MCRI Granted FDA Approval to Conduct Reduced Anticoagulation Clinical Trial of On-X

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Dustin

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Dec 16, 2005
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Successful completion could result in first-ever low-dose anticoagulation therapy recommendations for a mechanical heart valve



AUSTIN, TX (January 10, 2006) ? Medical Carbon Research Institute L.L.C. (MCRI?) today announced the U.S. Food and Drug Administration (FDA) has approved an investigational device exemption (IDE) clinical trial of the On-X® Prosthetic Heart Valve at reduced anticoagulation levels following local Internal Review Board (IRB) approvals. Successful completion of the clinical study could result in the On-X valve becoming the only mechanical heart valve approved for low-dose anticoagulation therapy.



Based on existing clinical data and the submitted protocol, the FDA has determined that a clinical trial of the On-X valve with three specific patient groups at reduced anticoagulation levels is clinically reasonable. The patient groups include low-risk aortic valve replacement patients, higher risk aortic valve replacement patients and mitral valve replacement patients. Higher risk patients include those with heart rhythm problems, left ventricular dysfunction, previous thrombo-embolism and condition of hypercoagulability.



The low-risk aortic patient group will be maintained using non-warfarin anticoagulation medication of clopidogrel (Plavix®) and aspirin. Higher-risk aortic patients will be maintained using warfarin (Coumadin®) at reduced International Normalized Ratio (INR) levels of between 1.5 and 2.0, plus aspirin. The mitral valve replacement patients will be maintained with warfarin at a target INR of 2.0 to 2.5 and aspirin. The first three months for all patient groups include traditional warfarin anticoagulation protocols. To ensure that patients remain within target INR range, each patient will be required to self-monitor their anticoagulation levels. Results of this self-monitoring will be communicated to the patient?s physician.



The investigation will be led by John D. Puskas, M.D., associate chief, Division of Cardiothoracic Surgery at Emory University School of Medicine in Atlanta, Ga., and is expected to be complete after five years of follow-up.



"This is the first FDA trial to explore lower anticoagulation with mechanical heart valves," said Dr. Puskas. ?The On-X valve has design and material features that make us hopeful that it may function well at lower levels of blood-thinning medications. If this trial proves what we believe it will, On-X valve recipients will be able to take a lower level of anticoagulant, which will reduce the potential incidence of bleeding complications caused by taking the higher dosages of Coumadin normally prescribed after receiving a mechanical heart valve."



According to The American College of Cardiology and the American Heart Association?s ?Guidelines for Management of Patients with Valvular Heart Disease,? the standard of care for three-months postoperative is anticoagulation therapy with warfarin at an INR of 2.5 to 3.5 for both mechanical and biologic (animal) tissue valve replacement patients. Recommendations for biologic valve patients three months postoperatively are 80 to 100 mg/day of aspirin. After three months, mechanical valve postoperative anticoagulation therapy advises the use of warfarin at INR levels of 2.0 to 3.0 for aortic valve replacement patients without risk and 2.5 to 3.5 for aortic valve patients with risk and mitral valve patients. Although warfarin has a long history of safe use, it has the potential side effect of bleeding.



?The "holy grail" for cardiac surgeons implanting heart valves has been ?A Valve for Life?," said Sidney Levitsky, M.D., Cheever Professor of Surgery at Harvard Medical School and director of Cardiothoracic Surgery for CARE Group, Boston, Mass., and chair of the Reduced Anticoagulation Clinical Trial of the On-X Prosthetic Heart Valve Data Safety Monitoring Committee. ?To avoid clotting, presently accepted mechanical valve postoperative care mandates high levels of anticoagulation with warfarin, which is associated with bleeding problems varying from minor episodes of hematuria (blood in urine) and melena (blood in stool) to intracerebral hemorrhage. If the approved FDA reduced anticoagulation study is successful, the On-X valve will become the safe valve of choice for a new generation of patients who are expected to enjoy a long life, and we will finally approach the concept of ?A Valve for Life?."



"The On-X valve may be the next step in the evolution of valve technology," said Hillel Laks, M.D., professor and chief of Cardiothoracic Surgery and director of the Heart, Lung and Heart-Lung Transplant Programs at UCLA School of Medicine. ?This study is significant because of the larger numbers of older valve patients who are living longer. Traditionally, these patients would receive tissue valves to avoid the bleeding risk associated with taking higher levels of Coumadin. However, when tissue valve patients live into their 80s and 90s, they run the risk of having replacement surgery in eight to 16 years when the tissue valve wears out. This FDA study has the potential for changing our choices in heart valves in the future. If we can show that it is safe to use a mechanical valve with low levels of Coumadin or alternative drugs that are safe?or even no Coumadin?the choice in these borderline older patients will be completely different.?



