Still trying to make a final decision - my first post

[normofthenorth]

This Q is maybe mostly for Bob = tobagotwo, but also for Lyn and everybody else:

The Hancock II "Gold Standard" article says the following in its intro (3rd paragraph):

The Hancock II used for AVR was designed to be implanted in a supraannular position.

I've also seen the discussion following the publication of a 2007 comparison of the hemodynamics of the CEP Magna & the Hancock II, which also suggests that it's maybe wrong to class the Hancock II with the older not supraannular (sub-annular?) valves, while categorizing the Magna with the newer supraannular valves. (On the other hand, the CEPM DOES seem to have better hemodynamics, both in that 2007 and in a more recent study from Ottawa that Lyn has linked -- though surgeons are clearly enlarging aortas MORE with the CEP & CEPM than with the Hancock II, for reasons I don't really understand.)

Does anybody REALLY understand this stuff? Can't say that I do.

 

[dtread]

Dan, I appreciate that you want the source for the statement that they have similar lifespan outcomes. It's a generally accepted statistic in the medical world. Sources for it have been posted in the forums a number of times (including by me), and can be found with a search. It's the basis for the more common use of the biological valves in younger patients. Of course it includes mortality statistics from reoperations, as well as mortality from warfarin use and blood clots, which are the achilles heel of mechanical valves.

Regarding Tissue vs Mechanical studies, what I found:

1. Very Long Term Very Long-Term Survival Implications of Heart Valve Replacement With Tissue Versus Mechanical Prostheses in Adults <60 Years of Age, by Marc Ruel, MD, MPH; Vincent Chan, MD; Pierre Bédard, MD; Alexander Kulik, MD; Ladislaus Ressler, MD; B. Khanh Lam, MD, MPH; Fraser D. Rubens, MD; William Goldstein, MD; Paul J. Hendry, MD; Roy G. Masters, MD; Thierry G. Mesana, MD, PhD, (Circulation. 2007;116:I-294 – I-300.), found at: http://circ.ahajournals.org/cgi/content/full/116/11_suppl/I-294
This study was discussed previously in this thread, and I believe it has little relevance today as most of the valves that were in the study are no longer manufactured. Additionally the anticoagulation methods used were substandard.

2. Peterseim DS, Cen YY, Cheruvu S, Landolfo K, Bashore TM, Lowe JE, Wolfe WG, Glower DD. Long-term outcome after biologic versus mechanical aortic valve replacement in 841 patients. J Thorac Cardiovasc Surg. 1999; 117: 890–897. Found at: http://jtcs.ctsnetjournals.org/cgi/...aeecca597934e10f25ee6e59&keytype2=tf_ipsecsha
This study was good in that it compared the St Jude bileaflet valve to the Carpentier-Edwards biological valve. However, the duration of the study was only ten years. With biological valves failing between 12 – 20 years, 10 years is not long enough to test the longevity of the biological valve. The study would need to run at least 15 years, if not 20 – 25 years to get more meaningful results. However, the study concluded: “Patients with an expected survival of less than 10 years (more than 65 years old, renal disease, lung disease, patients who are more than 60 years old), ejection fraction of less than 40%, or coronary disease would be reasonable candidates for aortic bioprostheses to avoid anticoagulation with an extremely low likelihood of aortic valve reoperation. Results tend to favor mechanical aortic valves in patients under age 65 years with a life expectancy of at least 10 years.”

3. Kulik A, Bedard P, Lam BK, Rubens FD, Hendry PJ, Masters RG, Mesana TG, Ruel M. Mechanical versus bioprosthetic valve replacement in middle-aged patients. Eur J Cardiothorac Surg. 2006; 30: 485–491. Found at: http://ejcts.ctsnetjournals.org/cgi...jkey=309213f927becc2a51b946c91d38def7149443b2
This seems to me to be the most relevant study that I’ve seen. It compared several mechanical versus biological valves and the duration was pretty good as the trial went from 1977 to 2002. Some of the highlights of the conclusions: “The data does not support lowering the usual cutoff for implantation of a tissue valve below the age of 65”, and “It appears that the use of a mechanical prosthesis is at least as good as, and possibly better, than that of a bioprosthesis in middle-aged patients. Therefore, a mechanical prosthesis likely remains a sound clinical choice for a middle-aged patient, unless there is a specific contraindication to the use of anticoagulation therapy.”

These findings favor mechanical valves to avoid the achilles heel of biological valves, which is of course the periodic reoperations. I would agree with the findings of the last two studies.

