Dr J Mandrola - Left Atrial Appendage Closure should stop now

[Bagrat]

medscape.com/viewarticle/87...

I know some of you belong to Medscape and for those who aren't it is free to join.

Interesting article

[BobD Volunteer]

Strange maybe but I never join such things on internet. What is the gist of the article please Bagrat. I know that I have mentioned on more than one occasion that some doctors believe that the LAA DOES have a purpose and that removing or occluding it is not a good idea. .

[Bagrat]

" Conclusion. The evidence is clear and consistent: occlusion of the left atrial appendage with Watchman fails to protect against ischemic events. This is not surprising if you think about stroke as a systemic disease. Current thinking on AF and embolic stroke must include more than just closure of the left atrial appendage. In patients with AF, vascular risk factors, nonatrial stroke mechanisms, and abnormal atrial substrate surely play a causative role for stroke. I encourage you to read this comprehensive review from the journal Stroke in which the authors call for a new model of thinking about stroke and AF.[7]

On the matter of anticoagulation-ineligible patients, some doctors believe appendage occlusion could be helpful. The answer is we don't know because these patients were not included in the clinical trials. I doubt it would be effective in this cohort. Appendage occlusion clearly does not reduce ischemic events. Proponents might point to hemorrhagic-stroke reduction with the device, but that's simply due to not using anticoagulation. And even if you posit an absolute risk reduction of 1% to 2% with the device, that's likely balanced by a 1% to 2% complication rate of implantation. And this reasoning assumes perfect closure of the appendage, which is far from reality. A contemporary series of Watchman implants found significant leaks in more 20% of cases (46/219).[8]"

Some of you may remember that I strongly believe interpretation of research should be left to the experts. Dr Mandrela points out that first trials research was done for Watchman the makers of the device. He also discusses the Prevail trial in some detail. He first raised this issue over a year ago.

[Gilldy in reply to Bagrat]

Thanks for this - i joined and read it - certainly reads differently to most info available ion the internet. Very interesting!

[PeterWh in reply to Bagrat]

I do remember and I forgot to say this previously.

I don't fully agree with you because often a well informed non expert can shed a different light or angle on things and a better result or interpretation results.

When I first saw my EP he told me to read up on all the publications on the main AFA website. I also read other ones. Then when I saw him the third time after my DCCV had only lasted 24 hours I gave him a summary as I saw it and asked questions. One of my interpretation and thoughts hadn't occurred to him before probably because I wasn't an expert and hence saw something differently.

I'll give you an example. I was one of four or five specialists in a preparation meeting for a court hearing where there were a couple of barristers and about 6 lawyers in the room. The senior barrister was leading and talked for 10 to 15 minutes or so on one aspect on a group of 9 contractural clauses. At the end of this I piped up and said I disagreed with a number of things regarding the interpretation and importantly the application of those clauses in the contractural world so to speak. I gave my reasons and the alternative interpretations. At the end of this the leading barrister said Peter I have just had to rip up the first four pages of my opening speech but I don't mind because your interpretation is much more sound and your views are much better than us legal experts. Obviously he put my points into "legal speak".

[PeterWh in reply to PeterWh]

I should have said that with the EP in fact I had a couple of things slightly wrong because there was insufficient information there but he had the missing information and hence a more appropriate and correct conclusion.

[Bagrat in reply to PeterWh]

That's a very good point. I would be more forthcoming about research in my own specialty because I would feel more confident that I had been "at the coal face" so to speak. In a sense as people who live with AF we ARE at the coal face also. Thanks Wendy b

[ILowe]

There is an interesting area of research in the Social Sciences, concerning the role of the expert + role of non expert. I am not an expert in that literature, but do give an hour or so of lecture time to my linguistics students. It merits a separate thread. Some research has shown that the educated layman can be as right at the same rate as the experts. I view it as a complementary relationship.

As the layman, I am focussed, very focussed, just on me. Therefore, whenever something new happens I have to get up to speed. An expert knows the broader field already. They are also much more likely to know the mechanisms, the technicalities. They are likely to understand the technical literature better, though there is anecdotal evidence that even experts do NOT always understand. What they are better at is allowing their background to carry their gaps, whereas a layman gets stuck.

Practically, I have found it best to approach experts in a, 'I am the ignorant one, but I sure would like you to explain things to me. I see it this way, but what is wrong' etc. In short, asking questions. Any true expert can explain themselves to semi-experts.

The idealistic spirit of science breeds humility. It is evidence and logic that counts, not status. I really admire and trust experts who are willing and humble enough to discuss with me. One consultant actually encouraged me to bring articles to him. Most of the time he swiftly put me right -- and that was a good learning experience. Sometimes he thanked me for bringing something to his attention he had missed. As an expert he gained in a better grasp of what the patient thought, therefore was better placed to interact with me because he knew where I was.

PeterWH, the specialist who listened to you. Bravo to him. I trust him.

Much of science is resistant to thinking out of the box, and there can be penalties for doing so. That means the informed patient, this forum etc become even more important.

[PeterWh in reply to ILowe]

At the end of the day the best results.rtc come about by teamwork (but not necessary committees!!!!!!).

[BobD Volunteer]

Ex = has been. Spurt=drip under pressure.

There is often acceptance of norm or "we have always done it that way" in any industry or business. I remember many years ago having an interesting conversation with a designer at a famous race engine manufacturer over what I considered to be overly high valve spring pressures only to be told that they had always used them. About three months later a new version of the engine appeared which gave 40 more horsepower and 500 more revs and guess what. No I never got any credit for it but at least he thought my argument sound enough to at least investigate.

Coming back to the original publication one of the reasons I was given all those years ago to continue anticoagulation after successful ablation is that AF and also ablation changes the internal surface of the atrium (substrate mentioned) in such a way as to make eddy currents and possible clots more likely. Analogy may be calcium deposits inside water pipes causing noise. There has for some time I feel been too much focus on the LAA as a source of clots to the exclusion of all else.

All that said we must remember that this is all still very new science with little LONG term result data so changing views are inevitable.

[MarkS]

It's an excellent article by John Mandrola. It shows up the distortion of the statistics that can happen with industry sponsored trials. There must be compulsory publication of all trials and all data so it can be open to review by others.

[Judydiane]

The reality of "industry sponsored trials" is the source of my anxiety about taking any of the new anti coagulants for the rest of my life. Has anyone been taking them for a number of years??? If so, have you had any problems? My cardiologist offered the assurance that the drug (Pradaxa.....since then switched to xarelto) had been tested for many years in Europe. I accepted what he said because of the stroke risk. But i'm still quite uncomfortable. Thoughts?

[MarkS in reply to Judydiane]

I think you're right to be concerned. Industry sponsored trials will always try to get a positive result - after all they don't want to have sunk perhaps £100's of millions in development to fall at the last hurdle. So trials can be designed to produce the "right" result. So with NOACs you would want the comparison to poorly controlled warfarin. Compliance with taking NOACs every day is a problem so you ensure there is a lot of follow up to make sure the drugs are being taken, etc, etc.

There were a lot of problems with the Rely trial for dabigatran (pradaxa), see:

ncbi.nlm.nih.gov/pubmed/224...

Personally I stick with warfarin and I test my INR weekly and make sure it's in range. Then it's better than any NOAC.