John D Day, MD

AF Symposium 2015

Leaving Patients in A-Fib Doubles Risk of Dementia—The Case for Catheter Ablation

By Steve S. Ryan, PhD

Dr. John Day of the Intermountain Heart Institute, Murray, UT gave a presentation on the “Elimination of AF as a Strategy for Prevention of Stroke and Cognitive Impairment.”

Case of 64-year-old Male In Persistent A-Fib Not Thinking Clearly

Dr. Day began by presenting the case of a 64-year-old male family friend who went into persistent A-Fib in 2013. He was on flecainide, aspirin and Lisinopril (an ACE inhibitor for his high blood pressure). He exercised daily. His BMI (Body Mass Index) was 26 (20% overweight but not obese). His “thinking (was) not as clear.”

Dr. Day gave the following choices as the next step in treating him:

1. Try a different anti-arrhythmic drug?
2. Start warfarin?
3. Start a novel anticoagulant?
4. AF ablation?
5. None of the above/don’t know

In my opinion, the most important red flag is the statement that he wasn’t thinking as clearly. Because he has been in persistent A-Fib, blood flow to his brain and other organs has been reduced by 15%-30%. This can lead to dementia.

A different antiarrhythmic drug probably wouldn’t “cure” him and get him permanently back into sinus rhythm. And while he was trying different antiarrhythmic drugs, his dementia “not thinking clearly” might worsen.

Current guidelines and the fact that he exercises every day would probably indicate that warfarin and the NOACs wouldn’t be justified. They could cause unnecessary bleeding risk which might cause micro-bleeds in the brain and more dementia. His daily exercise improves blood flow in the LAA where most clots originate and would significantly lower the risk of developing an LAA A-Fib clot.

The best chance to return him to sinus rhythm [thereby restoring normal blood flow to his brain] was probably an A-Fib ablation.

During his presentation Dr. Day described what was done to this patient. He first had an A-Fib ablation which was unsuccessful. Three months later he had a successful ablation which restored him to sinus rhythm. He has lost weight (BMI 23), no longer has high blood pressure, is no longer taking antiarrhythmic drugs and is only on aspirin.

It’s not surprising that he would need two ablations to be restored to sinus rhythm. He was in persistent A-Fib for over a year which is more difficult to cure by just one ablation.

A-Fib Doubles Silent Stroke Risk and is Associated with Dementia

Dr. Day pointed out that A-Fib doubles the risk of having a silent stroke. ¹ Many studies have shown that A-Fib is independently associated with dementia.² “AF is associated with a higher risk for cognitive impairment and dementia, with or without a history of clinical stroke.” ³

In one study of 11,723 patients, those with Cardiac Ectopy were 4 ½ times more at risk of developing dementia. ⁴

Rate Control Therapy Questioned

Dr. Day pointed out that the AFFIRM study (which suggested there was no difference between rate and rhythm control therapy) was only for less than five years. There is no long-term safety data on leaving people in A-Fib on rate control drugs.

In the AFFIRM study, most of the rhythm-control patients took antiarrhythmic drugs (AADs) to try to stay in sinus. Very few had catheter ablations. But AADs are known to have many toxicities which caused their own set of health problems and negatively influenced the results.

It makes no sense to leave people in A-Fib while only controlling their heart rate. A-Fib is a progressive disease that remodels and worsens the heart over time. Leaving people in A-Fib can be a death sentence. (See Medicines or ‘Drug Therapies’ for Treatment of A-Fib, Approach 1: Rate Control.

Mechanisms of A-Fib Dementia

Dr. Day described four possible mechanisms that may lead to A-Fib dementia:

1. Macro/Micro Thromboembolism (strokes). (He showed MRI slides of resulting cerebral ischemia [swelling] from strokes). Patients who stayed in a therapeutic INR range were much less likely to develop dementia.

2. Cerebral Bleeds. Dr. Day questioned whether all women with A-Fib should be anticoagulation candidates. The guidelines give women one point simply for being a woman. He showed MRI slides of cerebral microbleeds from warfarin and studies of warfarin’s intracranial bleed risk ⁵ He also showed how over-anticoagulation increases the risk of dementia. (AHA Annual Scientific Sessions 2014)

(Added January 26, 2016: A recent study found evidence of microbleeds in 99% of subjects aged 65 or older, and that increasing the imaging strength increased the number of detectable microbleeds. Microbleeds have been suggested to be predictive of hemorrhagic stroke.)⁶)

Added February 19, 2018: A Swedish retrospective registry study found that anticoagulant treatment was associated with a 29% reduced risk of dementia, that the risk of dementia is higher in A-Fib patients without oral anticoagulation treatment. But it should be noted that “the absolute risk reduction is quite small.”⁷ (In the small population that received the newer anticoagulants, the risk of dementia was slightly less than with warfarin.) Dr. Friberg didn’t speculate on how or why anticoagulants decreased the risk of dementia.

