clay_from_nj
Well-known member
A little evidence behind something we've always been told: Mechanical Valves Beat Bioprostheses in Younger Patients.
A little evidence
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It could also be that the patients who received bioprosthetic valves, on the average, were older and had more comorbidities. We have also been told that the immune systems of younger patients are more active and more likely to attack the tissue of the bioprostheses.
Also, I wonder why a doc from CCF would speak so (apparently) stongly in favor of mech valves when CCF has been moving toward tissue valves for younger and younger patients over the past years.
Also, I wonder why a doc from CCF would speak so (apparently) stongly in favor of mech valves when CCF has been moving toward tissue valves for younger and younger patients over the past years.
clay_from_nj
Well-known member
They controlled for that by only including patients under 60, which they refer to as "very young."
An interesting aside to consider for those who are hoping for a future TAVR:
I would add to that that the TAVR is a mechanical valve and would require anticoagulation therapy, now at an advanced age and when the real danger of stroke and bleeding events really matters.
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I can't access the link. Any chance you could copy and paste so we could read the entire article?
I found the study and have copied what I found. It looks like both groups were 99% free from re-ops.
February 4, 2011 (San Diego, California) — Younger aortic-valve-replacement recipients are more likely to survive another 10 years with a mechanical valve than a bioprosthesis, data from a small series in Switzerland suggest.
"More and more patients come to surgery already knowing and telling us what valve they want. Because of the quality of life, most of them prefer the bioprosthesis, because they don't want to take anticoagulation drugs," Dr Alberto Weber (University of Bern, Switzerland) told heartwire . "But we weren't sure we were doing it right. So we needed to look into our data."
Weber and colleagues tracked overall survival, valve-related adverse events, and left ventricular regression in 101 consecutive patients under the age of 60 who received a biological aortic-valve replacement (Carpentier-Edwards pericardial valve, Edwards Lifesciences). Their results were compared with a propensity-matched group of 91 patients who received a mechanical aortic valve (ATS, St Jude). Total follow-up was 1420 patient-years, an average of 20.7 months. Weber presented the results of the study at the Society of Thoracic Surgeons (STS) 2011 Annual Meeting.
The 10-year survival rate was significantly lower in the patients with the bioprosthetic valve than those with the mechanical valve (89.1% vs 96.7%, p<0.05). Freedom from all valve-related complications was statistically similar, 54.5% for the bioprosthesis group and 52.6% for the mechanical-valve group. Freedom from reoperations was 99% in both groups.
The average aortic mean pressure gradient was higher in the bioprosthetic valve group (11.2 mm Hg vs 10.5 mm Hg, p=0.05), as was the peak pressure gradient (19.9 mm Hg vs 16.7 mm Hg, p=0.03). Regression of the left ventricular mass index was also higher after mechanical-valve replacement than after bioprosthetic-valve replacement, but the difference was not significant.
Commenting on the study at the STS meeting, Dr Tomislav Mihaljevic (Cleveland Clinic, OH) pointed out that some previous studies have shown that mechanical-valve patients have better survival odds than bioprosthetic recipients because the bioprosthetic valves required more reoperations. But those reoperations tended to be close to 10 years after the implant, while in this study, the survival curves appeared to diverge early and the freedom from operation was similar between the two groups. That suggests that the hemodynamic performance of the bioprosthesis was not the main reason for the difference in the survival, Mihaljevic suggested. "I wonder if there could be some patient-related factors that contributed to the early, but substantial, increased mortality in patients who received a bioprosthesis."
Weber responded that since it was not a randomized trial, it is still possible that there was some unknown variable that made the two groups of patients different, but his group carefully looked for potential confounders, so this is not likely the explanation. The more likely explanation is that the mechanical valves worked better over the long run. "The survival of the bioprosthetic valve group is very good and not bad compared with the literature. What is astonishing are the really excellent results of the mechanical valves in this patient group. We had only three patients die out of 101, with quite a high risk. This is good news."
