Cardiac Surgery - ON-X Post Approval Clinical Registry Study

ON-X Post Approval Clinical Registry Study

Dr. Robert Hagberg and the Cardiac Surgical Team will evaluate the On-X aortic valve performance in normal general open practice using a new lower anticoagulant (blood thinner) dose approved and recommended by the United States Food and Drug Administration (FDA) in 2015. The blood thinner is warfarin (Coumadin® or other brand). The level of warfarin in the blood is determined by blood tests that measure blood clotting times using the term International Normalized Ratio (INR). The INR determines the appropriate dose of warfarin to take. After the first 3 months of standard warfarin therapy (immediately if subjects have already had a valve for 3 months) subjects will have a target INR of 1.8 (1.5 to 2.0 range), which is lower than the previously recommended target INR.

For the study, subjects will choose the follow-up method for INR monitoring, either measured and monitored monthly at an anticoagulation clinic or measured and monitored weekly using a home monitor. The manufacturer recommends the home monitor method, if either subjects or their insurance will pay for it.


  • at least 18 years of age with an On-X aortic prosthetic heart valve implant
  • Life expectancy of at least 5 years

Please contact Nadine Pratt at 860-972-5798 or email for more information