Why bridging?

[Elcarim]

Okay, need all you clever people to help me understand the theory behind bridging. So you go for a procedure that involves bleeding, 'they' think that the sort of bleeding you do when on coumadin will be dangerous, so they put you on a different drug. But still a drug that slows clotting... won't this drug still make you bleed for longer? Causing the same risks that you would have had if you were kept on your regular dose of coumadin? With the difference being that your regular dose of coumadin is easier to manage and maintain an appropriate INR on? Thus preventing the pendulum effect if you have to stop taking it and then start again?

It just seems a bit silly to me... a bit like 'well, you can't take that drug while we operate because it makes you bleed more, but here, have this drug instead. It makes you bleed more.'

I know that different anticoagulants work in different ways, but if they are all going to slow clotting, why not stay on the one that slows clotting in a way that, for example, is most likely to protect my artificial valve?

 

[Nancy]

The types of Heparin they use for bridging leave the system very quickly, not like Coumadin which takes about 3 days to react in your system. So they can bridge you up close to the time when you will need the procedure and then can withdraw it fast and get the procedure done, and put you back on bridging afterwards for a while until you are stable enough to go for the longer term Coumadin.

 

[Marty]

Think "half-life"

Think "half-life"

The idea of bridging is based on substituting an anticoagulant with a long half-life warfarin 2.5 days with an anticoagulant lovenox- 2-3 hours.
One way to bridge is 1. stop warfarin 4 days before surgery. 2. start lovenox 2 days before surgery.3 No lovenox day of surgery( we don't want any anticoagulation during surgery!) 4 start lovenox after surgery if there is no bleeding 5 start warfarin but continue lovenox until INR is over 2.5.
The window without anticoagulant is shortened by bridging.

 

[Bina]

Echoing the others: Heparin can be controlled very quickly, warfarin cannot.

 

[Elcarim]

Ah, that makes sense. Thank you

 

[Ross]

They are beginning to realize that leaving you on Coumadin is less of a risk, then bridging. Heparin does cause you to bleed far more then Coumadin would. Don't get excited. It's going to take decades for this to catch on.

 

[Marty]

And-most common in this area. No bridging. Simply hold warfarin 4 to 5 days before surgery. The doctors I have interviewed say they have had no complications from holding.
This came up in the Meade litigation. Don't know the final verdict. Anyone else hear anything? Also remember Al Lodwick's caveat- " It must be noted that US FDA has never given approval to using any heparin or low molecular weight heparin as a bridge therapy when warfarin must be stopped"!

 

[Ross]

http://products.sanofi-aventis.us/lovenox/lovenox.html#section-8.7

8.6 Patients with Mechanical Prosthetic Heart Valves
The use of Lovenox has not been adequately studied for thromboprophylaxis in patients with mechanical prosthetic heart valves and has not been adequately studied for long-term use in this patient population. Isolated cases of prosthetic heart valve thrombosis have been reported in patients with mechanical prosthetic heart valves who have received enoxaparin for thromboprophylaxis. Some of these cases were pregnant women in whom thrombosis led to maternal and fetal deaths. Insufficient data, the underlying disease and the possibility of inadequate anticoagulation complicate the evaluation of these cases. Pregnant women with mechanical prosthetic heart valves may be at higher risk for thromboembolism [see Warnings and Precautions (5.7)].

 

[Marty]

That's it Ross. That's about all there is. However my gut non-scientific feeling is that it is probably OK to hold for a-fib and DVT in the legs but probably should bridge for mechanical heart valves.

 

[Ross]

I agree, it's not worth the risk, even if there is no real documented evidence.

 

[twinmaker]

I think I've also read that there is more of a problem of not bridging in people with mechanical heart valves in the mitral position.

 

[Cris N]

I am very grateful to whoever trained the doctors in my area. I've had 2 surgeries since my OHS and both times the docs were okay with 2.0. So was I.

 

[Marty]

That's true, Twinmaker- and for that reason I would have a bridge before major surgery.

 

[NewValveNY]

Great postings! Thanks for the info. I'm going in for my first colonoscopy screen and doing bridge therapy. If anyone has any suggestions for injecting Lovenox, kindly send me a note... Thanks!