Atrial fibrillation: Catheter treatment may reduce dementia risk

  • Researchers investigated the effects of treating atrial fibrillation via catheter ablation and medication on dementia risk.
  • They found that treatment via catheter ablation reduced dementia risk more than medication alone.
  • Further studies are needed to confirm the link and understand what underlies it.

Atrial fibrillation (Afib) is a heart condition characterized by irregular beating in the upper chambers of the heart that reduces blood flow to the lower chambers. Afib can cause discomfort in patients and increase stroke risk by five times.

In 2019, AFib was mentioned on 183,321 death certificates in the United States. Estimates state that the condition will affect 12.1 million people in the U.S. by 2030.

Studies show that AFib is a risk factor for cognitive decline and dementia. Research also shows that when patients with dementia and cognitive impairment have AFib, they experience worse cognitive decline than those without.

Understanding whether treating those with Afib reduces dementia risk could improve patient outcomes.

Recently, researchers compared how catheter-based and pharmaceutical treatments for Afib affect dementia risk.

They found that the catheter-based treatment for Afib was correlated with better cognitive ability than medication alone.

“I have seen several patients with longstanding persistent atrial fibrillation who have had cognitive impairment, reduced ability to swallow, and slower motor function even despite negative brain imaging studies. Based on this, I do not find [the results surprising],” Dr. Vicken Zeitjian, a cardiologist board-certified in echocardiography and nuclear cardiology, based in San Antonio, Texas, who was not involved in the study, told Medical News Today.

“These findings provide further evidence that atrial fibrillation management by catheter ablation is superior to medical management only,” he added.

The study will be presented at the American Academy of Neurology’s 75th Annual Meeting.

Catheter ablation vs. medication

For the study, the researcher included 887 participants with Afib who were an average age of 75 years old. Among the participants, 193, or 21.8%, received catheter ablation prior to enrolment, while the remaining patients received medication for Afib alone.

Catheter ablation involves passing a tube into the heart that, using radiofrequency, destroys small areas of heart tissue that may cause an abnormal heartbeat.

The researchers assessed participants’ cognitive function at baseline and after one and two years. Cognitive scores were out of 30, with 23 and under indicating cognitive impairment.

In the end, the researchers found that those who received catheter ablation had an average cognitive score of 25, whereas those without the procedure had an average score of 23.

After adjusting for factors like heart disease, renal disease, and sleep apnea, the researchers found that those who underwent catheter ablation were 36% less likely to develop cognitive impairment than those treated with medication alone.

They noted, however, that there were no significant differences in heart attack events between those who underwent catheter ablation or medication alone.

They further found that the use of warfarin and other anticoagulants did not significantly affect cognitive decline.

Catheter ablation and dementia risk 

MNT asked Dr. Aaron Ritter, director of the Memory & Cognitive Disorders Program at Hoag Hospital in Newport Beach, California, who was not involved in the study, how catheter ablation may reduce dementia risk. He noted that while the study does not explain how, there may be several reasons.

“For me, it may be that ablation is a more definitive or long-lasting therapy while medication management requires adherence to a daily medication regimen—sometimes twice a day. In people with memory problems, we have to question if the compliance issue is relevant to the outcome,” he said.

“Furthermore, we may also hypothesize that ablation may be more a successful treatment for atrial fibrillation, and as a result, individuals may have fewer blood clots or better consistent delivery of blood and oxygen to the brain because the atrial fibrillation is treated better with ablation,” he explained.

“Hopefully future studies will also include measure of blood flow that will allow us to make better conclusions about the reason ablation proved more successful in this study,” he noted.

Limitations 

Dr. Fanny Elahi, physician-scientist and Assistant professor of neurology, neuroscience, and pathology, molecular, and cellular-based medicine and Icahn School of Medicine at Mount Sinai, who was also not involved in the study, told MNT:

“While these data are exciting, more research is needed to understand the relationship between catheter ablation (CA) and dementia. The study appears to be observational rather than a randomized trial with cognition as a co-primary outcome, which makes me wonder whether the study is confounded by the baseline health of those who receive CA.”

“The primary limitation is that there were no measures of cerebral blood flow to accompany the cognitive tests. The other limitation is that the authors analyzed a relatively limited assessment of cognition- a 30-point cognitive test,” Dr. Ritter added.

“Typically studies use more extensive evaluations of cognition to measure cognitive decline so making firm conclusions from a relatively short battery of testing limits understanding of what specific aspects of cognition— memory, language, executive function—were benefited by ablation,” he noted.

Implications 

Dr. Rina Shah, a cardiologist at Staten Island University Hospital, who was not involved in the study, told MNT:

“It is important to consider that AFib prevalence increases with age as does dementia. However, AFib can cause multiple other medical problems and can lead to hemodynamic deterioration as well as cardiomyopathies if rates are difficult to control. By treating patients with catheter ablation sooner, we can help prevent or delay the deleterious effects of AFib.”

Dr. Elahi, meanwhile, said the study highlights the importance of brain-body connections.

“[If] we want to improve brain health, we need to treat the entire person. If there is a true effect here, implementing molecular and imaging biomarkers could further delineate the impact,” she said.

“I am a big proponent of understanding the biological effects of such interventions because to combat brain degeneration and cognitive decline, we likely need multiple shots on goal. Identifying why something works gives us the opportunity to improve the intervention with synergistic approaches,” she concluded.

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