Weber told heartwire that with the advent of transcatheter valve systems, it is possible to put a new valve inside a failed bioprosthesis. But he argued that that possibility is not justification for using bioprosthetic valves in patients under 60. "We're talking about very young patients here. This new 'valve-in-valve valve' isn't going to last for good, so we would be facing, in these patients, two or three or four more reoperations. That's not a solution."
The availability of newer anticoagulation drugs that are easier to manage in the outpatient setting, such as dabigatran , may make patients more amenable to mechanical valves. "It's definitely worth a try to see how these new anticoagulants are going to perform with mechanical valves," Weber said. "It may signify a small revival of mechanical valves, because, hemodynamically, they are better than the bioprosthetic valves."
Weber and Mihaljevic reported no conflicts of interest.
February 4, 2011 (San Diego, California) — Younger aortic-valve-replacement recipients are more likely to survive another 10 years with a mechanical valve than a bioprosthesis, data from a small series in Switzerland suggest.
"More and more patients come to surgery already knowing and telling us what valve they want. Because of the quality of life, most of them prefer the bioprosthesis, because they don't want to take anticoagulation drugs," Dr Alberto Weber (University of Bern, Switzerland) told heartwire . "But we weren't sure we were doing it right. So we needed to look into our data."
Weber and colleagues tracked overall survival, valve-related adverse events, and left ventricular regression in 101 consecutive patients under the age of 60 who received a biological aortic-valve replacement (Carpentier-Edwards pericardial valve, Edwards Lifesciences). Their results were compared with a propensity-matched group of 91 patients who received a mechanical aortic valve (ATS, St Jude). Total follow-up was 1420 patient-years, an average of 20.7 months. Weber presented the results of the study at the Society of Thoracic Surgeons (STS) 2011 Annual Meeting.
The 10-year survival rate was significantly lower in the patients with the bioprosthetic valve than those with the mechanical valve (89.1% vs 96.7%, p<0.05). Freedom from all valve-related complications was statistically similar, 54.5% for the bioprosthesis group and 52.6% for the mechanical-valve group. Freedom from reoperations was 99% in both groups.
The average aortic mean pressure gradient was higher in the bioprosthetic valve group (11.2 mm Hg vs 10.5 mm Hg, p=0.05), as was the peak pressure gradient (19.9 mm Hg vs 16.7 mm Hg, p=0.03). Regression of the left ventricular mass index was also higher after mechanical-valve replacement than after bioprosthetic-valve replacement, but the difference was not significant.
Commenting on the study at the STS meeting, Dr Tomislav Mihaljevic (Cleveland Clinic, OH) pointed out that some previous studies have shown that mechanical-valve patients have better survival odds than bioprosthetic recipients because the bioprosthetic valves required more reoperations. But those reoperations tended to be close to 10 years after the implant, while in this study, the survival curves appeared to diverge early and the freedom from operation was similar between the two groups. That suggests that the hemodynamic performance of the bioprosthesis was not the main reason for the difference in the survival, Mihaljevic suggested. "I wonder if there could be some patient-related factors that contributed to the early, but substantial, increased mortality in patients who received a bioprosthesis."
Weber responded that since it was not a randomized trial, it is still possible that there was some unknown variable that made the two groups of patients different, but his group carefully looked for potential confounders, so this is not likely the explanation. The more likely explanation is that the mechanical valves worked better over the long run. "The survival of the bioprosthetic valve group is very good and not bad compared with the literature. What is astonishing are the really excellent results of the mechanical valves in this patient group. We had only three patients die out of 101, with quite a high risk. This is good news."
Weber told heartwire that with the advent of transcatheter valve systems, it is possible to put a new valve inside a failed bioprosthesis. But he argued that that possibility is not justification for using bioprosthetic valves in patients under 60. "We're talking about very young patients here. This new 'valve-in-valve valve' isn't going to last for good, so we would be facing, in these patients, two or three or four more reoperations. That's not a solution."
