Bridging Therapy question

[Barry]

Just want to see if I got it right from what I've read here:

1. Heparin works as bridging therapy when the docs have to be cutting on you for some reason because it has the same anticoagulant effect of Warfarin, but it has a much shorter half life. So they can discontinue the heparin before surgery, and during that time your clotting factor is at a level that would be dangerous over time but it's at that level only for the duration of the surgery - and then after the surgery they start the heparin back up and your INR goes back up with it. Then transition back to Warfarin and off you go. Izzat right?

2. There are different kinds of heparin, but the best is the good ol' industrial strengh heparin that you gotta be a hospital inpatient for. That there are low molecular weight (whatever that means!) heparins, such as Lovenox (I think that's the name) that don't require inpatient care, but they don't work as well. Izzat right?

And if I got #2 right, and there are different kinds of heparins, what's the name for the good old-fashioned industrial strength heparin they give you as a hospital inpatient? (Good info to have to make sure that's the kind they give you.)

 

[geebee]

You got #1 right but I don't know any technical name other than heparin. This is the only bridge therapy my cardio will use with me because of my history with TIAs (he even did a cath once while my INR was 2.6 - really made the cath lab nurses crazy).

Have never used Lovenox so can't answer any questions about it other than the above notes.

 

[tommy]

Hey Barry,

As I get it, Herparin is called Heparin and Low Molecular Weight Heparin includes Lovenox (there may be other LMW's?).

I don't know that one is better than the other, but Heparin has shorter life than Lovenox, so provdies more flexibilty if you need to stop it. Also, Lovenox is contra-indicated for some (such as Gina), and some have adverse reaction to it.

I'm coming off a Lovenox bridge right now. I've posted a bunbh on my history in the Coumadin section. Free free to look up those threads.

 

[Guest]

The reason for the low-molecular weight heparin (Lovenox) is that the old heparin (unfractionated heparin) is very hard to manage. So you need repeated blood tests about every 6 hours to get it regulated. To make LMWH they cut off the part of the molecule that makes it hard to manage.

LMWH is actually easier to manage and no less effective than UFH. But a few years ago it was mismanaged in some women in Africa who were pregnant and had mechanical valves. As a result 5 of 100 died. The FDA then said that it was not to be used in anyone with a mechanical valve. Eventually they saw how stupid that was and lifted the prohibition. Now there is no recommendation for or against it. But there are lots of pretty good studies showing that it works. But the political climate at the FDA will not support making a recommendation.

Meanwhile there are some doctors who insist on using UFH even there are no studies proving that it works. But there are no studies proving that it doesn't work either. So it is like they have Grandma's old recipe and whether or not it is healthy they are going with that because that is they way that we have always done it.

To complicate this even further David Garcia, MD (cardiologist who does a lot of anticoagulation research and Ed Libby, MD (cardiologist-hematologist & a good friend of one of my strong supporting doctors at work) published a study about the economics of bridging. They used the model that Medicare (and thus just about every other insurance compant) uses for determining cost effectiveness. The used a hypothetical cohort of men and women with mitral St. Jude valves and atrial fibrillation. Medicare uses $500,000 per quality adjusted life year as the cut off point for whether or not something is cost effective. They found that using UFH instead of LMWH produced an expense to the insurer $3,000,000 higher per QALY for using unfractionated heparin. Since this is 6 times higher than what is cost effective, you can expect that Medicare and other insurers will take a hard look at whether or not they are going to pay for hospitalizations to manage UFH. They estimate that 4167 people would have to be hospitalized for UFH to reduce the number of complications by 1 event compared to using LMWH.

This was in a journal called Journal of Clinical Outcomes Management 2005;12:25-32. It is written specifically for insurers etc to make decisions about whether or not they will provide coverage in upcoming contracts.

 

[Barry]

Thanks! If I got it right, low-molecular weight heparin (LMWH) is just as effective as crummy old unfractionated heparin (UFH), and UFH is easier to manage. But while LMWH is more cost-effective than UFH, we're likely to get UFH because of the conservative approach of the FDA and most docs.

Would you recommend that when put on heparin that one ask the doc to use LMWH? If so, what would be the advantages for the patient? [management difficulty and cost-effectiveness, at least to my mind, speak more to advantages for hospital staff and for the third-party payer, not necessarily for the patient]

 

[Guest]

LMWH was more cost effective and it is easier to manage - no monitoring for people with normal kidney function. Unless there is a special circumstance, I recommend Lovenox. One other point, it is very easy to reverse the effect of UFH but almost impossible to reverse LMWH if it is overdosed.

The advantages of LMWH
None for the hospital staff because you spend all but the last few hours at home.
Big$$$ savings for insurance companies.

Disadvantage of LMWH - when something goes wrong it goes really wrong, like what happened to Joe.

The people who do the best are LMWH bridged without complications
In the middle are the UHF and no bridging people
Next are the bridged (either LMWH or UFH) with complications.
Worst outcomes are unbridged who had complications

 

[Barry]

...you spend all but the last few hours at home...

You sure got my attention with that one! Because of pre-op and post-op hospital days using UFW for bridging, getting a pacemaker installed cost me a whole lot more than it would have had I not been on Coumadin.

With LMWH you begin the bridging at home? Could you please explain that? You do an IV at home?

And with post-op bridging 'til the Warfarin kicks in, is that still done on an inpatient basis with LMWH or do you do at least some of that at home?

 

[Guest]

LMWH is not IV. It is in the belly like insulin.

 

[tommy]

Barry,

My Lovenox shots are twice per day 12 hours apart. It's a small needle shot into the outer flesh in the belly, not into muscle. I have done all of my own (yes - self inflicted) Lovenox shots at home.

 

[Barry]

I have done all of my own (yes - self inflicted) Lovenox shots at home.

And you're here to tell the tale, so clearly it works!

Thanks to all for your responses.