Better Health: Smart Health Commentary Better Health (TM): smart health commentary

Article Comments

Study Looks Into New Afib Treatment: It’s Not All Good News

The news wires for atrial fibrillation were abuzz this last week. The vigor and speed with which health news travels is striking.

Since 2.6 million Americans live with AF, my guess is that many are looking at the release of the Medtronic-sponsored TTOP-AF trial with anticipation. Here is a link to the press release. The trial purported to show benefits of Medtronic’s novel phased RF ablation system in treating persistent AF.

The study was small and released at a relatively small symposium in Venice, Italy. The TTOP-AF trial randomized 210 patients with persistent AF (including flutter) to either ablation with Medtronic’s ablation system or conventional therapy with drugs and cardioversions.

They found, not surprisingly, that AF ablation reduced AF burden. AF ablation significantly reduced AF burden in 55.8% percent of patients versus only 26% of those treated with conventional medical treatment. Editorial comment: That kind of data is pretty typical.

The problem with the study comes in the safety arm: 21 of 138 patients in the ablation arm “experienced one or more protocol-defined adverse events.” This included four patients with manifest stroke, seven with PV stenosis and one death. Post-ablation MRI scans were not reported so we don’t know how many patients in each arm had non-symptomatic MRI brain lesions. (See below.)

PVAC catheter

The still-investigational Medtronic ablation system used in the trial is much different than what is used in the real world. Their PVAC catheter is a novel circular catheter that can deliver simultaneous encircling lesion around the pulmonary veins. The notion is sweet because at the moment we have to deliver single lesions in a labor-intensive point-by-point manner. Placing a catheter just outside the orifice of the vein and making one burn would be great.

The problem with the technology rests in its physics. Energy delivery via the long electrodes on the PVAC catheter (which are not irrigated with saline, like our present catheter), increases the risk of clots forming in the left atrium. It has to do with varying temperatures at varying contact points along the left atrial wall-electrode(s) interface.

In considering the value of this novel technology, it’s important to call your attention to this recent paper in the Journal of the American College of Cardiology. Here, the highly-respected AF researchers from Bordeaux showed an alarmingly high rate of embolic lesions (clot-related mini-strokes) in patients ablated with the very same PVAC catheter. In this trial, 37.5 % of patients ablated with the PVAC catheter had discrete lesions on MRI brain scans after the procedure.

I’ve said it before, and it bears repeating:

One of the major tenets of treating AF is to avoid making the treatment worse than the disease.

I’m afraid this technology, in its current form, will not prove safe enough. The risk of stroke is just too high. I’m sure Medtronic is working on making a safer catheter. Hopefully they will succeed.

*This blog post was originally published at Dr John M*

You may also like these posts

    None Found

Read comments »

Comments are closed.

Return to article »

Latest Interviews

IDEA Labs: Medical Students Take The Lead In Healthcare Innovation

It’s no secret that doctors are disappointed with the way that the U.S. healthcare system is evolving. Most feel helpless about improving their work conditions or solving technical problems in patient care. Fortunately one young medical student was undeterred by the mountain of disappointment carried by his senior clinician mentors…

Read more »

How To Be A Successful Patient: Young Doctors Offer Some Advice

I am proud to be a part of the American Resident Project an initiative that promotes the writing of medical students residents and new physicians as they explore ideas for transforming American health care delivery. I recently had the opportunity to interview three of the writing fellows about how to…

Read more »

See all interviews »

Latest Cartoon

See all cartoons »

Latest Book Reviews

Book Review: Is Empathy Learned By Faking It Till It’s Real?

I m often asked to do book reviews on my blog and I rarely agree to them. This is because it takes me a long time to read a book and then if I don t enjoy it I figure the author would rather me remain silent than publish my…

Read more »

The Spirit Of The Place: Samuel Shem’s New Book May Depress You

When I was in medical school I read Samuel Shem s House Of God as a right of passage. At the time I found it to be a cynical yet eerily accurate portrayal of the underbelly of academic medicine. I gained comfort from its gallows humor and it made me…

Read more »

Eat To Save Your Life: Another Half-True Diet Book

I am hesitant to review diet books because they are so often a tangled mess of fact and fiction. Teasing out their truth from falsehood is about as exhausting as delousing a long-haired elementary school student. However after being approached by the authors’ PR agency with the promise of a…

Read more »

See all book reviews »

Commented - Most Popular Articles