Wednesday, May 02, 2007

Defibrillator Complacency

It's been quite busy lately, making blog maintenance a bit tough. But I came across a good review article from the Journal of the American Medical Association (JAMA) that highlights the decision-making process that practitioners must negotiate when considering a defibrillator implantation on their patient with a reduced ejection fraction and well-compensated ischemic cardiomyopathy.

It's a very common scenario: an older gentleman, Mr. M, is 7 years out from his large anterior wall myocardial infarction (heart attack) who has been doing fairly well as a car salesman, but notes exertional fatigue. He wonders why he might need an ICD, even this late after his heart attack:
I’ve been talked to about putting a device in my chest that is supposed to regulate the heart. I’ve talked to a few different doctors on it, and I thought I had a grasp on the situation. But my understanding of it is that at the present time it's not a necessary thing. I’m 6 years removed from having my original procedure; I want to know why it's important to do it now. Right now, for me, right at this particular moment, there's no reason for me to do it. That's why I’m having such a hard problem as far as making a decision on it.
But the discussant does a good job explaining the rationale for recommending a defibrillator, even this late after a heart attack:
Mr M is beyond the early post-MI phase, but is well-represented by 2 of the previously cited trials. The control groups of the MUSTT and MADIT 2 trials enrolled patients an average of 3 and 7 years following MI, respectively. These trials included patients with a high incidence of CHF and a modest rate of -blocker and ACEI use and found that during a mean follow-up of 3 years, mortality rates were more than twice those documented in VALIANT. A substudy from MADIT 2 evaluated the influence of time post-MI on benefit derived from ICD implantation. In this analysis the reduction in mortality associated with ICD implantation persisted even in patients enrolled longer than 10 years following an MI. Therefore, current practice is to wait at least 6 weeks post-MI but not to limit how long after MI an ICD will be considered. In summary, Mr M can assume he continues to be at elevated risk for arrhythmia despite the 7 years that have passed since his MI, and that an ICD could reduce that risk.
I hear this resistance to implanting patients with ICD's late after myocardial infarction often. But our reluctance to advise patients about these devices might just cost someone their life.

This article does a great job reviewing the pro's and con's of defibrillator implantation and their benefits late after a prior heart attack. Unfortunately, it requires a prescription to view the entire text of the article, but I encourage doctors to review this piece if they care for patients that might be eligible candidates for this technology.



Margaret Polaneczky, MD (aka TBTAM) said...

What's your opinion on this t-wave alternan's thing? DOes it really triage who needs an implantable from those who don't?

DrWes said...


Some of my earlier thoughts about t-wave alternans testing can be found here.

Since that post, I met with the t-wave alternans guy to see if this might be good for our office. I learned about what makes a test "indeterminant" - things like PVC's, or poor electrode contact - and that it takes about 40-60 minutes to perform one of these, and the reimbursement for the professional fee (excluding the technical component) was about $100 from Medicare. If we subtract out the $75 for the patches - I figured I make (at best) $25 for my 40 minutes. Now, to add even more fun, the reimbursement for this test requires very specific coding guidelines be followed to assure payment (it is not intuitive). Soooo, needless to say, we punted.

Although there may be benefit in a small subset of patients, given the above shortcomings, it is hard for me to adopt this technology.

Anonymous said...

mr wes.,..i wont even use dr. because you should be ashamed of yourself...first of all average is 322.00 -75=250.00...but either way do you tell your patients you dont do twave test because there is no money i n it for you?....not because it doesnt work? have just proven to all your patients you are a DAngerous doctor to go to....

DrWes said...


Does not doing a test make me dangerous? There are many other ways to test patients at risk for sudden death.

To suggest that doctors should work for free is also flawed, is it not? Don't forget the cost of the technician to prep the patient, the receptionist and billing staff who struggle to get any reimbursement, and even the electricity bill to power the t-wave alternans machine, etc. Reimbursements must cover costs, whereever they are found. I would suggest that I am being honest here, not dangerous.

And one final comment regarding your numbers, are they based on a hospital-based reimbursement rate or an outpatient private-practice reimbursement rate? (There is considerable difference: hospital-based physicians who use the hospital's machine make much less, since they cannot bill the technical fee you have included in your reimbursement rate).

Hope this is explains my perspective-

"Mr." Wes, indeed.

Anonymous said...

"Does not doing this test make me dangerous" YES. How many recalled implants have you had to deal with? How many patients are walking around with the unneccesary ICDs? The 98% negative predictive value of this test far outways any explinantion that you could give to reason that you should not be utilizing this test. Not to mention the number of patients that you can't talk into the invasive Ep study, how many patients might consider an ICD if you had a NON_INVASIVE positive test that would help them take the next step to the invAsive test and possible ICD implantation. I'm disappointed in your position.