 

[Lynlw]

Regarding Tissue vs Mechanical studies, what I found:
3. Kulik A, Bedard P, Lam BK, Rubens FD, Hendry PJ, Masters RG, Mesana TG, Ruel M. Mechanical versus bioprosthetic valve replacement in middle-aged patients. Eur J Cardiothorac Surg. 2006; 30: 485–491. Found at: http://ejcts.ctsnetjournals.org/cgi...jkey=309213f927becc2a51b946c91d38def7149443b2
This seems to me to be the most relevant study that I’ve seen. It compared several mechanical versus biological valves and the duration was pretty good as the trial went from 1977 to 2002. Some of the highlights of the conclusions: “The data does not support lowering the usual cutoff for implantation of a tissue valve below the age of 65”, and “It appears that the use of a mechanical prosthesis is at least as good as, and possibly better, than that of a bioprosthesis in middle-aged patients. Therefore, a mechanical prosthesis likely remains a sound clinical choice for a middle-aged patient, unless there is a specific contraindication to the use of anticoagulation therapy.”

These findings favor mechanical valves to avoid the achilles heel of biological valves, which is of course the periodic reoperations. I would agree with the findings of the last two studies.

True but that study also showed
3.3 Thromboembolism
3.3.1 Stroke
The 10-year freedom from late postoperative stroke was 90.0 ± 2.7% for mechanical AVR patients, 97.6 ± 1.7% for bioprosthetic AVR patients, 87.9 ± 4.1% for mechanical MVR patients, and 91.1 ± 5.0% for bioprosthetic MVR patients. No strokes occurred in the 35 DVR patients. There was no difference in the stroke risk between mechanical and bioprosthetic valves in either implant position.
3.3.2 All thromboembolism
The 10-year freedom from any postoperative thromboembolic event (stroke, transient ischemic attack, or peripheral embolus) was 79.2 ± 3.9% for mechanical AVR patients, 97.6 ± 1.7% for bioprosthetic AVR patients, 69.0 ± 7.5% for mechanical MVR patients, and 87.6 ± 6.0% for bioprosthetic MVR patients. There were three events in the mechanical DVR group (10-year freedom: 91.1 ± 4.9%), and there was no thromboembolism in the one tissue DVR patient. On multivariate testing, there was a tendency towards more thromboembolic events amongst AVR patients with a history of smoking (HR: 2.0; CI 0.9, 4.6; P = 0.10). Following MVR, independent risk factors for a thromboembolic event included the presence of a mechanical valve (HR: 4.1; CI 1.3, 12.7; P = 0.01) and female gender (HR: 2.4; CI 1.1, 5.3; P = 0.03). Preoperative left atrial diameter, preoperative NYHA class, LV grade and year of surgery had no significant effect on thromboembolism after AVR or MVR

Which is why valve choice is such a personal decision, Which would you rather live with

As the rest of the paragraph you quoted pointed out

"Nonetheless, we believe that decisions regarding the choice of prosthesis need to be individualized and discussed between the patient and the treatment team. Factors that must be taken into account include the presence of comorbidities affecting long-term survival, the risks and inconvenience of anticoagulation, the risks associated with reoperation, lifestyle issues, and patient personal preference. In the future, newer bioprostheses more resistant to structural valve deterioration, less thrombogenic mechanical prostheses, and newer forms of anticoagulation will mandate a re-exploration of the issue of the ideal valve choice in the middle-aged patient."


Isn't it great we live in a time that there are so many good choices and people can make up their mind which they personally rather live with? It will be interesting to watch the next few years what things look like then.

 

[ALCapshaw2]

There are a larger number of mechanical valves on the market. They all are engineered to last beyond severl lifetimes' usage, and are usually not replaced for wearing out or failures on the valve's part. The most common are St. Jude Medical Regents and Masters series (the regent is the most common mechanical valve by far), the ATS Open Pivot® Heart Valve, the On-X Life Technologies On-X valve, and the Sorin Carbomedics Top Hat (in the US, with a number of different international lines). These are all manufactured from pyrolytic carbon over a titanium skeleton, but have differences in hinge pivot and flow surfaces design and in their carbon manufacturing and formulations. The commonly used ones are bileaflet design, but there may be one tilting disk still on the market (tilting disk may work slightly better for mitral valve use, according to at least one study). The St. Jude has a 30+ year useful lifespan track record so far and counting. The main reasons for replacement are interfering pannus (scar tissue), blood clots on or under the valve, vegetation from infective endocarditis, or placement issues (rubbing). All these mechanical valves are reliable. Perhaps the most advanced currently on the market is the On-X, which has a carbon formulation that does not contain silicon (causes bloodflow drag) and has an anti-pannus design, intended to reduce the possibility of scar tissue interfering with its leaflets.

Bob - Where did you get the impression that the St. Jude Regent is the most common mechanical valve by far?

FYI, the Regent was introduced shortly AFTER the On-X came to market.
The St. Jude MASTER's Series Valves are the ones with the 30+ year track record and counting.

