Does AVR present less risk of stroke?

nefarious_muse · Oct 29, 2003

Hello All,
I was discussing my husbands AVR and occasionally drifting INR levels with someone the other day, and they mentioned that it is less likely for those with aortic placement to stroke (!) Is this true? I have never heard this before...but wanted to check with you experts!!!

Thanks so much for your time

Nef

Kim · Oct 30, 2003

I have read in several different sources that the aortic valve is less like to form a clot than the mitral valve. I believe it is because of the location of the valve and that blood flows faster in the aortic than the mitral valve. This is why the INR level is generally lower for the aortic valve

Guest · Oct 31, 2003

Kim has it right. However, the risk is only slightly lower. You can get by with an INR of 2.0 to 3.0 for an aortic valve. But this is not really a very significant difference.

JimChicago · Nov 1, 2003

What should be the INR range for a mitral valve. I have both aortic and mitral St Jude valves, everyone testing me says the goal is 2.5 to 3.5 - is this accurate or should the INR range be higher for a mitral valve?

Guest · Nov 1, 2003

I usually keep anyone with any mechanical valve at 2.5 to 3.5. The mitral needs the higher range so you should definitely be at 2.5 to 3.5. There is very little risk of bleeding with an INR below 5.0.

khan2 · Nov 11, 2003

I'd definitely agree that the risk of stroke (embolism) is generally higher in patients receiving a mitral prosthetic valve than an aortic prosthetic valve. However, in an article I published on our first 1,000 St. Jude valves in 1994, we did not see a significant difference:

"With 4328 patient-years of follow-up, 83% of the mitral group, 76% of the aortic group, and 77% of the double valve group were free of thromboembolism at 10 years after operation,"

The St. Jude Medical valve. Experience with 1,000 cases. Khan S, Chaux A, Matloff J, Blanche C, DeRobertis M, Kass R, Tsai TP, Trento A, Nessim S, Gray R, et al. J Thorac Cardiovasc Surg. 1994 Dec;108(6):1010-9; Division of Cardiothoracic Surgery, Cedars-Sinai Medical Center, Los Angeles, CA 90048.

The general recommendation with the St. Jude valve is to run the INR 2.5-3.5 with aortic St. Jude valves being kept at a target of 2.5 and mitral St. Jude valves at a target between 3.0 and 3.5. Since there is some natural variation in the INR, this should hopefully result in the aortic patients running an INR between 2.0 and 3.0 (with an average of 2.5).