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Speak with a clinical consultant:

Mark Spindler

(512) 831-6557


For Patient, Technical, and General Inquiries


Reduced Anticoagulation

  • On-X® Aortic Heart Valve patients should be managed at INR 1.5–2.0.*
  • 65% fewer bleeds, no increase in TE only with On-X Aortic Heart Valves.1-2
  • *Reduce INR after 3 months standard therapy.
  • Learn about the valve’s design
  • See the PROACT study results

Low Thrombogenicity By Design

The On-X Aortic Heart Valve is designed to minimize hemostasis and hemolysis, making it the only mechanical valve that is safer with less anticoagulation.

Less Blood Damage
The On-X valve is the only mechanical valve with average LDH levels in the normal range (below 250 U/L).3 Less hemolysis leads to less platelet activation and less clotting.

Pure Pyrolytic Carbon
The carbon surface of the On-X valve smoother than any other valve, greatly reducing thrombogenicity.

90° Leaflets
On-X valve leaflets open to 90° to minimize turbulence and allow a more natural spiral blood flow.

Smooth Pivots
Only On-X valve pivots are free of sharp corners and machining marks. This eliminates hemostasis by completely purging the pivots with every beat.

Flared Inlet
The flared inlet promotes laminar flow with reduced turbulent shear stress and less hemolysis.

Proact Results

  • 65% Fewer Bleeds
  • No Increase in TE
  • INR: 1.5–2.0
  • 63,000 INR Data Points
  • 33 US Centers
  • Read the article at JTCVS

Learn More
Watch the slide presentation
Request more information



What sewing cuff options are there?

In addition to the standard sewing cuff, On-X also offers the Conform-X aortic cuff and an anatomic cuff.
The Conform-X cuff allow a more flexible fit to the valve annulus. The anatomic cuff is scalloped to fit
the annulus with less distortion. See all of the cuff options here.

Is reduced anticoagulation available for mitral valve patients?

The PROACT study includes On-X mitral valves, but that arm of the study is not yet complete. Reduced anticoagulation results for mitral valves are forthcoming.

What do I need to know about implant technique for the On-X valve?

The On-X valve has a supra-annular sewing cuff with an intra-annular carbon inlet flare. It is important to use sizing and suturing techniques specific to the On-X Valve. Please follow the Instructions for Use and view this Implant Technique Video. Whenever possible, we recommend inviting a company representative to attend the case.


On-X aortic and mitral valves are FDA approved.

Caution: Federal Law (USA) restricts this device to sale by or on the order of a physician. Refer to the Instructions for Use that accompany the valve for indications, contraindications, warnings, precautions and possible complications.


1. Puskas J, Gerdisch M, Nichols D, et al. Reduced anticoagulation after mechanical aortic valve replacement: interim results from the Prospective Randomized On-X© Valve Anticoagulation Clinical Trial randomized Food and Drug Administration investigational device exemption trial. J Thorac Cardiovasc Surg. 2014;147(4):1202-1211.

2. Yanagawa B, Levitsky S, Puskas JD, et al. Reduced anticoagulation as safe in high risk patients with the On-X mechanical aortic valve. Current Opinion in Cardiology 2015; 30:140-5.

3. Birnbaum D., Laczkovics A, Heidt M, Oelert H, Laufer G, Greve H, Pomar JL, Mohr F, Haverich A, Regensburger D., Examination of hemolytic potential with the On-X® prosthetic heart valve. J Heart Valve Dis. 2000; 9(1):142-5.