FYI, the SORIN Mechanical Valve (produced in Italy) is the ONLY mechanical valve that uses a titanium base.
There are reports of pieces of the coating breaking off from this valve.

NONE of the Bi-Leaflet Mechanical Valves manufactured in the USA (ATS, Carbomedics, On-X, St. Jude) use a titanium base.

The Last of the Tilting Disk Mechanical Valves were manufactured by Medtronic-Hall.
They are NO LONGER in production.

'AL Capshaw'

 

[normofthenorth]

Lyn, those "freedom from" (stroke & total thromboembolisms) numbers seem shockingly one-sided, in favor of tissue valves. I'm confused about seeing those numbers in an article that seems to favor mechanical valves.

Here's what you quoted:

3.3.1 Stroke
The 10-year freedom from late postoperative stroke was 90.0 ± 2.7% for mechanical AVR patients, 97.6 ± 1.7% for bioprosthetic AVR patients

And here's what it means "inverted" to be (IMHO) more meaningful:
For mechanical AVR patients, 10% (± 2.7%) experienced at least one late postoperative stroke in the first 10 years post-op. For tissue AVR patients, 2.4% (± 1.7%) experienced at least one late postoperative stroke in the first 10 years post-op.
For the corresponding risks of any kind of thromboembolic event, you then quoted

The 10-year freedom from any postoperative thromboembolic event (stroke, transient ischemic attack, or peripheral embolus) was 79.2 ± 3.9% for mechanical AVR patients, 97.6 ± 1.7% for bioprosthetic AVR patients.

And here's what it means "inverted" to be (IMHO) more meaningful:
For mechanical AVR patients, 30.8% (± 3.9%) experienced at least one postoperative thromboembolic event (stroke, transient ischemic attack, or peripheral embolus) in the first 10 years post-op. For tissue AVR patients, 2.4% (± 1.7%) experienced at least one postoperative thromboembolic event (stroke, transient ischemic attack, or peripheral embolus) in the first 10 years post-op.
[All I've done is subtract the "freedom from" percentage from 100% to get the percentage of patients who experienced at least one of those events.]

The 4-fold difference between a 2.4% chance of a stroke in 10 years and a 10% chance seems huge to me, and the THIRTEEN-FOLD difference between a 2.4% chance of any thromboembolic event and a 30.8% chance seems even huger! [The fact that the 2.4% and the 97.6% are identical for strokes and total thromboembolic events looks funny, but probably means that the tissue-valvers didn't actually experience any non-stroke thromboembolic events, unless somebody copied something wrong. Does that explanation seem plausible, Lyn?]

I assume the quoted stats are NOT for middle-agers, but for all patients, many of whom were older. True?

It still seems strange to me, that a study that finds the risks of mechanical valves so obviously scary-high should recommend them. . .

 

[normofthenorth]

OK, I've since started looking at that study (from Ottawa), and the shockingly one-sided numbers for strokes and clots are basically balanced by similarly one-sided numbers for re-ops etc.

Their "MAPE" composite measure of bad outcomes unfortunately includes ReOperation as one trigger, rather than the more meaningful Structural Valve Deterioration. (The latter includes people who "need" a valve replacement, but aren't candidates for surgery, so they don't GET one.) The resultant bias would probably work in favor of bioprosthetic (tissue) valves, I think.

 

[normofthenorth]

And now that I've read it through, I find that

1. They say the data "suggest" that middle-aged tissue valvers have higher rates of "MAPE" (major adverse events) than mechanical-valvers, but their statistical efforts to prove that all failed! They BELIEVE that subsequent studies with longer follow-up will prove that it's true, but this study does not.
2. They point out the recent stats on the longevity of the CEP (cow) tissue valve, and mention how much BETTER those results are than the tissue-valve results in this study. They discuss some reasons for the huge difference.
3. They naturally do not discuss the EVEN BETTER results in the brand-new "gold standard" study of the durability of the Medtronics Hancock II (pig) tissue valve, because that was published in 2010 and this study was from 2006. But both of those studies suggest that the Ottawa tissue-valve results aren't up to today's standards, at least with those two popular and durable valves.
4. I don't understand how the burden of proof works in their "At present, these data do not support lowering the usual cutoff for implantation of a tissue valve below the age of 65." Is there a "cutoff" that now suggests that NOBODY below 65 should get a tissue valve?? First I heard. Does the "cutoff" prevent anybody older than 65 from getting a mechanical valve?? This study basically proves that among middle-aged (50-65) AVR and MVR recipients, there's NO statistically-significant difference in longevity or frequency of MAPE based on the choice of a mechanical or a tissue valve. So it sounds like middle-agers are still faced with a difficult choice, without any clear guidance from this data. But that quoted sentence seems to suggest something different, doesn't it??
   