DrWes said...

Anony 5:23PM, if I had a financial stake in the company that made these devices, I'd be disappointed in my position, too.

But for the sake of argument, read this. I respect Anne Curtis - and I think she does a good job explaining the issues. While I respect your views, certainly you do not respect mine. So lets take this third party and read what she says:

The biggest issue (and what's so tough for physicians) is deciding what our tolerance is for any event beyond zero in these low-risk patients. I am confident that a negative result on T-wave alternans testing makes the likelihood of an event much lower. But if you take the likelihood of an event and you drop it down to a 99% assurance that nothing's going to happen, is that good enough? That still means there's a 1% chance that something is going to go wrong. The problem is that if you're in that 1%, you want to have a defibrillator, but then the other 99% are treated unnecessarily. So we may need to reach some consensus as to what level of risk we're willing to accept. Maybe an event risk of 1% to 2% over time fits into the acceptable range because that's about the risk of a complication with the ICD implantation procedure, but we haven't reached that consensus yet.

Are you, sir or madam, so confident in "98%" that you're willing to look a 45-year old father of four kids with an EF of 25% on diuretics, beta-blockers, and afterload reducing agents in the eye and tell him "it's OK, you really don't need a defibrillator based on a negative t-wave alternans test" and ignore other studies (MADIT-II, SCDHeFT) which suggest he might live longer with one? What if that guy was you?

What if you're wrong?

You'd be dead wrong, wouldn't you?

Look, I can fix inappropriate shocks if they happen. But I can't get a life back if I'm wrong.

Anonymous said...

wes,,,now its getting better...of course you are in bed with the lovely ann curtis..And for the record with me you have met your match..I have read every comment anne has made in her lifetime on icds, and i have expressed my opinion on her stance many times, which of course as a leader at HRS, comes from the same text book of greed over life, so its funny you would choose anne as your savior, but that wont work either wes,,,this time you put your foot in your mouth, and now you have sanctioned your earlier comments with more proof whats in your heart...DO YOU TELL YOUR PATIENTS YOUR POSTION BEFORE YOU CUT THEM OPEN?...dO YOU OFFER THEM TO PAY FOR THE TEST ITSELF BEFORE YOU IMPLANT THEM?...SINCE YOU ARE SO BRAZEN WITH YOUR HONESTY , I THINK YOU SHOULD CERTAINLY SHARE YOUR ATTITUDE WITH THEM..fUNNY THING IS , STILL, your only argument is money....Does giving them an mtwa test, whether negative or positive, whether you implant or not, endanger them?...Or could this test just be one more way of helping doctor and patient make a rational decision?,,why couldnt you give test and tell patient 99% of negative patients never need an icd...AND LET THEM wes, i guarantee 2.7% of your implant patients have experienced a problem with their icd, while it never saved their wes dont you think its a shame you ruined 17 out of the 18 implant patients lives because you needed to support your lifestyle? are just one more out of a group of many who continue to hang on to a failed system, which is getting run over, by the should be put out of business.,

Anonymous said...

one more thing wes, do explain why some doctors ARE buying the unit?...WHAT IS THEIR RATIONALE?...WOULDNt it be weird to have some doctors using and some not?...WHAT doctor would you send your dad to ,,,you or this guy at ucla?....more proof...not only does it work wes, but its the underlying cause of scd...

T-wave Alternans and Sudden Cardiac Death: How Are They Mechanistically Linked?
Biomathematics Seminar T-wave Alternans and Sudden Cardiac Death: How Are They Mechanistically Linked?

Zhilin Qu, Ph.D.

Department of Medicine (Cardiology)
David Geffen School of Medicine at UCLA

Thursday, May 3, 2007 4:00 PM (refreshments)
33-105 Center for the Health Sciences

ABSTRACT: Sudden cardiac death, mainly caused by ventricular fibrillation, is the leading cause of death in the industrialized countries. Antiarrhythmic drugs are not effective and some even increase mortality. While the implantable cardioverter defibrillator (ICD) is effective, but expensive and limited in availability worldwide. Therefore, it is important to develop effective antiarrhythmic drugs and/or tools to predict the population at risk who will truly benefit from ICD and drug therapies. Microvolt T-wave alternans has been shown clinically to be predictive for cardiac arrhythmia risk and is the only effective noninvasive method, yet the exactly mechanism remains unknown. In this seminar talk, I will show how mathematical modeling, computer simulation, and theoretical treatment by us and others, combining with experimental studies, have contributed toward revealing the mechanistic links between T-wave alternans and sudden cardiac death. Host: Dr. Tom Chou,

Anonymous said...

