AVR Porcine vs. Mechanical

[priscila__0]

  I'm 28 y/o and in need of an AVR due to leakage.  I have a gradient of 60mm.  I am trying to decide which valve to use.  I've done a fair amount of research on both, but I need some statistics. And I would like to ask about homograft valves.
  1.  I want to know about the risks/problems involved with taking coumadin for over 30 years. I haven't been able to find info on this. Are there any reports out on this?
  2.  What are the statistics on patients who have porcine valves that end up having to take coumadin (or daily aspirin because of A-Fib. troubles, thick blood, etc.)?  Is that even true? Please explain.
  3.  Do the homograft valves outlast the porcine valves?  I heard they're expectancy is 15 yrs or more.
  I was leaning towards the porcine valve because I thought there was no coumadin involved.  However, if there's a reasonably high percentage of people who have this valve and do need the coumadin, it would definately change my mind.  It defeats the purpose in my opinion.  Also, is there more risk involved with having another surgery (need in 10-15 yrs. for porcine) or going with the mech. valve and taking coumadin for 30 yrs.?
  Thank you in advance!
  priscilla

[CCF Cardio MD - MTR]

_
Dear Priscilla, thank you for your question.  You are facing a difficult decision
about what type of aortic valve is the best choice to use to replace your valve
that is damaged by aortic stenosis. First, I think you should look at my response
to a question by Susan S. on 6/16/98 about the same topic.  I list many references
there that you may find useful.  Other references that I've recently found are:
- Aortic valve homografts in adults: a clinical perspective.  ME Staab, et. al.
   Mayo Clinic Proceedings, volume 73, 1998, pgs. 231-238.
- Modern management of prosthetic valve anticoagulation.  DJ Tiede, et. al.
   Mayo Clinic Proceedings, volume 73, 1998, pgs. 665-680.
Second, I'll address your questions one by one.
1) The long-term risks of coumadin are hard to estimate but your risk of having
a significant bleeding complication would certainly be higher than without
coumadin.  Most randomized trials comparing the intensity of anticoagulation
for mechanical valves have found the rate of bleeding to be 2-5%.  Your long-term
risks of bleeding would be determined by the dose of coumadin, your risk of
falling and injuring yourself, and what type of valve you would have.
2) Patients with porcine valves usually do not take coumadin unless they have
another reason to do so like atrial fibrillation.  The review article I mention
above recommends that coumadin should be used for the first 3 weeks after a
porcine valve replacement, but that recomendation is controversial. I could not
find statistics on how many patients with porcine valves need coumadin, but
it's been my experience that very few patients who undergo porcine aortic valve
replacement need coumadin.
3) Homograft valves are cryopreserved specimens from cadavers that are thought
to last longer than porcine valves but long-term results from homograft valve
replacements are still forthcoming.  These valves are thought to be more durable
than porcine valves but firm data is not yet available to support this statement.
The article mentioned above on aortic valve homografts would have more detailed
information.
Overall, there are a number of issues you should take into consideration.  
If you are planning on becoming pregnant and having children in the future, then
you don't want to have a valve that requires coumadin because coumadin can harm
the fetus during the first trimester.  The article I mention on prosthetic valve
anticoagulation claims that the risk of birth defects at doses of coumadin
below 5 mg/day is minimal, I think there's no reason to take a chance with such
an important issue.  Also, if you lead an active lifestyle and you don't want to
have your activities limited by using coumadin (you would not be able to do
many sports that involve a chance of contact or falling), then a valve that
doesn't involve anticoagulation would be right for you.  A mechanical valve
has the greatest durability but involves coumadin.  A porcine valve doesn't
require coumadin but has a lifespan of 10-15 years.  A homograft probably has
a lifespan > 15 years and doesn't require coumadin.  Another option would be
the Ross procedure.  In this procedure, the pulmonic valve is switched to the
aortic position and a homograft is used to replace the pulmonic valve.  The
pulmonic valve in the aortic position and the homograft in the pulmonic position
are both thought to last longer than an aortic valve homograft.  Check out
prior questions in the heart forum and Frequently Asked Questions for more
information on the Ross Procedure (there's also a website on this procedure
but I don't know the URL).  The Ross Procedure or an aortic valve homograft
appear to be the best choices for you.  Neither valve may last for your entire
life but would allow you to be active and have children in your younger age.
A redo valve replacement surgery can be done with minimal risks and you may
have to face that in 15-20 yrs with one of these valves if they fail.  Our
cardiac surgeons at Cleveland Clinic are experts at valve replacement surgery
and would be happy to evaluate you if you would like to be seen here.  To
schedule an appointment, call 216-444-4470.  I hope you find this information
useful and please write back with any additional questions.
Information provided in the heart forum is for general purposes only.  Specific
diagnoses and therapies can only be provided by your physician.