The availability of newer anticoagulation drugs that are easier to manage in the outpatient setting, such as dabigatran , may make patients more amenable to mechanical valves. "It's definitely worth a try to see how these new anticoagulants are going to perform with mechanical valves," Weber said. "It may signify a small revival of mechanical valves, because, hemodynamically, they are better than the bioprosthetic valves."
Weber and Mihaljevic reported no conflicts of interest.
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chaconne
Well-known member
Duffey said:
Am I missing something here? I thought the whole reason Mechs needed anticoagulants was because they were worse than tissue valves hemodynamically.
clay_from_nj
Well-known member
Not hemodynamics, but other stuff. (I'll bet pellicle has a good grasp of the science involved.)
pellicle
Professional Dingbat, Guru and Merkintologist
Perhaps basic grasp of the fundaments is more like it ;-)
But I am willing to bet its more complex than we reckon. I've got some interesting refs on haemodynamics and platelet activation in mechanical valves, but I'm not sure this isn't a red herring.
Right now I'm trying to find any studies that discuss just reoperation needs and break that down by valve type and age group. To say there is a dearth is an understatement!
clay_from_nj
Well-known member
Could it be as simple as platelets like to stick to hard, non-slimy stuff? Or maybe it has to do with the valve smashing up some of the blood cells.
pellicle
Professional Dingbat, Guru and Merkintologist
seems that exposure to pressures created by "opening and closing jets" (you can hear them when they do the doppler part of the echo if you're listening for it) causes it. There are known trigger points of 'velocity'.
pellicle
Professional Dingbat, Guru and Merkintologist
this is the sort of study breakdown I'm looking for
this is the sort of study breakdown I'm looking for
This is the abstract of the report from the surgical team in Queensland Australia that did my homograft.
I'd love to see this sort of data (even done as a meta-analysis) on all valves, particularly the way they've broken down the ages
PS: I was done in 1992 (28yo) and had a cryo-preserved valve. And a quiet thankyou to Dr's Greg Stafford and M O'Brien for giving me my second shot at life. (currently on my third go at it) I have tried to make your efforts worth it.
this is the sort of study breakdown I'm looking for
This is the abstract of the report from the surgical team in Queensland Australia that did my homograft.
I'd love to see this sort of data (even done as a meta-analysis) on all valves, particularly the way they've broken down the ages
PS: I was done in 1992 (28yo) and had a cryo-preserved valve. And a quiet thankyou to Dr's Greg Stafford and M O'Brien for giving me my second shot at life. (currently on my third go at it) I have tried to make your efforts worth it.
Or. . . could there be some heretofore unknown benefit derived from the anticoagulants themselves?
This is totally "outside the box" thinking, but it is one definite difference between the two groups. I wonder if there has been any research on this.
Pellicle - have you seen anything like this?
This is totally "outside the box" thinking, but it is one definite difference between the two groups. I wonder if there has been any research on this.
Pellicle - have you seen anything like this?
pellicle
Professional Dingbat, Guru and Merkintologist
I think I'll stay in my box on this one... call "white coat syndrome" ... or just plain yellow ;-)
There are other benefits of anticoagulants, that's why 30% of older patients who get bio valves also are on asprin, warfarin or both for other cardiovascular or pulmonary reasons.
Don't you just love the line about having "game": "Taking anticoagulants for a reason other than a heart valve problem." Yeah I've got "game." Boy I hate that commercial.
Don't you just love the line about having "game": "Taking anticoagulants for a reason other than a heart valve problem." Yeah I've got "game." Boy I hate that commercial.
pellicle
Professional Dingbat, Guru and Merkintologist
Steve
some thoughts
as has been suggested, we're not sure what are younger ... only less than 60yo
my feeling is here that "why are patients telling the specialists whats better for them?"
one of the things which bothers me about many of these things is the total lack of meta-data. I recall during my Masters research (water supply) in wondering why the consultants had chosen a rolling 11 year average for monthly rainfall expectations when the rainfall in the area was clearly seasonal and stochastic. In short their strategy blinded the water utility to the fact that droughts could occur.
a classic example of mushing up the data ... making it seem grand "ohh, one thousand four hundred and twenty years ... cough cough ... oh ok on average just a little bit under two years.
clearly not data from their study an average follow up of 20.7 months
well what do you know ... seeking answers best dug out of meta-data (that was lost) for some horizontal vs vertical analysis.
ok, I'm unclear here ... are they talking about patients in the study being high risk? Then this isn't really representative of younger healthy adults ...
ok ... so what were the age groups? I mean its implied here with two, three four reops there must be some under 40 patients....
