- Nov 4, 2012
- Queensland, OzTrayLeeYa
Can you please link your source? Perhaps you are citing a different study
The tabel you posted above is this, right?yes
not significantly so ... btw, do you know what it is I'm talking about (I didn't cite it)
not significantly so
nope ... just wasn't sure if you knew the indirect "idiomatic" reference ;-)Hope I'm not totalt out of bounds here
I wouldn't discharge the age difference in age as of low significance.
Lowering IT mean age 49, Proact 55.
Also the "Dutch Study" has a much much greater significance in terms of statistics both in the number of people involved and the durations (wouldn't you agree?)
but the study I am quoting is this:Dutch: 483 patiens for 1.149 p-years (Mec Valve)
Lowering IT: 396 patients for 2.217 p-years
Proact: 375 patients for 1.426 p-years
LOWERing the INtensity of oral anticoaGulant Therapy in patients with bileaflet mechanical aortic valve replacement: results from the "LOWERING-IT" Trial - PubMedLOWERING-IT trial established that the proposed LOW-INR target is safe and feasible in low-risk patients after bileaflet aortic mechanical valve replacement. It results in similar thrombotic events and in a significant reduction of bleeding occurrence when compared to the conventional...pubmed.ncbi.nlm.nih.gov
It's the Lowering IT study you linked to in your earlier post regarding the 1:3 ratio.
On-x is not the only valve out there. I have a St. Judes' leaflet valve and it has been since 2001, so it has been 22 years in September. Most hospitals offer what the hospital will allow. But with the St. Jude and On-x valves you do still have to take a blood thinner, but you test more on the St. Jude to adjust the medication.One reason might be that the On-X valve is being used almost exclusively a lot of the major heart surgery centers. Examples: My hospital (Washington D.C. Hospital, MedStar) will install an On-X. I don't even know if they install other mechanical valves . Not mentioned or discussed. And I didn't know any better to ask. The On-X was recommended by my surgeon (for the good or the bad ). There are other major centers that are the same like the Franciscan Health Heart Valve Center.
I am very curious as to the number of On-X aortic valves installed in the past 2 years as compared to the St. Jude's here in the states. Not sure if that data is even available .
FWIW, ball smashers are only being used by angry spouses at this point right? (relax everyone, just a joke!).
Sorry, that makes no sense whatsoever.On-x is not the only valve out there. I have a St. Judes' leaflet valve and it has been since 2001, so it has been 22 years in September. Most hospitals offer what the hospital will allow. But with the St. Jude and On-x valves you do still have to take a blood thinner, but you test more on the St. Jude to adjust the medication.
I see ... as I suspected you're pulling out the data which you feel doesn't match your selection criteria. However I don't think that's fully valid unless you are looking only at the stroke levels (which we are) but there is still value to be had from the other groups in that (I can discuss if you like). For instance can you be sure that no amount of afib will be present in your patient? What amount of platelet aggregation is being triggered by other factors than "mechanical valve". It becomes vexed and in my view requires a more deft and skilled hand at determining discounting than I feel I have. If on the other hand you feel you have more experience than me and better training in the analysis of study data then as long as your confidence is high in that its fine..Lowering IT and Proact is strictly looking at Mechanical valves. The dutch also includes Atrial Fibrillation and Myocardial Infarction (majority of patients). It wouldn´t be fair or give us any valuable information to compare LowIT and Proact to something different then they try to answer. Apples to apples and pears to pears.
Reading and analyzing research data on a daily basis has been a part of my job for the last 15 years so I feel pretty at home. (Not about heart valves and warfarin though.) The more you learn, the more humble you get too however, due to understanding how often you make mistakes and how little you actually know from the whole picture.as I suspected you're pulling out the data which you feel doesn't match your selection criteria.
well I wasn't directly calling it cherry picking but would wonder about discounting things which may be related.But maybe you´re right about the cherry-picking? I have to think about it. Not a bad outcome from a discussion either. Self-reflection.
When I asked about the On-X before my surgery, I was told that the hospital didn't stock it but if I wanted it my surgeon would get it in. I asked why they didn't stock it, and the surgeon said they only have so much room and his valve of preference was the St. Jude. They have to have valves on hand for emergencies, but any valve can be ordered. I asked why St. Jude was the one in stock and he said it had a long history of good performance and he preferred historical data rather than something new with less data on long term use.I am not sure that this is an accurate statement. Once these devices are out in the real world the reporting on problems becomes much less stringent. Having a stroke with a mechanical valve is a known complication and would not necessarily trigger a report to the FDA.
Usually the device manufacturers will negotiate pricing with the hospital or hospital system for the best deals on the devices. If the surgeons don't complain too much these have now become often corporate decisions. As far as the corporate world is concerned if the device is FDA approved it is OK. What levels of anticoagulation have nothing to do with these corporate decisions.
Basically if you are more worried about bleeding go low on your INR. If you are more worried about strokes go higher. Personally I am more worried about strokes so an INR of 2 or less makes me nervous.
In all the studies I have seen with low INRs the stroke rates are higher with the low INR patients. This absurd statistic of combined stroke+bleeding which usually looks favorable for the low INR group is a dumb statistic. The effects of strokes and bleeding usually are quite different.
Ultimately I don't think the people working for these companies are inherently evil but they have their biases and the bottom line is they have to sell these devices to survive.
Doctors are also inundated by these "detail" people who push their products. Doctors are not all knowing and don't have the time to research ever little detail. So they can be influenced by these detail people.
I as a physician have always been leery of what I hear from them when they come to my office. But they clearly have influence or the drug/device companies would not continue to employ them.
My practice is involved with a large number of drug studies on eye drugs for various retinal conditions. When these studies are initiated a lot of thought goes into trying to design the study as likely to work as possible. Recently one of the drug companies had a failed study. They analyzed the study and decided that the way it was set up allowed the study to fail. So feeling confident that their product would ultimately pass muster they set up another study done slightly differently which they hope will succeed. This INR stuff is a lot like that. Concoct weird statistics (adding bleeding+stroke) showing they are "superior" in one group and getting the FDA to OK this device. Also I think there is a trend for the FDA to OK things that possibly in the past would not be OKed. For example one of the drugs for Alzheimers was authorized even though it did not show direct clinical efficacy for Alzheimers. It only showed a marker being altered. Somewhat like the defense industry in the US there is a revolving door between government and industry in other departments like the FDA. So there may be conflicts of interest in making these decisions.