On-X For Mitral Valve Replacement?
Vivan has severe mitral regurgitation and is preparing for mitral valve replacement surgery. She is currently considering several different valve types (tissue, homograft, mechanical) and valve brands (Edwards, Medtronic and St. Jude Medical).
Vivian’s question to me is, “Adam - Can you tell me about the On-X valve for mitral valve replacement?”

For those of you who are not familiar with the On-X heart valve device for mitral replacement, here is some basic information for you:
- On-X was founded in 1994 and is located in Austin, Texas. It also owns Medical Carbon Research Institute in Hanover, Germany.
- According to the On-X valve website, the primary focus of On-X is (i) Continually improve pyrolytic carbon coating technology along with supporting processing and inspection technologies, (ii) Advance the level of prosthetic heart valve performance while reducing the level of patient valve-related complications, and (iii) Provide additional cardiac surgery products that uniquely improve patient care.
As for its valve offerings, the On-X® Prosthetic Heart Valve for mitral replacement is a pure carbon bileaflet heart valve prosthesis. One of the most interesting attractions of the On-X valve is that in January of 2006, the FDA approved the first-and-only IDE (Investigational Device Exemption) lowered anticoagulation trial for a mechanical valve to be conducted at 40 sites in the United States for the On-X® Prosthetic Heart Valve.
The patient groups in the PROACT (Prospective Randomized On-X Clinical Trial) study include a non-warfarin group of low-risk aortic valve replacement patients and two low-dose warfarin groups of higher risk aortic and mitral valve replacement patients.
In case you missed that did not make sense… The significance of the On-X trial is that patients may obtain the benefits of a mechanical valve (duration, lower reoperation) without the risks of clotting problems due to lower Coumadin (Warfarin) dosages. I have also heard that some patients are taking Plavix / aspirin instead of Coumadin in an ongoing On-X trial.
According to the company, over 50,000 On-X valves have been implanted since 1996.
I hope this give you some background on the On-X valve for mitral replacement. Over the years, I have spoken with many patients that are happy with their selection of the On-X valve. If you have an On-X replacement valve, please Leave A Comment below and let us know your thoughts!
Keep on tickin!

Adam Pick is a double, heart valve surgery patient and author of The Patient’s Guide To Heart Valve Surgery, a unique book which integrates the clinical facts of heart valve surgery with the personal experiences of an actual heart valve surgery patient. To learn more about Adam and his heart valve surgery book, click here.






August 27th, 2008 at 3:13 pm
I have a 23mm ON-X aortic valve that was implanted on 8-16-08. I am on low dose coumadin at the present and am expecting to go to aspirin and Plavix soon. I have not had any problems other than noise, I hear it clicking away mostly at night or when it is really quiet. It is supposedly quieter than other mechanical valves so I would hate to hear one of those. I do have really good hearing though. My 13 yr old daughter can hear me from across the room though no one else in my family can. We have fun with it, the noise that is.
Good luck with your operation. KT
November 13th, 2008 at 12:14 am
I had a 23mm ON-X aortic valve replacement for a 23-year old high turbulence Bjork-Shiley 21mm on 11/3/08. Bjork-Shiley had a high INR requirement, was highly destructive as well as less efficient than even a St Jude by half an order of magnitude. I suffered intermittent atrial fibrilliations for the majority of the 23 years I had that implant and the sound was substantially louder and simpler. A simple click-clack is now a very quiet overlapping click->click pause. Outgrowing my previous valve I incurred signifigant hypertrophy which was corrected during the on-x replacements. Also, I never suffered from headaches or migranes (without exceptional fever or poison).