Anticoagulant drugs may protect against dementia as well as stroke in people with an irregular heartbeat, new research suggests.
A Swedish study found that patients being treated for atrial fibrillation were less likely to develop dementia if they were taking anticoagulants.
Their risk was reduced by up to 48% compared with others with the same condition who were not prescribed the drugs. The study, published in the European Heart Journal, found no difference in dementia prevention between the older blood-thinning drug warfarin and newer anticoagulants.
Researchers found that of 444,106 patients in Sweden who had atrial fibrillation, an abnormal heart condition that can provoke strokes, those taking drugs to prevent blood clots had a 29% lower risk of developing dementia. The risk further decreased as patients continued to take the medication.
The study is the largest ever on the link between anticoagulants and dementia in atrial fibrillation patients.
The strong link with dementia suggests blood thinners are responsible for lowering risk, but clinical trials would be needed to establish cause-and-effect, the scientists said. There is, however, a catch.
“Such studies cannot be done because of ethical reasons,” said lead author Leif Friberg, a researcher at the Karolinska Institute in Stockholm. “It is not possible to give placebo to atrial fibrillation patients and then wait for dementia or stroke to occur.”
Scientists had speculated that anticoagulants might stave off dementia because they prevent tiny clots that can cause unnoticed microscopic strokes, a major contributor to cognitive decline.
Researchers identified all patients in Sweden diagnosed with atrial fibrillation between 2006 and 2014. They then checked on what drugs had been prescribed, and followed the patients’ progress. When they first joined the study, 54% of patients were not taking oral anticoagulants such as warfarin or apixaban.
The researchers found that the strongest predictors for dementia were lack of oral anticoagulant treatment, ageing, Parkinson’s disease and alcohol abuse.
They also found that the sooner oral anticoagulant treatment was started after a diagnosis of atrial fibrillation, the greater the protective effect against dementia.
An alarmingly high percentage of patients stop taking their medication after a few years, Friberg added. “In the first year, approximately 15% stop taking the drugs, then approximately 10% each year [thereafter].”
I take warfarin daily to prevent blood clots from forming on my St. Jude, aortic heart valve, which might break away, travel to my brain and cause a stroke.
Now, this breakthrough study says these oral anticoagulants slash the risk of being struck down by dementia.Steve's Take: Breakthrough finding that #Alzheimers may be due to tiny blood clots in brain Click To Tweet
I’ve had several close calls that could have led to a quick exit. On the other hand, I witnessed what happened to my father after the onset of Parkinson’s. As the disease worsened and the years went by, dementia ensued, and we watched him gradually disappear before our eyes. After he mercifully passed, we all agreed a quick exit is by far the preferable method of departing this realm.
Dr. Friberg from the Karolinska Institute, who co-led the above study, said: “As a clinician I know there are AF patients who have a fatalistic view on stroke. Either it happens, or it does not. [But] few patients are fatalistic about dementia, which gradually makes you lose your mind.”
Not exactly subtle, but I admire his matter-of-fact choice of words.
Friberg added, “No brain can withstand a constant bombardment of microscopic clots in the long run. Patients probably want to hang on to as many of their little grey cells for as long as they can.”
The breakthrough finding has given fresh hope that a disease modifying therapy for the incurable condition of dementia is now in sight, says the UK’s Express.
James Pickett, head of research at Alzheimer’s Society, said: “We know that what is good for your heart is good for your head. Because of this, many research studies are examining the benefits of treating problems with the blood and heart to potentially prevent or slow down cognitive decline, including some funded by Alzheimer’s Society.”
Dr. Carol Routledge, director of research at Alzheimer’s Research UK, said: “Stroke is a major risk factor for vascular dementia. Not only do anticoagulants protect against stroke in people with an abnormal heart rhythm but this study also links them to a reduced risk of dementia.
Routledge added, “Dementia has a complex relationship with other health conditions and studies like this can help inform decisions around how those conditions are treated to bring most benefit to the individual. We desperately need to develop effective treatments that target the causes of dementia, and looking at the effects of existing drugs could radically accelerate the time it takes to find a life-changing treatment.”
“Warfarin can be a difficult drug to start,” said Dr. T. Jared Bunch (Intermountain Health Care, Salt Lake City, UT). “It takes routine blood monitoring, and there are frequent drug-to-drug and drug-to-food interactions that change the levels,” Bunch said.
What often ends up happening is that physicians and their patients opt for an “easier” route and start antiplatelet therapy with aspirin, but this is not the approach to take, Bunch noted.
“I think our study highlights important findings for clinicians,” said Bunch.
“Delays in warfarin use are extremely common in the healthcare system. Unfortunately, even more common is just general underuse of anticoagulants. Depending on the group you look at, anywhere from 30% to 50% of people who should be on blood thinners are not.”
“That said, it’s going to be tough to beat warfarin started immediately,” Bunch added. “Our dementia rates are almost zero if warfarin is started quickly.”
It’s important to understand that this astonishing study doesn’t recommend that everyone rush to their doctor to get on an oral anticoagulant. Such medicines are primarily indicated where there is an increased risk of stroke due to blood clot. And they do have the increased bleeding risk. Just happens that they also cut your risk of dementia by half.
Alzheimer’s, the most common form of dementia, is a disease known as the “long goodbye.”
For those who have seen loved ones start with forgetfulness, gradually lose their independence, become bed ridden and eventually mute, I say: if you’re on a blood thinner, continue with it. If you just started, don’t quit. If you know someone you care about who’s on a blood thinner or used to be, share this piece with them.
If I’m lucky to have any say in it, among the multitude of exit scenarios, I’m hopeful for the quick one. You know, the really big bus, or…
Alzheimer’s Association 2017 Quick Facts:
- Alzheimer’s disease is the 6th leading cause of death in the United States.
- More than 5 million Americans are living with Alzheimer’s.
- Every 66 seconds, someone in the United States develops Alzheimer’s disease.
- Since 2000, deaths from heart disease have decreased by 14% while deaths from Alzheimer’s disease have increased by 89%.
- In 2016 more than 15 million Americans provided an estimated 18.2 billion hours of unpaid care for those with Alzheimer’s or other dementias, valued at $230 billion.
- Alzheimer’s is the only cause of death among the top 10 in America that cannot be prevented, cured, or even slowed.
- Alzheimer’s disease kills more than breast cancer and prostate cancer combined.
- 1 in 3 seniors dies with Alzheimer’s or another dementia.