Speaking of a finacial stake, which companys ICD implant do you and Ann use. Should we Google search your names with consulting agreement for the answer.

DrWes said...


I guess it's not okay that look at this differently than you, is it?


Hence the blog...

"Or could this test just be one more way of helping doctor and patient make a rational decision?,,why couldnt you give test and tell patient 99% of negative patients never need an icd...AND LET THEM DECIDE"

All of my patients decide for themselves, and all have signed informed consent.

"you should be put out of business.,"

It is clear we're getting nowhere with this thread, but out of disclosure and "honesty," I'll leave your comments up. I'll let others decide who's "flawed" here.

Sayspine -

Please search - but let me help you - I use Medtronic and have speaking agreements with them. I use Guidant, and have a speaking agreement with them. And yes, I even use St. Jude from time to time, but have no speaking agreement with them. I do not use Biotronik, nor have any agrement with them.

Please check Ann's list - I have no clue who she uses.

Now, how about you?

DrWes said...

Gosh, the comments are coming fast and furious, aren't they?


"not only does it work wes, but its the underlying cause of scd..."

I suppose the heart attack they suffered has nothing to do with it...

Regarding your questions regarding why doctors are buying the machine. This deserves some comment:

ICD companies have seen a recent large decrease in their sales of devices thought, in part, because of the negative publicity about recalls, etc.

Recently, St. Jude Medical (a manufacturer of ICD's) agreed to help distribute the Cambridge t-wave alternans machine company and made a $12.5 million dollar equity investment in the company. Now, did they do this because they wanted to decrease the number of inappropriate defibrillators implanted? (That would go against their business plan, would it not?) No, they know that if enough doctors do enough of these tests on patients, even those who come up "indeterminant", that they'll be forced to implant an ICD, and in actuality, the number of devices implanted is likely to grow. As such, some cardiology practices and hospitals who make revenue on device implants are looking for anything to change the downturn in ICD implants recently. So conflicts of interest abound on both sides, don't they?

Anonymous said...

Come on Dr Wes, You know that 95% of the patients that come to you and depend on your judgement for their well being because you are the "expert". Do you even mention the non-invasive MTWA as an option? Do you talk every patient into an ICD? probably not. As an industry that still has over 400K die annually from SCD, how else can you help identify some of these? wouldn't you concede there is a population that would consent for a non-invasive screening test that might help identify them, those 45-60 year old patients that don't even know that their at risk? The ones like Mr. Terrance Padden, 57, the Cresco man that died of Sudden Cardiac Death just before the vehicle he was driving left the road and struck the concrete over-pass. Would the non-invasive MTWA test identified this person? Maybe Maybe not. At least it would have possibly given him a non-invasive opportunity. Did he pass on an Ep study. We don't know. But I can bet you've had patients that have walked out of your clinic with the " I'll think about it" answer to the invasive EP study.

DrWes said...

Sayspine -

Funny how we've gone from putting in too many defibrillators to not putting enough of the devices, all in one thread, eh?

But to speak to your point - the topic that started all of this was "defibrillator complacency." I agree with you that too many people die without the benefit of ICD therapy - especially those at high risk for arrhythmic death. I also agree with you that EP study in non-ischemic patients is worth a damn - and it is in this group where t-wave alternans holds promise, I believe.

But I am not ready to make t-wave alternans a screening test for appropriate patients at risk either. The false positive rate is just too high for that. Further, prospective randomized mortality trials have not been performed to justify the safety of that approach.

Anonymous said...

Dr Wes,

Do you think too many are being put in patients that won't derive the benefits of what is intended and not enough are going in patients that do need them, some of the 400K a year that still die. Wouldn't a screening device of a non invasive nature, utilized by more MDs find some of those 400K.

And I can assure you, prior to March 21, 2006. MTWA was DOA. Medtronic tried it's best to see to that. But in the meantime the ICD registry is counting and calculating. Not soon enough, IMHO, you'll be asked/demanded to risk stratisfy your decision on your Medicare 35% EF or below ICD candidates. 98% is too strong of a number for Medicare to ignore. You may, but they wont.

Anonymous said...

Do you still do the EP study even though it's "worth a Damn"?

How many of those "worth a Damn" studies are done daily nation wide and ICDs implanted based on those?

What kind of prospective randomized study would you recommend that the EP community and the ICD industry would ever accept? Have you or HRS proposed this study? Is there even a chance of this type of study that could ethically be done?