"After decades of heart valve research and design, we have developed what could be the first prosthetic heart valve to combine the durability of a mechanical valve with the reduced complication rates of tissue valves,? said Jack Bokros, Ph.D., MCRI's founder and chairman. "The approval to conduct this reduced anticoagulation study is further evidence that the On-X valve merits study under this protocol. The success of the study could provide proof that the On-X valve is truly a breakthrough medical advance in heart valve prosthetics, providing patients with the benefits of both mechanical and tissue valves: a valve that will last a lifetime without the potential complications of taking high dose anticoagulants.?



Clinical centers and patients are now being recruited for the On-X reduced anticoagulation study. The study is limited to 1,200 patients and 20 institutions. Interested parties should contact John Ely, Executive Vice President of Regulatory and Clinical Affairs for MCRI, at 888-339-8000 ext. 226 or [email protected]. Information and updates for this and other On-X Prosthetic Heart Valve studies are located at www.onxvalves.com or by contacting MCRI.



Until the completion and analysis of study data, MCRI continues to recommend standard anticoagulation therapy as presently prescribed by various professional societies for the On-X valve.



Other Non-Randomized Reduced Anticoagulation Trials in Progress

For the past year, a non-randomized observational study of On-X valve patients under standard labeling indications with an INR target range within?yet at the lower limits of?American College of Cardiology and American Heart Association guidelines, has been conducted by Cardiac Surgical Associates (CSA) and the Tampa Bay Heart Institute. The study employs home monitoring to aid control of the anticoagulant therapy. The study has not reached significance, but according to Vinay Badhwar, M.D., ?the observed results of our non-randomized reduced anticoagulation trial with the On-X valve are extremely encouraging. The lack of bleeding complications and the combination of a durable prosthesis with manageable low INR anticoagulation is providing patients with significant lifestyle improvements.?



In South Africa, 438 On-X valve patients have been followed (95 percent) for five years. The patients are documented to have varying amounts of anticoagulation. Approximately 14 percent of On-X patients were categorized as having ?unsatisfactory? or anticoagulation below 1.5 INR. Another 29 percent had ?no? or ?unknown? anticoagulation, which was attributed to poor patient compliance to established protocols. The remarkable aspect of the study is that among aortic, mitral and double valve replacement patients, only one (0.2 percent per patient year) patient experienced thrombosis.



More about the On-X Prosthetic Heart Valve

The On-X valve is the result of a breakthrough in medical grade carbon technology: On-X® Carbon. In addition to providing a more thrombo-resistant surface, the pure On-X Carbon enabled MCRI to make significant valve design changes that resulted in a prosthetic that treats blood more like a natural valve. It is well documented that the On-X valve does not produce the turbulence and blood damage commonly produced by other mechanical heart valve prosthesis and therefore significantly reduces the potential for life-threatening blood clots.



First implanted in 1996, recent clinical evidence suggests that patients implanted with the On-X heart valve may be able to forego or reduce the dosages of anticoagulation therapy traditionally required by mechanical heart valve recipients.



The FDA approved the On-X aortic and mitral valves for commercial use in the United States on May 30, 2001, and March 6, 2002, respectively. More than 40,000 On-X valves have been implanted since 1996.



About Cardiovascular Disease and Heart Valve Replacement

Cardiovascular disease is the number one cause of death worldwide. The American Heart Association reports that 95,000 surgeries were performed in the United States to repair or replace malfunctioning or diseased heart valves in 2003. According to a June 2004 report issued by Millennium Research Group, life-threatening heart valve disease, including stenosis and regurgitation, affected approximately five million people in the United States in 2003. Millennium Research Group predicts the heart valve market will generate more than $650 million by 2008 due to advances in minimally invasive techniques, the increasing incidents of cardiovascular disease and the aging population.



