Bleeding in Relation to Aortic Valve Stenosis

[Mimi__0__0]

  My father, age 86, recently was diagnosed with severe aortic valve stenosis and will need to undergo an aortic valve replacement.  During tests leading up to his surgery they have discovered he is anemic (rbc of 10) and have found occult blood in his stool from a rectal exam.  He now has to go for a colonoscopy before they can proceed with the heart surgery.
  He has been on Coumadin for about 3-4 weeks since he was also diagnosed with atrial fibrillation.
  Is it possible that the aortic valve problem itself could cause arterial problems that could lead to GI bleeding?  Can Coumadin alone cause bleeding or does it have to be in conjunction with a pre-existing condition such as a polyp or cancer?  Just wondered, as I am naturally now very nervous about the outcome of the colonoscopy and wonder if I am worrying needlessly.  He has no other GI symptoms and his stool habits have remained normal.
  Thanks for your help.

[CCF Cardio MD - MTR]

Dear Mimi, thank you for your question.  Aortic stenosis can be associated with
gastrointestinal bleeding from the colon.  Malformations of the blood vessels
in the mucosal layer of the colonic wall called AVM's are thought to be the cause
of this disorder.  However, the information published in the medical literature
is controversial regarding this association.  Some authors have noted an increase
in GI bleeding in patients with AS that is alleviated with valve replacement,while
others have not found the same association.  Coumadin is a blood thinner that is
used for atrial fibrillation to prevent clots from forming inside the heart.  While
someone is one coumadin, they are at risk for having GI bleeding from another
disorder that may be quiescent when the blood is not thinned.  Coumadin therefore
may "unmask" a condition like colonic polyps that otherwise may go unnoticed.
When occult blood is found in the stool, there is no blood evident on inspection
of the stool.  Occult blood is picked up with a simple bedside test.  A colonoscopy
is the best test for determining the cause of the occult blood in the stool. Coumadin
by itself shouldn't cause occult GI bleeding without having an underlying disorder.
Issues like these need to be investigated before undergoing valve replacement surgery
because patients need to be on large doses of blood thinners during surgery and
that may precipitate a large GI bleed if the underlying problem isn't dealt with.
Your father should stop his coumadin 3-4 days before the colonoscopy in case biopsies
are needed during the procedure.  I can't quote complications relating to
colonoscopy so I suggest that you talk with the gastroenterologist who will be
doing the colonoscopy regarding complications.  I hope you find this information
useful.
Information provided in the heart forum is for general purposes only.  Specific
diagnoses and therapies can only be provided by your physician.