   
   
   

 

[dtread]

I don't understand how the burden of proof works in their "At present, these data do not support lowering the usual cutoff for implantation of a tissue valve below the age of 65." Is there a "cutoff" that now suggests that NOBODY below 65 should get a tissue valve?? First I heard. Does the "cutoff" prevent anybody older than 65 from getting a mechanical valve?? This study basically proves that among middle-aged (50-65) AVR and MVR recipients, there's NO statistically-significant difference in longevity or frequency of MAPE based on the choice of a mechanical or a tissue valve. So it sounds like middle-agers are still faced with a difficult choice, without any clear guidance from this data. But that quoted sentence seems to suggest something different, doesn't it??[/LIST]

Norm, I think what you have to do is think back to the history of heart valves. Originally the first artificial heart valves were all mechanical (ball and cage for the most part). Then later on tissue valves were introduced, but it was noted that they failed after some period of time. So, tissue valves were usually implanted in folks that were old; i.e., folks that were not expected to outlive the valve. So the "cutoff" of 65 was established. More recently the procedures for open heart surgery have improved so that the percentage of folks that die from the surgery is a lot less than it used to be. So some folks are promoting the concept of getting a tissue valve in middle age, thus basically planning a second surgery (before they've even had the first surgery). What the stats don't show is those folks that opted not to get the reoperation, and thus basically lasted as long as their valve lasted. Don't forget - the surgery is a killer. Particularly when you're older. The recovery is a real bear. I was in good shape and it almost killed me. I ended up going to ICU five days after surgery because of heart block (caused no doubt by the surgery), and ended up having to get a pacemaker, in addition to the heart valve. It took me about a year to get back to near 100% of what I was pre-op. I guess its okay if you're a sedentary person and don't exercise. The operation is going to slow you up but if you were sedentary to begin with if the surgery doesn't kill you I guess you'll make out. But if you're interested in any kind of athletics or physical conditioning the surgery is really going to knock the wind out of your sails, for quite a long time. And don't forget the medical expenses, etc., with valve replacement surgery easily costing $100K or more.

 

[Lynlw]

OK, I've since started looking at that study (from Ottawa), and the shockingly one-sided numbers for strokes and clots are basically balanced by similarly one-sided numbers for re-ops etc.
Their "MAPE" composite measure of bad outcomes unfortunately includes ReOperation as one trigger, rather than the more meaningful Structural Valve Deterioration. (The latter includes people who "need" a valve replacement, but aren't candidates for surgery, so they don't GET one.) The resultant bias would probably work in favor of bioprosthetic (tissue) valves, I think.

Yes I said in the first post (#16) about that study that I didn't like it much because it went by MAPE, however I personally think that would have the bias go the other way, since the majority of "events" for a tissue valve is a REOP (which the vast majority of people do fine with) compared to the majority of "event" the Mech is mainly strokes (Clot or bleeding), clots ect. since "A composite outcome of major adverse prosthesis-related events (MAPE) was defined as the occurrence of "reoperation, endocarditis, major bleeding, or thromboembolism"

I personally don't think they really are equal.
Maybe IF they compared a "bad" out come from the REDO against the stroke, or hemorrage it would be more meaningful to me at least. Especially since for this study the bleeds or strokes were major ones.

"Prosthesis-related complications were recorded according to the Guidelines for Reporting Morbidity and Mortality after Cardiac Valvular Operations [5]. Briefly, stroke was defined as the presence of a neurological deficit lasting more than three weeks and was confirmed with computerized tomography of the head [4,5]. Bleeding events were classified as major if they required surgery, hospital admission, blood transfusion, were intracranial in location, or caused death. Reoperation was defined as any operation that repaired, altered, or replaced a previously operated valve [3,5]."

I personally don't worry about the exact data of 1 or 2 studies especially since there are only a couple comparing the valves , and there are tons of studies studying each valve by themselves, which I am sure many people (patients and doctors) take them into consideration to when comparing the different valve choices. I read a few studies .. (well I have lots of time so maybe more than a few) and see what the majority show..IF there is a majority. Not to mention as was pointed out several times, by the time you do a study and follow that set of patients for years and write up the study ect, already it is most likely outdated since newer and improved things have come along.
Really to learn the most recent findings, opinions ect, I go more by talking doctors and watching the webcasts from the different heart doctors conferences, since not only is that where many of the other doctors learn the up to date news, but they also talk about current trials, that may not be written up for a few more years. Some of them are pretty interesting when they have the Q&A and discussions after the sessions.

The ONLY reason I even posted the studies comparing valves , was because people wanted to know why, or doubted "Your lifespan expectation is statistically the same for either choice, as the dangers of blood clots and anticoagulation with mechanical valves seem to balance against the dangers of reoperations with tissue valves over time." So I posted a few of the most recent studies showing that. Since IMO I think that is the point someone choosing a valve is considerring.

