Monday, December 26, 2016

Dementia risk greater for AF patients with use of blood-thinning drugs

A new study reviewing medical data from 6,000 patients reports that individuals with atrial fibrillation who take anticoagulants are at higher risk of dementia than patients who take the blood-thinning drugs for other reasons.

Researchers have linked warfarin to increased dementia risk, particularly for patients with AF.

Atrial fibrillation (AF) is the most common irregular heartbeat condition. The incidence rate in the population of adults aged 65 and older is 10 percent, as reported by the Atrial Fibrillation Association (AFA). AF is not life-threatening in most cases, but it is known to be a leading cause of stroke.
Researchers from the Intermountain Medical Center Heart Institute in Salt Lake City, UT, compared the medical notes of patients who regularly took anticoagulants. They found that dementia cases were higher among AF patients.
The team presented their work at the American Heart Association Scientific Sessions 2016, held in New Orleans, LA.
Anticoagulant therapy is used to thin the blood of AF patients. The most commonly used anticoagulant is warfarin.
AF patients are prone to developing blood clots because their irregular heartbeat prevents the blood from being pumped through the chambers of the heart efficiently. This can lead of pooling of the blood and subsequent formation of blood clots.
Blood clots can travel to the brain and cause stroke. The AFA report that 3 million people worldwide are affected by AF-related stroke each year.

Dementia occurs more often in AF patients

Dementia is a broad term for a number of diseases that affect the brain and cause progressive intellectual decline. Alzheimer's disease is the most common form of dementia, but there are many others.
According to the National Institutes of Health, there are approximately 5 million individuals in the United States who have Alzheimer's disease. Dementia is now the leading the cause of death in England and Wales, as reported by the United Kingdom Office for National Statistics.
Age is thought to be the main risk factor for dementia. The number of people living with dementia is expected to increase, as life expectancy is getting longer.
Patients with AF have previously been reported to have a higher risk of developing all types of dementia.

Greater dementia risk for warfarin users with AF

In a retrospective study of medical notes, the team found that patients with AF who took warfarin were two to three times more likely to have dementia than those without AF who took warfarin.
The authors conclude that taking warfarin is associated with an increased risk of dementia in all patients, but more so in AF patients.
Lead author Dr. Jared Bunch, director of electrophysiology at the Intermountain Medical Center Heart Institute in Salt Lake City, explains:
"Atrial fibrillation patients are at higher risk of developing all forms of dementia compared to patients without atrial fibrillation."
"Warfarin is used to lower risk of stroke in patients with atrial fibrillation, but when the blood levels of the drug are erratic it contributes to the dementia risk," he adds. "This dementia risk is observed in people with and without atrial fibrillation that are exposed to long-term warfarin treatment."

Study limitations

In the study, the authors discuss the limitations of their work. They explain that a retrospective study such as this makes use of commonly used medical codes in patient notes in a database to assign patients to different groups, such as those who take warfarin and those with AF or other conditions.
Although this type of study can use the medical records of thousands of individuals, it is designed to look at how different conditions relate to each other, but not at cause and effect.
They suggest designing a prospective study, which recruits patients and follows them over many years. This type of study can specifically examine the mechanism by which warfarin therapy may cause dementia and how this is different in AF patients.
"Further research is needed to identify the many complex mechanisms that link atrial fibrillation to dementia. We are initiating a series of new studies that are aimed to understand what treatments may reduce the risk of developing dementia in atrial fibrillation patients," concludes Dr. Bunch.
Read about a study that suggests loneliness may be an early sign of Alzheimer's.

Written by Yella Hewings-Martin

Symptoms

Dementia symptoms vary depending on the cause, but common signs and symptoms include:

Cognitive changes

Memory loss, which is usually noticed by a spouse or someone else
Difficulty communicating or finding words
Difficulty reasoning or problem-solving
Difficulty handling complex tasks
Difficulty with planning and organizing
Difficulty with coordination and motor functions
Confusion and disorientation

Psychological changes

Personality changes
Depression
Anxiety
Inappropriate behavior
Paranoia
Agitation
Hallucinations

When to see a doctor

See a doctor if you or a loved one has memory problems or other dementia symptoms. Some treatable medical conditions can cause dementia symptoms, so it's important to determine the underlying cause.

Causes

Dementia involves damage of nerve cells in the brain, which can occur in several areas of the brain. Dementia affects people differently, depending on the area of the brain affected.
Dementias are often grouped by what they have in common, such as the part of the brain that's affected or whether they worsen over time (progressive dementias). Some dementias, such as those caused by a reaction to medications or vitamin deficiencies, might improve with treatment.

