Researchers Found A Surprising Brain Link To This Heart Medication
Managing atrial fibrillation (AFib), a common heart rhythm problem that makes the heart beat irregularly, can already mean making a lot of decisions about medication.
That can get even more complicated when Alzheimer's is also in the picture. One of the big questions is whether to take a blood thinner to lower the risk of stroke.
Now, research suggests the specific blood thinner someone takes may be linked to more than just their heart health.
In a recent study of more than 7,000 people with Alzheimer's and AFib, researchers looked at whether different medications were associated with differences in memory and thinking over time.
About the study
Researchers looked at 7,308 people who had Alzheimer's and AFib. They used Sweden's national dementia registry to track the group from 2007 to 2020.
The researchers compared people taking three different approaches: no blood thinner, warfarin (an older blood thinner), or newer blood thinners called NOACs, including medications such as apixaban and rivaroxaban.
AFib matters here because it can make blood clots more likely to form in the heart.
If a clot travels to the brain, it can cause a stroke. Even smaller strokes that go unnoticed may affect memory and thinking over time. Blood thinners help lower the chance of those clots forming.
People taking NOACs had slower cognitive decline
Over five years, people taking NOACs had slightly slower declines in memory and thinking than people taking warfarin or no blood thinner. The warfarin and no-blood-thinner groups declined at about the same rate.
There were some differences in other health outcomes, too. Compared with people who weren't taking a blood thinner, those taking NOACs had fewer strokes, dangerous blood clots, deaths, and bone fractures. They also did not have a higher rate of major bleeding.
Warfarin was linked to fewer strokes and deaths as well, but people taking it had more serious bleeding than those who weren't taking a blood thinner.
When the researchers compared the two medications directly, people taking NOACs had fewer strokes and major bleeding events than those taking warfarin.
Why the heart and brain may be connected
The link between AFib and brain health isn't completely out of left field. When the heart beats irregularly, blood can sit in the heart longer than usual, which makes clots more likely to form.
If one of those clots reaches the brain, it can cause a stroke that affects brain function. Other heart events have been tied to faster memory decline years down the road, too.
So, one possible explanation is that preventing more clots may also help protect the brain. Researchers are looking at another possibility, too.
Some of the proteins involved in Alzheimer's may also affect the body's clotting process, potentially increasing inflammation and making it harder for the brain to clear harmful proteins.
That part is still being studied, though.
And there's a big reason not to jump to conclusions about the new findings. This was an observational study, meaning researchers could spot a connection but couldn't show that NOACs actually caused slower cognitive decline.
There may have been other differences between the groups that influenced the results.
What to know if you take a blood thinner
If you have AFib, your doctor may recommend a blood thinner to help prevent a stroke.
Warfarin is an older option that requires regular blood tests and can be affected by vitamin K and other medications. NOACs are newer and usually don't require as much routine monitoring.
The findings don't mean that everyone taking warfarin should switch. The researchers specifically said that the possible brain benefit shouldn't drive medication decisions because it hasn't been proven yet.
If you have AFib and Alzheimer's, you can ask your doctor whether your current blood thinner is still the best choice for you.
They can look at your chances of having a stroke or serious bleeding, your kidney health, and any other medications you take. It's also a good moment to ask about other ways to take early action against cognitive decline.
The takeaway
Among people with Alzheimer's and AFib, those taking NOACs had slightly slower declines in memory and thinking, along with fewer strokes and major bleeding events than those taking warfarin.
The findings add to what we know about the heart-brain connection, but they don't show that these medications can treat or slow Alzheimer's.