FWIW since you are going over the posted studies

I went to read this study Dan wrote about (in post #22)
"2. Peterseim DS, Cen YY, Cheruvu S, Landolfo K, Bashore TM, Lowe JE, Wolfe WG, Glower DD. Long-term outcome after biologic versus mechanical aortic valve replacement in 841 patients. J Thorac Cardiovasc Surg. 1999; 117: 890–897. Found at: http://jtcs.ctsnetjournals.org/cgi/c...e2=tf_ipsecsha
This study was good in that it compared the St Jude bileaflet valve to the Carpentier-Edwards biological valve. However, the duration of the study was only ten years. With biological valves failing between 12 – 20 years, 10 years is not long enough to test the longevity of the biological valve. The study would need to run at least 15 years, if not 20 – 25 years to get more meaningful results. However, the study concluded: “Patients with an expected survival of less than 10 years (more than 65 years old, renal disease, lung disease, patients who are more than 60 years old), ejection fraction of less than 40%, or coronary disease would be reasonable candidates for aortic bioprostheses to avoid anticoagulation with an extremely low likelihood of aortic valve reoperation. Results tend to favor mechanical aortic valves in patients under age 65 years with a life expectancy of at least 10 years.”

but I noticed it is the CE PIG valve not the Bovine pericardial perimount.

"From 1976 to 1996, 1676 patients underwent aortic valve replacement at Duke University Medical Center. To obtain a more homogeneous population, we excluded patients undergoing a concurrent operation for placement of another valve, patients aged less than 18 years, patients receiving valves sized less than 19 mm, and patients with a previous sternotomy. To further improve population homogeneity and to eliminate prostheses that are now less used, we also excluded 489 patients who by surgeon preference received aortic homografts or prostheses used in small numbers. The resultant study population consisted of all 841 patients undergoing isolated, first-time aortic valve replacement with the Carpentier-Edwards (CE) standard porcine prosthesis (n = 429; model 2625; Baxter Healthcare Corp, Irvine, Calif) or the St Jude Medical (SJ) prosthesis

I know the centers that did these studies are taking part in the percutaneous valve replacement trials, so I wonder what their thoughts would be now, since you can't have a mechanical valve replaced in the cath lab- at least as they are being done now.
It will be interesting to see what happens the next decade

 

[Lily]

I am scheduled for surgery jan 17th and still trying to decide on non stinted - or stinted or ross procedure- i must make final decision by monday- non stinted may qualify for min invasive. Any one with advice is welcome- My doctors left me the options without blood thinners- and was not pushy about the Ross- due to me being 52 - even though he teaches the procedure widely- so now my time to decide has come. ANY HELP APPRECIATED !!

Welcome to the site. We all come into these heart surgeries with unique life experiences and then we all have unique life experiences from or because of the surgeries. While I personally thought my heart surgeries and recoveries weren't particularly easy, to me they have been a wonderful opportunity to extend my happy life. May it go so well for you too. Best wishes

BTW dtread (Dan), I'd never looked at your signature links before this evening and previously I had erroneously thought they were videos of your personal medical experience, because of the way you have them listed. Is it all music that is near and dear to your heart?

 

[normofthenorth]

Norm, I think what you have to do is think back to the history of heart valves. Originally the first artificial heart valves were all mechanical (ball and cage for the most part). Then later on tissue valves were introduced, but it was noted that they failed after some period of time. So, tissue valves were usually implanted in folks that were old; i.e., folks that were not expected to outlive the valve. So the "cutoff" of 65 was established.

Established by whom? Is this somebody's rough rule of thumb? Like a national Heart Association's? If you've got some documentation, I'm game for it, and also any indication of who's "cut off" from what.

More recently the procedures for open heart surgery have improved so that the percentage of folks that die from the surgery is a lot less than it used to be. So some folks are promoting the concept of getting a tissue valve in middle age, thus basically planning a second surgery (before they've even had the first surgery). What the stats don't show is those folks that opted not to get the reoperation, and thus basically lasted as long as their valve lasted.

Since the mortality stats include EVERYBODY, I think that last rant has no basis, right? There are a few patients who might have had "SVD" but not been candidates for re-op, so they wouldn't show up in their "MAPE", and I've already complained about that. But as Lyn says, the "MAPE" also treats serious strokes as somehow equivalent to a routine, no-bumps re-op to replace one tissue valve with another, which also seems nuts.

Don't forget - the surgery is a killer. Particularly when you're older. The recovery is a real bear. I was in good shape and it almost killed me. I ended up going to ICU five days after surgery because of heart block (caused no doubt by the surgery), and ended up having to get a pacemaker, in addition to the heart valve.

