Are women with AF being under-treated with ablation?

This post is an introduction to commentary I made recently over at theHeart.org on Medscape. Gender features in the discussion, but there are lessons for men and women with AF.

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A large study from a group of Stanford researchers made three big observations on AF ablation:

• Women, compared with men, presented for first AF ablation at an older age and with more risk factors (higher CHADSVASC score.)
• At 30 days after the ablation, women compared with men, suffered from more complications.
• At one year after the ablation, women compared with men, had more re-hospitalizations but fewer cardioversions and repeat AF ablation.

The first two findings confirmed results of previous studies. For whatever reason, it’s not well-understood, women who come for first ablation often have more advanced atrial disease. It’s also well established in cardiology, not only EP, that women have higher rates of complications with procedures.

The third finding was provocative. It tempts one to think women are getting cheated out of repeat ablation and cardioversions.

Here are the Stanford authors (italics mine):

“Our findings, in context, may be indicative of potential barriers to optimal or sustained rhythm-control strategies in women. . . . These data call for greater examination of barriers and facilitators to sustain rhythm-control strategies in women.”

A reader could infer two benevolent biases in these words: women are getting stiffed out of more cardioversions and AF ablation, and that’s bad because rhythm-control strategies are good.

I would propose a contrarian view. Women who undergo first AF ablation present with more associated diseases, older age, and more advanced forms of AF. They also experience more procedural complications. It’s possible, therefore, that more rhythm control (with ablation) could worsen a gender gap in outcomes.

In other words, women might do even worse with more ablation.

The reason I propose this contrarian view gets back to the guts of the AF ablation procedure. Pulmonary vein isolation, the agreed upon foundation of AF ablation, was first described as a treatment of focal atrial tachycardia coming from within the pulmonary vein muscle bundles. (A rare form of AF.) A focal treatment for a focal disease.

Now, doctors have extended the use of PVI to people with diffuse atrial disease, metabolic risk factors (obesity, high blood pressure, diabetes), and inflammation. This can be a wrong target problem.

A 2010 study from Dr. Natale’s group showed that a higher burden of structural disease in the atria may be the reason women have more non-pulmonary vein triggers. Non-PV triggers are bad because it’s very hard to find and ablate them.

Here is the take-home:

The Stanford findings allows doctors to make opposite explanations: the easy and conventional one is that women are under treated with redo ablation; the other view is that maybe women should not get more ablation after failed ablation.

The reason we could have such opposite views is our lack of understanding of the disease AF.

Recent evidence on AF suggests that AF is often the heart’s way of manifesting “tension” or disequilibrium. The tension may be too much inflammation (pericardial fat or recent infection/surgery); or maybe the tension is too much stretch (obesity, sleep apnea, hypertension, excess endurance exercise); or maybe the tension is too much neural disruption (stress, lack of sleep, alcohol). Sometimes it’s multiple combinations of these.

The AF ablation procedure can do only one thing well: isolate the pulmonary veins. This electric fence around parts of the left atria does little to treat most of the above conditions that ail the atria.

The title and link of my referenced article is here:

Less AF Ablation in Women: Gender Bias or Appropriate Care?

JMM