In the meantime, let's all watch Medtronics lame duck ad campaign try to sell some more ICDs to the unknowing public that doesn't really understand what's going on.

DrWes said...


None of our tests (EP study, t-wave alternans, EKG, echocardiography, CT scanning, etc) are worth a damn in its own context at determining risk for SCD. We do the best we can with the limited data from trials available to us when recommending or not recommending an ICD to a patient. But we cannot discard the results of carefully controlled prospective mortality trials done to date. Unfortunately, such trials are difficult to extrapolate to a more general "at risk" population.

Will Medicare force the performance of MTWA testing before any ICD is implanted? I'm not sure.
Certainly it's NEGATIVE predictive value seems to be good (that is, a negative test suggests low likelihood of death if the device is not implanted), but the comparitively poor POSITIVE predictive value of this test, especially as it applies to the entire population of cardiac disease patients out there getting treadmill tests, risks costing Medicare even more than they are spending now.

One trial that might hold up that requirement by Medicare is the ABCD trial, since it showed MTWA testing to only be about as good as EP testing at targeting the ICD primary prevention population. There seemed to be some reassurance amongst the commentators that BOTH EP and MTWA might be enough to reassure them that it would be safe NOT to implant a device, tho' data showing safety of that approach are not available.

Trial design to test this is fairly easy, and would require ALL patients considered for ICD to have an t-wave alternans testing AND ICD implantation, and follow them for 5-10 years to see what happens. Will t-wave alternans predict whose life would be saved by the ICD? What about the infection rate or inappropriate shock rate of ICD's? We could see, couldn't we? But the expense of that trial would be significant, since the event rate in either arm would be low. Will the device companies and Cambridge step up to the plate?

For the record, I also was not a proponent of the Medtronic direct-to-consumer campaign.

Anonymous said...

Dr Wes, Do you know of any reason why the release date of the Masters 1 trial in conjunction with Medtronic has been delayed? What about the Refine trial from Canada? The ABCD trial did in fact show that both the EP test and MTWA indeterminant/positive worked best together in determining the patients at risk at SCD. But once again, like every other trial to date, the MTWA negative test on patients with nonischemic cardiomyopathy showed that 1/3 would not derive the benefit of the ICD with a 98% accuracy.

What about the Alpha study just relaesed last month in Denver?

How much information and studies do you guys need to make an informed decision?

We can discuss this all day but the same thing will continue for now. 1/3rd of the low hanging fruit(patients) targeted by HRS and the ICD industry will keep getting unneeded implants while hundreds of thousands go unfound and untreated.

You mentioned the possibility of increasing the cost to Medicare by finding these patients. Caught early enough, how many of these would actually need an ICD? Some, but not all. Most could probably be managed by prescription drugs, not ICDs. Of course that would be counter to St Judes intentions wouldn't it.

Anonymous said...

wes..did u disclose your mdt ties in your blog?

all you have to do is listen to comments at morgan stanley and deutche this week form stj and you will understand their plan to lose patients who test neg while gaining from increased population pool of missed patients..since the old way wasted icds on people who didnt need them, and excluded patients who did..the argument has never been we dont believe in icd usage....i hope you sell 1 million icds, as long as the idea is to utilize the best tools at your disposal to find the most appropriate patients...I believe icds can be an effective tool to help patients survive sca, however the way mdt took advantage of the expanded criteria, and dumped mtwa, is not acceptable,,,why you guys fear mtwa so much i understand 100% but i will not bother to even engage you there, other than to say i know why,,,,,, the ultimate hypothetical goal is to implant 400,000 in the exact 400,000 that will die each year..using the system you are hanging on to with dear life, you would have to implant 6 million people..using mtwa could reduce that to 2.8million, so dont worry you'll have plenty of money left over to maintain your lifestyle, and you wont have to ruin as many lives.....

Anonymous said...

Dr Wes,

I would like to apologize for Brian Hassine (dflawed); he is just a jeweler from Mission Viejo, CA who has foolishly poured his entire life savings into this company. He attacks anyone who will not say something good about the company. He is a pathetic soul, and better off ignored.

Anonymous said...

Dr Wes,

Also be aware that Brian Hassine (dflawed), is one of the greediest and most self-serving individuals I have ever met. He claims to own a significant amount of stock in Cambridge Heart Inc, although the number he states is probably as bloated as his ego; still he badgers those who do not share his point of view. Brian Hassine is like a piece of gum stuck to the sole of your shoe, scrape him off with a stick and then forget about him.