  • Anticoagulation Europe
  • British Heart Foundation
  • Stroke Association
  • Thrombosis UK
  • AF Association

Article from MyTherapy on 17th January 2017

 

Doctors told to stop aspirin for heart condition

 Medical, News  Comments Off on Doctors told to stop aspirin for heart condition
Jun 152014
 

The following article appeared in The Times on 9th June 2014 –

Doctors have been told to stop prescribing aspirin for a common heart condition that raises the risk of stroke.

An estimated 300,000 patients with atrial fibrillation (AF) could be affected by the new guidelines issued by the National Institute for Health and Care Excellence (Nice).

Previously it was thought that aspirin could help to lower the risk of blood clots in AF, which causes an irregular and often unusually fast heartbeat. Continue reading »