There are outliers in all statistics, but the general stats on mortality and morbidity from OHS, including re-ops, are remarkably good. I guess I was more likely to die on Dec. 1 than on any other day last year, but the difference wasn't all that huge.

It took me about a year to get back to near 100% of what I was pre-op. I guess its okay if you're a sedentary person and don't exercise. The operation is going to slow you up but if you were sedentary to begin with if the surgery doesn't kill you I guess you'll make out. But if you're interested in any kind of athletics or physical conditioning the surgery is really going to knock the wind out of your sails, for quite a long time. And don't forget the medical expenses, etc., with valve replacement surgery easily costing $100K or more.

The expenses of re-ops are clearly significant, and may NOT be balanced by the costs of the complications of mechanical valves, even if the latter balance them out in terms of life expectancy. Canada might be the perfect country to do that kind of analysis, but I haven't seen it done anywhere. And heart surgery does seem to take some time to recover from -- though I'm still planning on skiing a week in Whistler in less than a month (8+ weeks post-op), and I feel about ready to start bicycling (gently) now, just under 5 weeks post-op. I agree that if you were essentially symptom-free pre-op (as I was), then you'll be in worse shape for several (or even many) months post-op than you were before. Short-term pain for long-term gain, yes it IS a nuisance having a fatal but reparable heart-valve problem!

Your rhetorical "if the surgery doesn't kill you" flourishes don't seem to fit with surgery that has a ~1% mortality rate, presumably concentrated at the edge of the patient population that is ultra-high-risk going into the surgery (i.e., not you or me, the first time or maybe even the second).

Getting back to the Ottawa 2006 study that you're so fond of, they suggest that:

• SOMEBODY established a "cutoff" between the two basic kinds of valves, at 65 years of age. As in (I guess) "everybody >65 should get a tissue valve, and everybody <65 should get a mechanical valve".
• Then they noticed that more and more patients and cardiologists and surgeons were choosing tissue valves even though the patient was YOUNGER than 65 -- in violation of this so-called "cutoff".
• So they compared their AVR patients between 50 and 65 years old, to see if the choice of valve had a stat-significant impact on their life expectancy OR if it was a significant independent indicator of survival.
• It turned out to be NEITHER, though some of the statistics LEAN in the direction they imagined the data would go.
• In effect, they proved that 50-65-year-olds should NOT base their choice of valve type (tissue vs. mech) on any expectation that they'll live longer with a mech valve, because the data say it's not so.
• And their bottom line: The study suggests that it would be wrong to move the "cutoff" between the two valve types down below 65 years of age(!).
• WTF?? Is it me, or is it stupid in here? Either I'm missing something important -- like the official memo with the 65-year-old "cutoff" -- or this really sounds like an ultra-weak argument built on the quicksand of data that are NOT statistically significant after all!
• When I was at MIT, they used to say that it was great to have a hypothesis that pigs fly, but only if you proved that they DID! If you just proved that they did NOT, then you won't get a Ph.D. or a promotion for that "discovery". These authors entered a world where middle-aged patients are treating valve choice as if it's a "flip of the coin" from the POV of longevity, and they essentially proved that the popular assumption is correct -- pigs DON'T fly.

 

[Lynlw]

Norm for at least the past decade (and longer) the general rule of thumb, has been tissue over 65 and mechanical under 65. thei also is in the AHA and European guidelines for valve patients. How ever it is not something that has ever been "mandatory" set in stone, but for the most part up until the past 5-10 or so year, people pretty much followed them.

Recently as the tissue valves started lasting longer AND the risks of reops have improved, more people were choosing tissue at younger ages to avoid coumadin(which is part of the reason the % of tissue valves used in the last 5 years went up and mech down, the other reason fof course is many older people people with comorbidities that would not have been surgical candidates before because the surgical risk,now can have surgery and they get tissue)

Here is an 2008 article discussing the most recent guidelines http://circ.ahajournals.org/cgi/content/full/117/2/253 (with the guidelines in the footnotes but they were too long for me to pick out quotes for you) it also has a pretty good algorithm of which valve and discusses a few studies. This article points out that "In distinction to earlier guidelines, both the 2006 ACC/AHA guidelines7 and the 2007 ESC guidelines8 also make allowance (class IIa and class I, respectively) for preference of the informed patient in decisions involving prosthesis selection"

it also mentions "There are trends in the United States and Europe toward the increasing use of tissue rather than mechanical valves and toward the use of bioprostheses in progressively younger patients.7,8,11 These trends are supported by data showing that advances in tissue fixation and anticalcification treatment have resulted in current-generation bioprostheses that have superior durability compared with the first-generation porcine valves used in the 2 randomized trials performed in the late 1970s. .......In addition, advances in myocardial protection and cardiac surgical techniques have led to lower risks at reoperation, making the prospect of redo valve surgery less onerous"

the conclusion says
"Ideally, it would be desirable to have access to long-term outcome data for current-generation tissue and mechanical prostheses studied in large, multicenter, randomized clinical trials. However, large-scale randomized trials are unlikely to be performed, and if they were, pertinent clinical data would be available only after 15 to 20 years. By the time that long-term data became available, newer prostheses likely would have supplanted those in use today, and as is the case with the historic VA5 and Edinburgh4 heart valve trials, data would be obsolete before they were available.

