News outlets reported this week on a new JAMA study showing that having a heart defibrillator implanted by an electrophysiologist produces fewer complications for patients than if a doctor outside that specialty does the procedure.

I asked Martin C. Burke, DO, to comment on the article and the background that makes this important for patients and physicians, and he graciously agreed. Here is Dr. Burke’s post:

The new JAMA article regarding physician certification for implantable cardioverter defibrillator (ICD) implantation and patient outcome is interesting to me as a practicing electrophysiologist, or electrician of the heart, as well as a trainer of the next generation of electrophysiologists.

In 2004, the medical society that represents the heart electricians called the Heart Rhythm Society or HRS published criteria for certification that allowed non-electrophysiologists to implant ICDs without going through the rigors of a fellowship in clinical cardiac electrophysiology.  The electrophysiology fellowship training pathway provides a one- or two-year intense exposure to the management of heart rhythm disorders as well as training in the complex interventional procedures such as the ICD implantations and more complex cardiac resynchronization ICD implantations mentioned in the JAMA article.  The HRS certification criteria for non electrophysiologists has been used by hospitals and third-party payors to allow non-electrophysiology board eligible or certified physicians to get credentialed by hospitals to implant and get paid for such implants.

At the time of the publication of the 2004 paper, the membership of  the heart rhythm society was mystified as to why our own society would sanction such a document and essentially ‘throw under the bus’ our training pathway in heart rhythm disorders that we take quite seriously.  We as the heart rhythm society and I as a trainer of electrophysiologists have spent the last 20 plus years advancing the science and application of such devices in a methodical and expert way.  So, the logical deduction is that this policy has been the agenda of the device manufacturing companies who felt that there weren’t enough cardiac electrophysiologists to meet the needs of the public indicated for such devices.  

This is an incendiary topic as the financial implications at stake are large for all parties. Consequently there has been great controversy within the HRS membership, and it has recently bubbled into a call for our medical societies to sever all relationship with industry, a typically American over-reaction. Industry working with clinician scientists is of huge value to society at large as long as it is disclosed and managed ethically.  Of more concern to me are cases where study authors do not disclose potential conflicts of interest - a practice that remains distressingly common.

Still, patients should be assured that in science, the true path eventually becomes evident and now patients can move forward with expert device implantation and management with the best-trained physicians in the world to do so: the clinical cardiac electrophysiologists.  

You’d rather not live without any organ, but some are easier than others to replace with technology. Kidney fails? Get dialysis. Diabetes saps your pancreas? Take insulin. Heart gives out suddenly? Try a left ventricular assist device.

Credit: HepaLife

But the liver poses a special problem. Its biochemistry is so complex that no one understands all the functions it serves, or the details of how it works. We do know it’s essential for blood clotting and for removing a wide range of toxins from the bloodstream. Acute liver failure can lead to death within 48 hours. Yet even the liver’s well-defined functions are difficult to mimic completely. Then there are the thousands of proteins the liver produces, many of which have poorly understood roles in the body.

All of that makes it hard for artificial livers to do much more than help patients survive a few more hours while they wait for a donor organ. Even the term “artificial liver” is a bit misleading, because most of the devices rely on liver cells of some kind. Duplicating their function from scratch is just too difficult. (Imagine if heart assist devices had to use actual heart muscle cells.)

As this Forbes piece observes, several companies have gone out of business trying to make artificial livers. One of the rare success stories that the story cites is a University of Chicago patient, Amy Petrovic, who nine years ago survived on a synthetic liver for a few days - long enough for her condition to improve so she could survive a liver transplant operation. 

Attempts to make reliable devices keep coming - one company this week announced plans for a new Phase III trial of an artificial liver system, and a separate trial started last month. But stories like Petrovic’s also underscore the immensity of this challenge, and the limits of medical knowledge. Many hurdles in medicine are purely technological in nature. In this case, researchers don’t know exactly where the technological intervention should start, because they don’t fully grasp the underlying biology.