Severe Coronary Artery Disease - Prognosis

[Rich-B]

Posted By  CCF CARDIO MD - MTR on March 16, 1998 at 11:00:42:

In Reply to: Severe Coronary Artery Disease - Prognosis posted by Rich B. on March 08, 1998 at 02:33:15:

: Would you recommend only intensified medical treatment and a special diet for the following patient?:  A person in their late 50's who ten years ago had triple vessel disease with a normal EKG but an abnormal exercise EKG (depressed ST segment)and subsequent CABG(quadruple).  Several months after the operation was able to go 15 minutes, Bruce protocol, without any symptoms.  Now, ten years later, was able to go 10 minutes with only shin pain and again a normal EKG and an abnormal EKG during an exercise test.  A cardiac catheterization was performed with the following results: The saphenous vein grafts to the distal LAD and the mammary artery graft to the mid-left LAD were patent but there was subtotal occlusion of the left main coronary artery, total occlusion of the ostium of the LAD, and 95% stenosis of the first portion of the LAD just after a diagonal branch, and greater than 50% stenosis of the distal LAD between implants of the saphenous vein and the mammary artery.  There was subtotal occlusion at the origin of a small left circumflex, and 85% stenosis of the distal right coronary artery between the origins of the posterior descending and the posterior left ventricular branches.  There was 90% stenosis of a sequential saphenous vein graft to two branches of the distal RCA.  The LV ejection fraction ten years ago was about 70% (0.70) although there was mild anterolateral hypokinesis and is now estimated to be about 0.50.  This is a brief synopsis.  The patient experienced a mild "burning" sensation in his lungs about ten years ago and again just recently which led to the present tests.          

[CCF Cardio MD - MTR]

_
Dear Rich, thank you for your question.  The patient in question has complex coronary and
bypass graft anatomy but I'll try to summarize what I can ascertain from your question.
This patient has an occluded left coronary system and a distal high-grade stenosis of the
right coronary artery (RCA).  The LAD has multiple lesions, but with two patent grafts
to the mid and distal portions, there should be enough flow to prevent ischemia in the
anterior wall of the left ventricle.  The only area of the LAD that might be ischemic would
be the first diagonal since blood flow from the internal mammary graft (LIMA) would have
to go through a 95% lesion in retrograde fashion from the LIMA graft to reach this branch.
The circumflex (LCX) is described as small and is occluded at its origin.  You don't
describe a bypass graft to it although you do mention that this patient had a quadruple
bypass.  This territory is probably ischemic as well.  Finally, the vein graft to the
RCA is severely diseased and supplies two distal branches that probably supply the inferior
and posterior walls of the left ventricle.  Again, this territory is ischemic as well.
   Now, there are two main questions.  First, does this patient have ischemia that
localizes to the areas mentioned above.  I wonder if the stress test that was done included
perfusion imaging to localize which areas of the left ventricle are ischemic.  That
information is vital to determining how to proceed.  If this patient has previously had
a myocardial infarction, then some of the left ventricle may be scarred.  If scar is present
in the territories mentioned above, there would be no reason to proceed with repeat
revascularization.  A stress thallium/sestamibi would be a good test for these purposes.
In patients with compromised ejection fraction's from a large scar burden, a rubidium
PET scan is a good test to determine ischemia, scar, and hibernating myocardium that
could benefit from revascularization.  Second, how severe are the patient's symptoms.
You mention a symptom of "mild chest burning" but is the patient functionally limited
by this pain and how many tests/procedures is he willing to undergo to alleviate these
symptoms?
   From the available information, it appears that there are two options.  First, and
probably most reasonable, would be to perform angioplasty and stenting of the vein graft
to the RCA which sounds like could be accomplished.  The circumflex artery would be hard
to approach with angioplasty since two sequential sub-total occlusions of the left main
and the origin of the left circumflex would need to be opened.  This would be difficult and
there would a high rate of restenosis.  Second, redo CABG could be considered but with
the LAD grafts patent, CABG would be for a small circumflex and a RCA that would expose
the patient to more risk than with angioplasty.  Thus, I believe that percutaneous
revascularization to the vein graft to the RCA would be the best option here.  I doubt
that medical therapy and dieting, alone, would take care of this problem.  These treatment
options certainly should be continued long-term, in addition to revascularization.
I hope you find this information useful.  Please write back if you have further questions.
Information provided in the heart forum is for general purposes only.  Specific diagnoses
and therapies can only be provided by your physician.