Because of this paradox, the practitioner is forced to make informed clinical recommendations based on incomplete data, including data extrapolated from the historic randomized controlled trials and data from more recent nonrandomized studies. The ACC/AHA guidelines7 and ESC guidelines8 provide a structure for decision making. However, without compelling data from pertinent large-scale, long-term trials, decisions will and should remain influenced by experience and expertise. This is not to say that data from randomized clinical trials would not be helpful but rather that, in the absence of such trials, the clinician must guide patients in making an informed choice that relies on available data and is appropriate for the individual patient."

 

[normofthenorth]

Lyn, that's extremely helpful, as always!

 

[tobagotwo]

Al, I apologize. I don't know why I put the Regent in the followup sentence. I confused them in my head when I wrote it, and I didn't go back and recheck it. I should have.

I was also going to expand the line about the way the mechanical valves are made, but I somehow never got back to the sentence and redid it. Lyn and Norm also picked up errors in the text. I also said Hancock II, when I intended Hancock.

It was late, and I was afraid if I left it for the next day, it would be missing. I should've saved it in Word and reposted it when I had more time. I wish I had.

As a note, I am going to go back and correct theese issues in the post, in case someone refers to it later for information.

thank you,

 

[Lily]

Reading some of the comments got me to thinking/wondering and I eventually looked at the latest Wiki info on valves which offered some interesting details on valve choice in general that many might find to be beneficial information: http://en.wikipedia.org/wiki/Artificial_heart_valve

There was a link at the bottom of the page to the Mayo clinic (that didn't work for me). But anyway, regarding the "history of heart valves," I "think" that cadaver and animal valve replacements came before mechanical valve replacements were "invented," though please correct me if I'm wrong.

 

[dtread]

Norm, I think Lynlw answered most of your questions. Yes, the cutoff of 65 was basically established due to the fact that the tissue valves are more suited to elderly folks. If you implant a tissue valve in somebody that might be expected to live longer than a valve lasts, then its likely that the reop surgery will kill them. So that is how that came to be, like Lynlw says. It sounds like you had a relatively uncomplicated surgery and your recovery is going well. But there are a lot of folks on this website that can testify to "roadbumps" or setbacks in their recovery. Then there are those that didn't make it that can no longer post on this website. Also, I would caution you to not push too hard on your workouts in the early weeks/months. You're not going out for the Olympics and you don't want to have any setbacks due to pushing it too hard. Better to err on the side of caution. You might also want to check out www.cardiacathletes.org

Lily, believe the Hufnagel mechanical valve was the first. At one time I suggested that we establish a history section on the site but it never was accepted/implemented. There is a lot of heart valve history information on the web though; you just have to search for it. You have to read Wikipedia with some degree of caution. Anyone can post information to Wikipedia and you need to verify the sources; i.e., it is not all ironclad truth on Wikipedia. Also, your question regarding the links in my signature reflect a musical version of my whole AVR experience; from when I found out the time had come to go for the operation, to the operation itself, then to the hospitalization, and finally to recovery, which was a long, hard journey. And yes, those songs are all pretty much favorites of mine, but they now have special meaning to me because I now relate them to the AVR.

 

[OldManEmu]

Dan
I have attached a copy of a Carbomedics mechanical valve history poster. This may be of interest to you.

 

[normofthenorth]

Norm, I think Lynlw answered most of your questions. Yes, the cutoff of 65 was basically established due to the fact that the tissue valves are more suited to elderly folks. If you implant a tissue valve in somebody that might be expected to live longer than a valve lasts, then its likely that the reop surgery will kill them. So that is how that came to be, like Lynlw says. It sounds like you had a relatively uncomplicated surgery and your recovery is going well. But there are a lot of folks on this website that can testify to "roadbumps" or setbacks in their recovery. Then there are those that didn't make it that can no longer post on this website. Also, I would caution you to not push too hard on your workouts in the early weeks/months. You're not going out for the Olympics and you don't want to have any setbacks due to pushing it too hard. Better to err on the side of caution. You might also want to check out www.cardiacathletes.org

Dan, again, I'm having trouble squaring the statistical data with your alarmist rhetoric. First-time valve replacement OHS has a mortality rate of around 1%, including a bunch of high-risk patients who are just barely candidates for the surgery. Second-time re-ops may have twice that mortality rate these days, maybe 2%. (I think I've seen some relatively modern numbers, but I'm not sure. Got any?)

