John Mandrola, MD


May 05, 2016

Dr Paul Friedman, of the Mayo Clinic, uttered the best quote from the first day of the Heart Rhythm Society (HRS) 2016 Scientific Sessions. I heard it as I was walking out of a session. His words stopped me in my tracks.

"We have to be careful about trading one disorder for another," said the chair of a session on left atrial appendage closure.

His comment defines modern-day cardiology and electrophysiology. It captures the inelegance of so much of what we do, especially, when we ablate atrial fibrillation.

Whichever analogy you like, like two sides of a coin or parallax, the effect whereby something appears differently depending on the position of the lens, medical intervention brings both good and bad. Doctors and patients must know that.

Two AF-ablation–related abstracts at the featured poster session on Wednesday evening at the HRS meeting illustrate this.

One study[1]shines a favorable light on AF ablation. (Always start with the positive.)

Using a novel web-based automated follow-up system, the group at Cleveland Clinic, led by Ruth Madden, showed that patients feel better after ablation. That sounds simple and hardly new, but feeling better is the ultimate patient-centered outcome.

One good thing about the cold gray city of Cleveland is its proximity to Carnegie Mellon computer scientists, who delivered a beautifully designed web-based survey system for this study. Patients scheduled for AF ablation filled out a quality-of-life survey before the ablation and then were automatically asked to complete another 6 months and a year after the procedure. More than two out of three patients reported a decrease in AF symptom severity.

I like this abstract because patients didn't know their rhythm; they just knew they felt better. We know stroke risk and mortality in patients with AF depend on risk factors, such as age, diabetes, and hypertension, so to me, it matters little what the loop recorder says. AF on an event recorder is a mere surrogate. Quality of life is the outcome. The more we understand AF, the more that becomes clear.

Then there is another vantage point of AF ablation. It's a far less favorable image.

Medical doctors call them "SCIs," which stand for subclinical or silent cerebral infarction, or, if said with clarity, damaged areas of the brain because debris from the ablation traveled north to the brain and obstructed arteries in the brain.

A group from the Kyoto University in Japan presented[2] a sobering poster in which they did brain MRI scans before and after AF ablation in 498 patients. They found that one in three patients had evidence of subclinical infarction after the procedure.

One in three.

When the researchers compared the group of patients who had SCI against those who did not, they found both procedural and patient characteristics associated with lesions. Patients in the SCI group were more likely to have hypertension, higher CHADS2 score, larger left atrium, lower appendage velocity, and lower mean activated clotting times (ACT) during the procedure, although average ACTs were above 300 seconds. Notable for the minimalists out there, deflectable sheath use was more common in the SCI group.

On the actual poster, they showed pictures of two postprocedural brain scans. These were healthy patients who now had bright white spots on their brains.

To be fair to the language, the S in SCI is "silent," meaning the patient doesn't have obvious stroke symptoms. And sometimes these lesions disappear over time, but not always.[3] That's no small issue, given the increased risk of dementia and decline in cognitive function seen in elderly people with "silent" brain infarcts.[4]

I don't know about you, but AF becomes a smaller problem when the cost of ablation is trading better AF-related quality of life for one of those nasty white spots on a healthy brain. You can believe more aggressive [5]anticoagulation measures during the procedure will reduce the likelihood of this problem, but until there are big studies, like this one, that idea remains an optimistic belief.

Some experts say we aren't offering ablation of AF to enough patients, or we aren't intervening early enough.

I don't agree.

I think doctors (and patients) would do well to keep Dr Friedman's wise words in mind whenever we intervene. Perhaps those words could be put in a frame and posted in patient exam rooms adjacent to the sponsored "patient-education" pamphlets.



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