About MCRI

Medical Carbon Research Institute (MCRI) develops heart valve replacements that significantly improve the quality of life for patients. Jack Bokros, Ph.D., and his associates founded MCRI in 1994 to advance prosthetic heart valve technology by capitalizing on their new form of pyrolytic carbon. The On-X valve design was awarded a 2002 Medical Device Excellence Award in the Implant and Tissue-Replacement Products category. MCRI also provides OEM services utilizing its patented On-X Carbon to manufacturers of other medical products, including orthopedic joint and spine implant devices. MCRI is headquartered in Austin, Texas, and maintains a wholly owned subsidiary, MCRI Deutschland GmbH, in Hannover, Germany. More information about the company is located at www.onxvalves.com.

Source:
http://newark.dbusinessnews.com/shownews.php?newsid=57400&type_news=past

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This is encouraging news for those who have this valve, or are to receive one in the future. Perhaps this valve offers improved protection against thrombus with conventional coumadin therapy after all. Only time will tell.
 
I sure hope this works out but I wouldn't want to be part of the test group.:eek: :eek: :eek: I am not that brave.
 
geebee said:
I sure hope this works out but I wouldn't want to be part of the test group.:eek: :eek: :eek: I am not that brave.


Yep, there is too much of a risk ending up paralyzed for the rest of your life. However, the improved thromboresistance could give patients some comfort whenever the INR drops too low while on regular coumadin management.
 
Randy & Robyn said:
I'm pushing hard to get this valve and now I will push even harder. :)

Best of luck Randy- Maybe Vr.com should start a letter writing drive.
Think about it! Just let us know who to send it to. This could be the
begining of some very exciting news, that will take away the threat of strokes
and last a lifetime.
 
RCB said:
Best of luck Randy- Maybe Vr.com should start a letter writing drive.
Think about it! Just let us know who to send it to. This could be the
begining of some very exciting news, that will take away the threat of strokes
and last a lifetime.

I may just take you up on that, Bob. I just talked with the sales manager at MCRI and she told me that their sales rep is meeting with Dr. Lytle, the chief of cardiovascular surgery at Cleveland Clinic, today. I should know very soon if I get my chance. A few letters sure wouldn't hurt if they are hesitant. I will be contacting Dr. Lytle personally myself as well.

I have my fingers crossed.

Randy
 
Plavix - 75mg Tablets
Quantity Our Price
30 tablets $116.99


Coumadin - 5mg Tablets
Quantity Our Price
30 tablets $23.99


What do you think will happen?
 
RossTO THE EDIT POLICE---Users may edit their own posts said:
Oh no - don't do that! I'm a fast typer and a terrible speller and often go back 2 or 3 times to correct typos or spelling. If I can't edit my posts then everyone will not see me as the highly intelligent, incredibly stunning woman that I am!:D :D

I'm with Gina and Dustin - If I got an On-X, I'd let someone else be the lab rat for this study. Not exactly an heroic position to take, but I like being able to feed myself. However, once proved, I'd be happy to follow suit.
 
I think it will be interesting (of course a bit down the road) if the study does prove aspirin is sufficient for the On-X, to see if folks with non-On-X mechanicals choose to have their valves replaced.

Maybe worth another poll. Would you choose to have another OHS to get an On-X valve knowing it would more than likely be your last valve and you would be off coumadin? I know I would consider it except for the fact that I have reached my OHS surgery limit for this lifetime.:( :(

I sincerely hope the On-X recipients get to throw their coumadin tablets away (or, at least, send them on to us coumadin junkies).
 
Dustin

Dustin

Karlynn said:
I'm with Gina and Dustin - If I got an On-X, I'd let someone else be the lab rat for this study. Not exactly an heroic position to take, but I like being able to feed myself. However, once proved, I'd be happy to follow suit.

When we take coumadin, aka "rat poison", we should all be called lab rats. :p
 
Ross said:
Plavix - 75mg Tablets
Quantity Our Price
30 tablets $116.99


Coumadin - 5mg Tablets
Quantity Our Price
30 tablets $23.99


What do you think will happen?

Yes, but how much for chill pills, Ross? Sounds like you may need to distribute them to some of our members. :D

No lab rat for me either. I would take my coumadin knowing that I could breathe easier if it happened to drop below 2.0. And perhaps bridging therapy could be avoided for other invasive procedures. That would be a huge plus.

It is interesting that they propose such narrow ranges of the inr in their trials. I remember reading in other threads that it is very difficult to maintain that degree of control.

Randy
 
Randy & Robyn said:
No lab rat for me either. I would take my coumadin knowing that I could breathe easier if it happened to drop below 2.0. And perhaps bridging therapy could be avoided for other invasive procedures. That would be a huge plus.
Randy

Those were my thoughts exactly. Knowing that the On-X shows higher robustness against low INR could give some breathing space and mental tranquillity whenever you drop below 2. I'll choose this valve but wish to remain on conventional coumadin therapy, however.
 