I can't understand why data is not presented clearly, say in the style of the long term followup of my cohort (see a post here)
it seems to me like a lot of good data and research is wasted. I can only guess that people really don't want to know.
some thoughts
as has been suggested, we're not sure what are younger ... only less than 60yo
my feeling is here that "why are patients telling the specialists whats better for them?"
one of the things which bothers me about many of these things is the total lack of meta-data. I recall during my Masters research (water supply) in wondering why the consultants had chosen a rolling 11 year average for monthly rainfall expectations when the rainfall in the area was clearly seasonal and stochastic. In short their strategy blinded the water utility to the fact that droughts could occur.
a classic example of mushing up the data ... making it seem grand "ohh, one thousand four hundred and twenty years ... cough cough ... oh ok on average just a little bit under two years.
clearly not data from their study an average follow up of 20.7 months
well what do you know ... seeking answers best dug out of meta-data (that was lost) for some horizontal vs vertical analysis.
ok, I'm unclear here ... are they talking about patients in the study being high risk? Then this isn't really representative of younger healthy adults ...
ok ... so what were the age groups? I mean its implied here with two, three four reops there must be some under 40 patients....
I can't understand why data is not presented clearly, say in the style of the long term followup of my cohort (see a post here)
it seems to me like a lot of good data and research is wasted. I can only guess that people really don't want to know.
The dollars that are being poured into the new anti-coagulant adds for non-valve patients will give you some idea of the potential $$$ market that exists for such a drug. Remember that heart valve patients are only a tiny percentage of warfarin users. Kinda reminds me of the "furor" of the Lipitor, Crestor, etc. anti-cholesterol adds of a few years ago. Maybe a newer form of anti-coagulant for valvers will come from these newer drugs.....until then "take your warfarin as prescribed and test routinely".
ElectLive
Well-known member
Bioprosthetic you mean? Short term anticoagulation is common, at least procedural. Long term anticoagulation, though, is not standard, but in the currently targeted age group is fairly common due to other related factors.
This is simply NOT true. All the Percutaneous valves right now are TISSUE valves and for the most part do NOT require anticoagulants, some times they use a short time of anticoagulants right after they get the valve, but NO longterm anticoagulants is one of the Pluses for TAVI or other percutaneous valve replacements so to quote you the people who "WILL require anticoagulation therapy, now at an advanced age and when the real danger of stroke and bleeding events really matters" are the people who get a mechanical valve now when they are younger.. Also for the foreseeable future IF a mechanical valve does need replaced, they are NOT candidates for to get that valve replaced by cath and will need OHS.
According to Virchow's triad, factors predisposing to thrombus formation can be divided into endothelial, haemodynamic and haemostatic factors. (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1861363/) (http://www.ncbi.nlm.nih.gov/pubmed/9870192)
The hemodynamic properties of modern mechanical prostheses are superior to those of tissue valves because of the significantly more favourable relation between total prosthetic valve area and effective prosthetic valve orifice area, conditioned by design. (http://www.ncbi.nlm.nih.gov/pubmed/4096074, 1985!)
These are REALLY old articles, the 2nd one is from 1985 and most likely wasnt about any of the valves being used today.
I'm pretty sure the reason 30% of older bio valve patients are on aspirin, has nothing to do with their valve and more to do with many docs recommend aspirin for most older patients altho Im pretty sure the reason any of these people are on anticoagulants is to avoid clots caused by various conditions and not for other benefits
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