The Voice in the Ear -- Burt's Blog
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April 2005 Archives:
11»  MRI and Stents
12»  Angioplasty vs. Surgery -- the SYNTAX Trial
27»  Carotid Stenting -- the BEACH Trial

April 27, 2005

BEACH at the Jazz
Breaking news about new therapies from the 14th Annual Peripheral Angioplasty and All That Jazz meeting in New Orleans, namely the BEACH trial, or the Boston Scientific EPI: A Carotid Stenting Trial for High-Risk Surgical Patients. (Does anyone think we may need more letters in our alphabet to accomodate these clinical trials?)

A revolution in the treatment of vascular disease has been happening and in the past six months there have been several big developments in the treatment of stroke. Angioplasty and stenting, usually thought of as a treatment for heart disease, is now being used throughout the body and last year, the FDA approved the first device for use in the carotids. There had been much talk in earlier days that carotid stenting was not as good as its surgical counterpart, called cartoid endartarectomy (CEA). However, the SAPPHIRE Trial, published in NEJM in October, not only showed the two treatments similar in outcomes, but in the patients studied, who were at high risk for surgery, there was almost 40% lower risk of death, stroke or heart attack with stents (20.1% for surgery; 12.2% with stent).

Today, the one-year BEACH trial data were presented by Dr. Christopher White of the Ochsner Clinic in New Orleans and these major complications for high-risk patients are now at 9.1% -- this was with Boston Scientific's WALLSTENT and FilterWire system, not yet approved for use in the U.S. (the only carotid stent currently approved is Guidant's AccuLink -- and that was just approved last August).

I'll be discussing the implications of this new technology, and its meaning for patients, in an upcoming report on carotid stenting. Also in an interview, to be posted later today, with Dr. White.

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April 12, 2005

The SYNTAX of the "Big Q"
Today Boston Scientific launched the SYNTAX clinical trial, to assess the current state-of-the-art comparison between surgery and catheter-based intervention. Recent clinical trials (discussed here) have focused on competing devices, Taxus vs. Cypher, Endeavor vs. bare metal stents, and so forth. But SYNTAX is going for the "big question".

Since its beginnings almost three decades ago, the "big question" for interventional cardiology (and interventional or "endovascular" therapy in general) has been whether or not it is durable enough to replace standard "open" surgical procedures. A wish of Andreas Gruentzig (inventor of coronary angioplasty) was to see a randomized trial comparing angioplasty (in his time that meant POBA, or Plain Old Balloon Angioplasty) to CABG, or Coronary Artery Bypass Grafting. Many cardiac surgeons scoffed at his technique and thought at most it would apply to 5% of patients.

Such a trial never occurred in his lifetime, but several have been concluded since (BARI, EAST, etc.) and the general findings are that for many patients there is little difference in the outcomes between PCI (Percutaneous Coronary Intervention) and CABG, so the less-invasive angioplasty seems the winner (about a third of PCI patients have needed a repeat procedure, but this no longer may be the case). PCI is also indicated if you are not a candidate for surgery, due to age or other health problems, or if you factor in some of the central nervous system function disturbance reported with bypass surgery, or if you like lying on a table in a cool room, listening to whatever CD the cath lab is playing that morning, while a cardiologist threads devices into your coronary arteries -- then angioplasty is best -- especially because it takes about an hour or so, usually only an overnight in hospital and a short recovery at home -- no zipper scar, etc.

These same studies showed, however, that for the most complex patients, diabetics or those with left main or significant multivessel disease, bypass surgery was the way to go because the PCI results were just not as "durable" -- there was too high a rate of revascularization or complications.

Enter the drug-eluting stent, called a revolution by some, and many of the less-than-perfect outcomes of PCI have been waved away -- recent studies with both currently approved DES (Cypher and Taxus) have shown great efficacy across the board in diabetic patients, and the Taxus V study showed great advances over bare metal stents in patients with multivessel, small vessel and wide vessel disease (implications for successful treatment of the left main, a wide vessel). Conditions that previously had been considered extremely high chance for restenosis, and therefore not worth doing, are now in play.

So with today's SYNTAX trial, current angioplasty/stenting (not the technology from 5 or 10 years ago) will be going head-to-head, okay...heart-to-heart with bypass surgery. Some doctors have been signaling a sea-change. Recently, Gregg W. Stone of Columbia University Medical Center in New York told Angioplasty.Org that:

"...for general referral, most patients now, we think well over 90% with coronary artery disease can be managed with angioplasty and implantation of a stent like the Taxus stent."

Now a randomized clinical trial of over 4,000 patients is going to test that hypothesis. If the outcomes for patients with advanced and complex disease show PCI/angioplasty with drug-eluting stents (a procedure involving a small puncture and an hour or so of time with an awake patient) is comparable to open surgery (which involves opening the chest, several hours of surgery under general anesthesia and a considerable recovery time) then, as Dr. Marie-Claude Morice (who announced the first SYNTAX patient) stated:

"The results of this study may profoundly change the practice of medicine."

You may call this "hype". But check out this quote, regarding surgery:

"This last part...namely a tacit acknowledgement of the insufficiency of surgery. It is like an armed savage who attempts to get that by force which a civilized man would get by stratagem."

Says who? Says John Hunter, considered the founder of Scientific Surgery, as he wrote over two hundred years ago in The True Principles of Surgery (1777). More on the stratagem to follow.

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April 11, 2005

MRI & Stents
There have been questions for years whether it is safe to perform Magnetic Resonance Imaging (MRI) on patients who have been stented (MRI safety was one of the earliest queries to Angioplasty.Org's discussion forum). The concern has been whether the magnetic field produced would move a metal stent that had been implanted in a vessel. The recommendations have been to wait a month or two. However, last week the FDA said that it was okay to conduct an MRI immediately post-procedure, if the stent was Boston Scientific's Taxus Paclitaxel-Eluting Stent, that is -- the first time a stent has been approved for immediate MRI -- important for a couple reasons.

First, there has always been increased concern about MRI and drug-eluting stents (DES) in particular, since the concept of DES is to slow down or reduce the growth of the endothelial layer over the metal stent and thus reduce the chance of restenosis or reclogging of the vessel -- but not so much as to prevent a thin layer of endothelial cells from covering the stent's surface, which embeds the artificial structure in the arterial wall. The question's been, does this increase the stent's "movability", for a time anyway.

The second point is that, while some cardiologists believe there isn't a problem and have been sending recently-stented patients to MRI for a while now (see comments by Dr. Thomas Gerber of the Mayo Clinic on members only last week's ruling should relieve any physician/patient anxiety, at least where the Taxus is concerned. Johnson & Johnson's Cypher DES has not gotten an approval for immediate MRI yet (although they are working on it) and they recommend an eight week wait post-stenting with the Cypher.

And again, my mantra -- developments in this field change so rapidly -- even the American Heart Association's web site still recommends against an MRI for at least four weeks after stent implantation, without a cardiologist's approval -- which is still a lot better than some major heart web sites that have just "discovered" that drug-eluting stents "may reduce restenosis".

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