None of that is remotely compatible with your statements, like "it's likely that the reop surgery will kill them"(!) or "Then there are those that didn't make it that can no longer post on this website." Do you usually characterize a 2% probability as "likely", or just in this context? (If it's the former, then let's play poker some time! )

I've had AVR OHS (though admittedly relatively "bump-free"), and I know some people who've had strokes. If I had to choose between those two experiences, I'd take the re-op.

Norm

 

[dtread]

Dan, again, I'm having trouble squaring the statistical data with your alarmist rhetoric. First-time valve replacement OHS has a mortality rate of around 1%, including a bunch of high-risk patients who are just barely candidates for the surgery. Second-time re-ops may have twice that mortality rate these days, maybe 2%. (I think I've seen some relatively modern numbers, but I'm not sure. Got any?)

None of that is remotely compatible with your statements, like "it's likely that the reop surgery will kill them"(!) or "Then there are those that didn't make it that can no longer post on this website." Do you usually characterize a 2% probability as "likely", or just in this context? (If it's the former, then let's play poker some time! )

I've had AVR OHS (though admittedly relatively "bump-free"), and I know some people who've had strokes. If I had to choose between those two experiences, I'd take the re-op.

Norm

Norm:

Very Long Term Very Long-Term Survival Implications of Heart Valve Replacement With Tissue Versus Mechanical Prostheses in Adults <60 Years of Age, by Marc Ruel, MD, MPH; Vincent Chan, MD; Pierre Bédard, MD; Alexander Kulik, MD; Ladislaus Ressler, MD; B. Khanh Lam, MD, MPH; Fraser D. Rubens, MD; William Goldstein, MD; Paul J. Hendry, MD; Roy G. Masters, MD; Thierry G. Mesana, MD, PhD, (Circulation. 2007;116:I-294 – I-300.), found at: http://circ.ahajournals.org/cgi/content/full/116/11_suppl/I-294 Quote: “Valve reoperation, often for prostheses that are no longer commercially available, occurred in 89% and 84% of patients by 20 years after tissue aortic and mitral valve replacement, respectively, and was associated with a mortality of 4.3%.”

This website has summarizes cardiac risk indexes:
http://depts.washington.edu/gim/clinical/MCSSyllabus/Cardiac Assess.pdf
Note that “over age 70” adds five points, critical aortic stenosis adds 20 points, and poor general medical condition adds five points to put the patient at or near “high risk”. Reoperations involve working around scar tissue, which is more difficult and adds more risk. Add in all the time on the heart lung machine and the pumphead effect, in addition to the other downsides and risks of the surgery, not to mention the protracted recovery period (and the expense!).

The fact is that if someone needs to get a reoperation and they are elderly and/or in poor health, the risk is significantly higher than for a younger, first time patient. That is why tissue valves historically have been largely reserved for elderly patients that would not be expected to outlive the valve. Because if you put a tissue valve in a person that is younger, the odds are that they will outlive the valve and have to undergo a reoperation. When that time comes, their risk is significantly higher than it was for the first operation. Although there are probably not any statistics kept on it, I’ll bet that there are a lot of folks that forgo having a reoperation when the time comes simply because it is too traumatic or too likely to kill them.

I do not know where you got the 1% and 2% figures and believe that they are too low. Perhaps someone else on the forum can dig something up. When I get time I’ll do some digging around the web. I do know that statistics don’t mean much if you are one of the folks that doesn’t make it.

OldManEmu: thanks for the heart valve history poster; very nice. I'd seen it before and already have a copy saved on my hard drive but I bet there are a lot of folks on the site who have never seen it.

 

[Lily]

First implanted/replaced heart valves?

First implanted/replaced heart valves?

...I "think" that cadaver and animal valve replacements came before mechanical valve replacements were "invented," though please correct me if I'm wrong.

I'm still not sure what the official history is. I made quite a few different searches on this and found several different articles, some claiming that a few different surgeons were each the first to implant "artificial" valves, as opposed to what we now refer to as tissue valves. Possibly a key to explain whether those various claims [as to first artificial valve replacement surgery] may be contradictory is whether or not those valves were implanted with relative success; sadly many of them weren't. The earliest valve surgeries from the 20th century may have been attempts at mitral repairs, if the information I found is correct.

I also found some articles that said this, though without providing sources: "Replacement of diseased valves did not take place until 1962, when the first successful biological valves were invented using human tissue from a donor. Ball valves were the first type of mechanical valves and were developed around the same time."