Some speculate that anticoagulants, while preventing macro-clots (strokes), also prevent or reduce micro-clots and smaller ischemic events which damage the brain over time. However, the risk of microbleeds wasn’t studied, with the possibility that anticoagulation may be detrimental in this regard. “A supertherapeutic INR in those prescribed an antiplatelet agent in addition to warfarin has been associated with an increased dementia risk, supporting the possibility that microbleeds may play a role in dementia pathogenesis in AF.”⁸

This study obviously contradicts much of the research in this article and may change current treatment practices.

3. Weakened Cerebral Blood Flow. Dr. Day showed slides of how different areas of the brain in A-Fib receive both less blood flow and irregular pulsivity (sustained power of blood flow).

4. Systemic Inflammation.

Preventing Dementia—The Case for A-Fib Ablation

Current drugs, even statins, don’t work or have mixed results in preventing dementia.

Dr. Day listed the often-described life-style strategies to prevent dementia: mental stimulation, exercise, maintain an ideal weight, plant based diet and fish, social interaction, rejuvenating sleep, stress reduction.

But he also included A-Fib elimination in this list. Patients who get a catheter ablation for A-Fib have long-term rates of dementia similar to people without A-Fib. This study included 37,908 patients followed for three years. ⁹

This result holds regardless of their CHADS2 score. ¹⁰

Not only are the long-term rates of dementia “similar”, but they are actually lower (0.4%) than for people without A-Fib (0.7%). A-Fib drug rates were significantly higher at 1.7%)

Danger of Silent Strokes with A-Fib Ablation?

Dr. Day discussed an earlier article which suggested that the silent stroke risk during or caused by an ablation ranged from 7%-38%. ¹¹

But at his facility which uses MRI to detect strokes and TIAs, they have never seen a silent CVA (Cerebral Vascular Accident)! He thinks this may be because they use irrigated tip catheters only, they maintain a therapeutic INR, their ACT (Activated Clotting Time) before the ablation is greater than 300 ¹² and their procedures are short.

Editor’s Comments:

Leaving People in A-Fib is Dangerous and Unacceptable: Perhaps at long last we have driven a stake through the AFFIRM-based notion that it’s fine to leave people in A-Fib, as long as their heart rate doesn’t go too high. Thanks to Dr. Day and many other researchers, we know that leaving people in A-Fib is dangerous and, among many other bad effects, can lead to dementia.

Dementia Prevented by A-Fib Ablation: For A-Fib patients the most important finding of Dr. Day’s research is that a catheter ablation prevents dementia!!! It’s not an absolute guarantee, but a catheter ablation for A-Fib reduces the risk of dementia to that of people without A-Fib. In fact, the risk rate is even less than for people without A-Fib.

Being Female Isn’t a Risk Factor for A-Fib Stroke: We have to admire Dr. Day’s courage to take on the medical establishment and the anticoagulant pharmaceutical industry. Dr. Day may be the first A-Fib leader to publicly question the current anticoagulant guidelines which give women one point on the stroke risk CHA2DS2-VASc scale just because of their gender. Many doctors have said this in a circumspect way. Dr. Eric Prystowsky in a presentation at last year’s AHS meeting thought that most doctors would agree with Dr. Day, “as long as there wasn’t a camera focused on them.” He gave the example of a 45-year-old woman in good health and a 45-year-old man with hypertension who according to current guidelines should both be given one point on the stroke risk CHA2DS2-VASc score.

As readers of A-Fib.com, you know that’s been my opinion since the original European guidelines came out. Women in their child-bearing years are much less at risk of stroke because of the blood-thinning effect of losing blood each month. And even after menopause women have less risk of stroke. But eventually they do have more strokes. But not because of an innate inferiority, but because women live longer than men. Stroke is age related.

For more, see The Denmark Study: Women in A-Fib Not at Greater Risk of Stroke Contrary to CHA2DS2-VASc Guidelines! See also the recent Israeli study Being Female Not a Risk Factor for Stroke.

Be advised that the original European guidelines were written by doctors with major conflicts of interest. These guidelines may be a not so very subtle form of gender bias.

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Last updated: Sunday, February 23, 2020

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