Gender differences in the treatment of Atrial Fib

I was recently asked a seemingly simple question about differences in how women with atrial fibrillation (AF) are treated.

The questioner was referring to this large AF-ablation study published a year ago in the Heart Rhythm Journal. Researchers at St David’s Hospital in Austin, TX reported striking differences in the outcomes and complications of more than 3200 women that underwent AF-Ablation at 5 different centers.

Here’s a highlight of the differences outlined in this study:

• Women underwent AF ablation 5 times less often than men.
• AF ablation was less successful in women.
• Women were older than men at the time of AF ablation.
• Women had failed more drugs than men before referral for ablation.
• Women had later stage AF at the time they were referred for ablation.
• Women were more likely to have atypical firing-sites (outside the pulmonary veins) for AF.
• Women had more bleeding complications after ablation.

These data are consistent with other well known facts about heart disease in women.

• Women with AF are at greater risk for stroke than men. In fact, the association is so strong, European investigators give female gender a full point in their more detailed CHADS2-VASc score for predicting stroke in AF. (A concise summary on CHADS2-VASc is here, on TheHeart.org.)
• Women are more susceptible to AF-drugs, especially those that increase the time it takes the heart to relax (QT-prolonging drugs). In other words, the electrical properties of the heart cell often vary by gender.
• The most common form of SVT (Supraventricular Tachycardia), AV Nodal Reentry (AVNRT) occurs more often in women.
• Women are under-referred for other innovative cardiac technologies, like defibrillators, bypass surgery and cardiac catheterization.

So what was that simple question?

What’s the explanation for these striking treatment differences in women with AF?

The researchers from Austin offer only speculation. They suggested that women may present later in the course of their disease because they are more stoic about their symptoms. Or, women may have fewer AF-ablations because they are less likely to agree to invasive therapy. They even cited child-care responsibilities as a possibility.

Famous author and WSJ columnist, Peggy Noonan, writing with Melanie True Hills, editor of the well known AF-website, StopAF.org weigh in with another possible explanation:

“I think today it’s more often an issue of differing communication styles between doctors and women patients…

Doctors are trained to listen for facts, but as women we may be “genetically programmed” to communicate with more emotion and feelings that give context and richness to our messages. That can create miscommunication as doctors may not hear or understand all of what we’re saying. I often hear a common refrain of “my doctor didn’t listen to me.” It may actually be a case of the doctor hearing the words, but not the whole message.”

I can’t say that I have any better explanations. I don’t think anyone knows for sure.

But I can say that I haven’t noticed similar patterns in my AF practice. (Neither did two other private practice AF-ablation colleagues that I asked before writing this post.) That doesn’t mean I don’t believe their data. I do. It appears to be clean, unbiased reporting of what they found.

In our real-world AF practice, however, it hasn’t been obvious that women are under-represented as ablation candidates. I also have not noticed that our ablation success rates are lower, or complication rates higher in women. And, I hear women with AF describe equal degrees of breathlessness, fatigue and quivering as men.

The caveat here, of course, is that real-world AF doctors do not have at their disposal an army of foundation-supported research associates. We have our reading of the literature, and our experiences with patients that we have ablated (or not ablated.)

As the treasure of ablating AF–relief of symptoms without medicine–gets spread to more patients, real world data from national registries, like SAFARI, will add greatly to our knowledge base. Since the 1990s, heart rhythm doctors often use the expression, learning while burning. Yes, in AF, catheter ablation continues to teach us about this amazingly complex disease. The learning is at a fever pitch at the moment.

For now, I would offer this practical advice to women with AF:

• Talk to your doctor clearly about your symptoms. Your AF doctor needs to know the degree to which AF symptoms disrupt your quality of life. Symptoms are one of the major factors that determine whether AF ablation is recommended.
• Women should know that AF ablation works best when done early in the natural history of the disease. They should urge to be referred to an AF doctor earlier in the course of AF: when AF is still occurring intermittently, rather than permanently, for example.
• Women might remind their AF-doctor to look carefully for sites of triggering outside the PV areas. In other words, if AF is triggered from Kansas, an electric fence around the coast lines won’t do any good. (We do this as a matter of routine in all patients.)
• Women should seek out an enlightened, experienced AF-doctor who listens to you, and isn’t upset if you bring this kind of ‘e-info’ to the visit.

As a learner, I am interested in the opinions of others. Please feel free to offer them in the comments section.

JMM