Most doctors would prescribe blood-thinning drugs, also known as anticoagulants, to people recently diagnosed with atrial fibrillation (AF), an irregular heartbeat. These drugs are known for their ability to prevent blood clots and, subsequently, reduce the risk of stroke. But now, after digging deeper, scientists from the Karolinska Institute reveal that the drugs can also lower the risk of dementia in AF patients.
Published in the European Heart Journal, the new study is the largest to investigate the connection between anticoagulant drugs and dementia in people diagnosed with AF. More than 2.7 million Americans are currently living with AF, which poses a risk for cognitive decline and dementia in addition to stroke.
“In order to preserve what you´ve got, you should take care to use anticoagulants if you are diagnosed with AF, as they have been proved to protect against stroke and, which this study indicates, also appear to protect against dementia,” explained Dr. Leif Friberg from the Karolinska Institute.
The retroactive study involved nearly half a million people with AF, some taking anticoagulant drugs to treat their condition and some not. Those taking anticoagulant drugs for the purpose of blood clot prevention also had a 29 percent lower risk of developing dementia, compared to people not taking the drugs. Even more, the protective effect against dementia grew over time, and the sooner oral anticoagulants were given to AF patients after their diagnosis, the greater the protective effect against dementia.
"Doctors should not tell their patients to stop using oral anticoagulants without a really good reason,” Friberg recommended. “Explain to your patients how these drugs work and why they should use them.”
Nearly half a million Americans develop dementia every year. Experts studying AF and the risk of dementia say that AF can lead to brain injury from blood clots blocking blood flow in the brain, what many refer to as a “silent stroke.” Along with a condition called “white matter disease,” where tissue containing nerve fibers that connect to other parts of the brain fades away, AF is a serious factor that contributes to dementia.
Researchers from the study theorize that the anticoagulants reduce the risk of dementia by preventing things like silent stroke and white matter disease. Ultimately, Friberg says, the most important message for AF patients is to take and continue taking anticoagulant drugs.
“If you know that AF eats away your brain at a slow but steady pace and that you can prevent it by staying on treatment, I think most AF patients would find this a very strong argument for continuing treatment.”