Progressive dementias

Types of dementias that progress and aren't reversible include:

Alzheimer's disease. In people age 65 and older, Alzheimer's disease is the most common cause of dementia.
Although the cause of Alzheimer's disease isn't known, plaques and tangles are often found in the brains of people with Alzheimer's. Plaques are clumps of a protein called beta-amyloid, and tangles are fibrous tangles made up of tau protein.
Certain genetic factors might make it more likely that people will develop Alzheimer's.
Vascular dementia. This second most common type of dementia occurs as a result of damage to the vessels that supply blood to your brain. Blood vessel problems can be caused by stroke or other blood vessel conditions.
Lewy body dementia. Lewy bodies are abnormal clumps of protein that have been found in the brains of people with Lewy body dementia, Alzheimer's disease and Parkinson's disease. This is one of the more common types of progressive dementia.
Frontotemporal dementia. This is a group of diseases characterized by the breakdown (degeneration) of nerve cells in the frontal and temporal lobes of the brain, the areas generally associated with personality, behavior and language.
As with other dementias, the cause isn't known.
Mixed dementia. Autopsy studies of the brains of people 80 and older who had dementia indicate that many had a combination of Alzheimer's disease, vascular dementia and Lewy body dementia. Studies are ongoing to determine how having mixed dementia affects symptoms and treatments.

Dementia-like conditions that can be reversed

Some causes of dementia or dementia-like symptoms can be reversed with treatment. They include:

Infections and immune disorders. Dementia-like symptoms can result from fever or other side effects of your body's attempt to fight off an infection. Conditions such as multiple sclerosis that result from the body's immune system attacking nerve cells also can cause dementia.
Metabolic problems and endocrine abnormalities. People with thyroid problems, low blood sugar (hypoglycemia), too little or too much sodium or calcium, or an impaired ability to absorb vitamin B-12 can develop dementia-like symptoms or other personality changes.
Nutritional deficiencies. Not drinking enough liquids (dehydration); not getting enough thiamin (vitamin B-1), which is common in people with chronic alcoholism; and not getting enough vitamins B-6 and B-12 in your diet can cause dementia-like symptoms.
Reactions to medications. A reaction to a medication or an interaction of several medications can cause dementia-like symptoms.
Subdural hematomas. Bleeding between the surface of the brain and the covering over the brain, which is common in the elderly after a fall, can cause symptoms similar to dementia.
Poisoning. Exposure to heavy metals, such as lead, and other poisons, such as pesticides, as well as alcohol abuse or recreational drug use can lead to symptoms of dementia. Symptoms might resolve with treatment.
Brain tumors. Rarely, dementia can result from damage caused by a brain tumor.
Anoxia. This condition, also called hypoxia, occurs when organ tissues aren't getting enough oxygen. Anoxia can occur due to severe asthma, heart attack, carbon monoxide poisoning or other causes.
Normal-pressure hydrocephalus. This condition, which is caused by enlarged ventricles in the brain, can cause walking problems, urinary difficulty and memory loss.

Risk factors

Many factors can eventually lead to dementia. Some factors, such as age, can't be changed. Others can be addressed to reduce your risk.

Risk factors that can't be changed

Age. The risk rises as you age, especially after age 65. However, dementia isn't a normal part of aging, and dementia can occur in younger people.
Family history. Having a family history of dementia puts you at greater risk of developing the condition. However, many people with a family history never develop symptoms, and many people without a family history do. Tests to determine whether you have certain genetic mutations are available.
Down syndrome. By middle age, many people with Down syndrome develop early-onset Alzheimer's disease.
Mild cognitive impairment. This involves difficulties with memory but without loss of daily function. It puts people at higher risk of dementia.

Risk factors you can change

You might be able to control the following risk factors of dementia.

Heavy alcohol use. If you drink large amounts of alcohol, you might have a higher risk of dementia. Some studies, however, have shown that moderate amounts of alcohol might have a protective effect.
Cardiovascular risk factors. These include high blood pressure (hypertension), high cholesterol, buildup of fats in your artery walls (atherosclerosis) and obesity.
Depression. Although not yet well-understood, late-life depression might indicate the development of dementia.
Diabetes. If you have diabetes, you might have an increased risk of dementia, especially if it's poorly controlled.
Smoking. Smoking might increase your risk of developing dementia and blood vessel (vascular) diseases.
Sleep apnea. People who snore and have episodes where they frequently stop breathing while asleep may have reversible memory loss.

Complications

Dementia can affect many body systems and, therefore, the ability to function. Dementia can lead to:

Inadequate nutrition. Many people with dementia eventually reduce or stop their intake of nutrients. Ultimately, they may be unable to chew and swallow.
Pneumonia. Difficulty swallowing increases the risk of choking or aspirating food into the lungs, which can block breathing and cause pneumonia.
Inability to perform self-care tasks. As dementia progresses, it can interfere with bathing, dressing, brushing hair or teeth, using the toilet independently and taking medications accurately.
Personal safety challenges. Some day-to-day situations can present safety issues for people with dementia, including driving, cooking and walking alone.
Death. Late-stage dementia results in coma and death, often from infection.

Health