AF ablation Atrial fibrillation

More notes from the first day of the Boston AF symposium

 The second half of the day was fast paced and full of information. Folks, these are rough notes. Hope they help…Again my random thoughts are in italics. 

Dr Eric Prystowsky led off the with the best clinical papers of 2011: He is a great speaker and hit upon a bunch of important topics. 

The good trials: 

Rocket AF: rivaroxaban was shown non-inferior to warfarin for stroke prevention in AF. Bleeding risk was equal to warfarin. A more impressive trial was Aristotle, which showed the yet-to-be-approved blood-thinner apixaban clearly superior to warfarin in AF. 

Then the trials he labeled, ‘too bad’:

“Preventative medicine needs to be started early,” this he agrees. The problem is that many of the “upstream” treatments–that is, treatments that treat AF’s associated diseases, like high blood pressure–have not panned out as clearly protective in AF. He mentioned the irbersartan trial–no preventative effects were seen with the use of this typical high blood pressure drug. 

I wonder whether the problem with these kinds of prevention trials is that they aren’t starting treatment early enough. I wonder if we encouraged people to begin healthy living before trouble starts–as in before middle-age. The same message was sounded this morning during the basic science lectures. 

Of course, the ugliest trial of the year involved…you guessed it…dronedarone. The PALLAS trial clearly showed that dronedarone worsened outcomes in permanent AF. This is not new news. (See next lecture, by Dr Kowey.) 

Dr P then progressed to the AF ablation trials. His theme was that AF ablation can’t seem to break the 80% success threshold. He mentioned some possible explanations. A Japanese group suggested we don’t wait long enough during the procedure after isolating the veins. They showed that PV reconnections may occur after the usual thirty minute waiting period. In pointing out the importance of selecting patients for AF ablation, he mentioned MRI studies suggesting that LA fibrosis predicts ablation failure. The consensus was that we need to figure out the best candidates for ablation. And there are probably different approaches for different patients. (In the afternoon sessions, where live and recorded cases were shown, there were many varying approaches to ablating AF. Think…no consensus.) 

Silent brain lesions after ablation have become a matter of concern. I have written about the problems with the PVAC catheter previously, but Dr P pointed out that silent brain lesions still occur with saline-irrigated catheters and cryo-balloons, albeit it at very low rates. The good news here was that most of these small and non-symptom-causing lesions go away, but a small percentage persist. These are important concerns. 

His next study surprised me. He showed us results from a small study on the use of acupuncture in maintaing regular rhythm after a cardioversion. Though the cited trial (from his journal, JCE) had small numbers, acupuncture looked pretty good–almost as good as amiodarone. That’s pretty nifty. 

His final three studies involved the notion that chronic kidney disease predicts AF risk; asymptomatic AF episodes may be important in unexplained stroke; and AF clearly has a genetic basis. How else could one explain the data that African-Americans have much less AF?, he asks.  I’ll give myself a pat on the back for mentioning this observation in this morning’s notes. 

Next talk…

Dr Peter Kowey spoke about the use of AF drugs in clinical practice. He focused his entire talk on dronedarone (Multaq.)

After giving a detailed historical sketch of the drug’s development, he left us with two interesting conclusions: one is that he believes dronedarone should remain on the market, but its use should be restricted to cardiologists and electrophysiologists, who can monitor patients closely. It is important that patients be monitored to make sure that they stay the same, specifically, if they develop heart failure or permanent AF, dronedarone should be stopped. He also mentioned a trial called HARMONY, which will test the combination of ranolazine and dronedarone. He was enthusiastic about this combination because pre-clinical trials indicate that the combination might be a “block-buster.” 

Hmm. My feelings about dronedarone have not changed. 

Next up…

Difficult cases in real-world AF management: An expert panel discussed cases. (Only one of the experts was under the age of 50.)

There were 4 cases presented. Important and controversial topics about the use of AF drugs, blood-thinning medicines and the role of ablation were discussed in detail.

The most notable case involved a middle-aged runner with atrial flutter. The consensus was telling: long-term endurance exercise definitely increases AF risk and these patients often respond best to ablation, rather than drugs. Hans Kottkamp, offered a funny comment, “many patients in Switzerland run up hills like crazy…We have lots of AF in athletes.” Dr Camm showed a number of interesting studies confirming the endurance exercise-AF link. 


Dr Dhanunjaya Lakkireddy, from Kansas, showed his ACC abstract on the AF-soothing aspects of yoga. He’s showed this study before. You guessed it: patients with PAF who participated in regular yoga classes had fewer episodes of AF, lower BP and better scores on quality of life questionnaires. 

I just love it–I mean really love the idea that yoga has benefits in a disease so entwined with inflammation. Hear-hear!

The final four hours of the afternoon involved satellite case presentations. There were cases from Spain, Hamburg, Bordeaux, Michigan and two from Italy. 

I’m biased because of my friends in Hamburg, but I believe Prof Karl-Heinz-Kuck stole the show. He presented completely new and novel data about a new technology called contact force. Basically, a force sensor in the tip of the ablation catheter indicates the force of contact. The Hamburg data (Efficas 1 and 2) tell two important stories: one is that sites of ablation with low contact force correlate with future gaps in the PV isolation lines. The second, and completely novel data involved what he called the concept of continuous lesions. That is, lesions encircling the veins should be made without jumping around–as coming back to a site is less effective, perhaps because the swelling from the previous burns may lower the burn’s durability.

Interestingly, Dr Kuck’s idea that “the first lesion has to be the perfect lesion represents an old idea that was espoused by Dr Sonny Jackman in the 1990s for WPW ablation. 


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