Testing??????????????

Testing??????????????

catwoman said:
How difficult will it be to keep their doses in a 0.5mg range???????

Kind of silly I think, a test can be that far off!:rolleyes:
 
Update:

I have been patrolling some German forums last couple of days and read that those who are on the On-X aspirin-only trials are using the ThromboCheck acoustic monitor to improve the detection of thrombus. Spectrum analysis (Fast Fourier Transform) is used to identify possible valve malfunction through shifts of characterstics frequencies and amplitudes. Patients that have detected 10% shifts have been issued a warning and have been admitted to the hospital for further tests. Those cases showing thrombus underwent trombolysis therapy, showing a return to the patient's baseline acoustic signature.

I'm curious whether this procedure will be applied in the US, where patients send their acoustic signature to the hospital over the internet whenever possible. An online database and analysis service to provide feedback and advice on the valve status. It can be expected that catastrophic valve thrombosis and dysfunction will be reduced by frequent spectral analysis.

We are living in interesting times indeed. Stay tuned.
 
Dustin:

What is an accoustic signature?

And just wondering:

If -- and I stress IF -- aspirin were to be OK'd by the U.S. FDA for anti-coagulation therapy with the On-X valve, what safeguards would be used to detect possible clots? Seems it would require additional tests, instruments, etc.
 
catwoman said:
Dustin:


What is an accoustic signature?

Your "acoustic signature" would be the characteristic sound (frequencies and amplitudes) of your valve right after surgery. So when you use this TC device, you would be recording the sound coming from your valve compared to the sound you had when you just received your valve. So, your acoustic signature is unique and belongs to you only. Any sort of "significant" discrepancy between the sound you record and what you started with may indicate the onset of thrombus or other valve dysfunction. It's comparable to voice recognition technology.





catwoman said:
And just wondering:

If -- and I stress IF -- aspirin were to be OK'd by the U.S. FDA for anti-coagulation therapy with the On-X valve, what safeguards would be used to detect possible clots? Seems it would require additional tests, instruments, etc.

Granted, acoustic valve monitoring is in its initial stage and clinical trials are currently being conducted in Germany. It is argued that frequent spectral analysis of your valve sound is very sensitive and that the smallest thrombus formations could be detected BEFORE the usual ultrasound or flow measurements are able to detect valve dysfunction. So your valve may be operating properly, but the onset of thrombus at hinge points are already influencing leaflet motion in the smallest sense, hence a shift in your acoustic signature will be detectible.

It is argued, however, that the device cannot prevent thrombosis and eventual embolims, but it may be a diagnostic tool that allows us to intervene at earlier stages such that valves can be replaced or treated otherwise. So when your valve goes bad, you are probably detecting it before catastrophic valve dysfunction or embolisms ensue. So the protocol as it is written right now, is that patient undergo further rigorous tests at the hospital whenever the acoustic signature changes for a 10%, say. One last thing, it remarked that your acoustic signature may also be influenced by other factors such as a-fib.

Stay tuned.
 
I am a 37 year old man faced with making that difficult decision of mech Vs. Tissue for an AVR I will be having in the next few weeks. I still havent decided and I have been trying to get as much info in both directions as I can.

I read this article on the site about a week ago and mentioned the On-X valve to the surgeon I will be going to.

He had something interesting to say about this.

He was aware of the trial. he knew all about the valve. He felt there were some interesting aspect to this valve. Felt it was a well made product.

However, he also said that there was no real reason other than marketing to make this valve more likely to suceed with lower anticoagulant use than the St' Judes.

That if the trial itself yileds favorable results no reason a St. Judes valve couldnt follow in this direction based on a comparions of design, materials and specs. However, he also made it clear to me that he wouldnt want any patient of his participating in the trial itself. That the fer of stoke is still there and a real risk. The trail doesnt take that concern away.

Additionaly he didnt like this valve for me for a specific reason. He says that currently the On-X valve only comes in one size, 25. I am 6-2", a big man and he expects to use a bigger valve on me.

I dont know if anyone else is aware that it only comes in one size, but I thought the info might be helpful if this accurate.

I am new to this compared to many others around here so forgive me if this is wrong...but my understanding the bigger the valve the better the flow? It would seem a good reason for some NOT to want this valve.
 
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