Free radicals

[Troy__0]

Posted by Troy on June 15, 1999 at 13:54:50
Dear Sirs,
Within the last couple of years there has been much emphasis placed on the role of free radicals and the oxidization of LDL particles which then makes it easier for the endothelial cells to uptake these particles.  This has added a whole new dimension to the treatment of CAD and given much interest in the idea of antioxidant therapy with vitamins and various supplements.  One article I recently read (from the Univ of Florida Medical School) suggested the combination of a statin drug with an ACE inhibitor for the treatment of hyperlipidemia - stating the combination of the two will decrease the amounts of free radical oxidization of LDL and restore function to endothelial cells.  My question is this:  Given the now accepted role of oxidized LDL particles (resulting from free radical formation) in the initiation and progression of CAD - is chelation therapy still considered "voodoo" now that there is some scientific basis for it's actions (i.e. the reduction of formation of free radicals)?  It has been long known that EDTA therapy will reduce formation of these particles but only recently has the connection been made between free radicals/oxidized LDL/and CAD.  As far as I can tell, resistance to this treatment from the mainline medical community stems from the lack of multiple, large, double blinded studies along with a tangible scientific basis on which to rest.  But we fail to realize that only 20-25% of "accepted" medical treatments in all of medicine have ever had such studies to prove there effectiveness and many of the treatments we still don't have a "scientific basis" on why they work - we just know they do.
Sorry for the length of this.  I'm just interested in your position.
Troy


Posted by CCF CARDIO MD - JMF on June 15, 1999 at 16:21:01
Dear Troy,
Thank you for your well-stated review on antioxidants and atheroslerosis.  Unfortunately, no clinical trials of chelation therapy per se have been done.  In the meantime, there is ample epidemiologic and population case control studies as well as prospective cohort studies that indicate an inverse relationship between the clinical manifestations of coronary artery disese (disease) and the intake of certain antioxidant vitamins (The Cambridge Heart Antioxidant Study, the Physicians Health Study, and the Nurse's Health Study).  These studies have supported the "oxidative modification hypothesis of atherosclerosis, suggesting a central role for oxidative stress in the etiology of CAD.  At this point in time, randomized clinical trials have failed to show consistent benefit with beta carotene supplementaion but an apparent benefit with a-tocopherol.  Little is known about the role of chelation therapy on outcomes in coronary atherosclerosis.  Further trials are required to answer your important question.
In the meantime, i do recommend that patients with CAD take adequate supplementation with vitamins C, B and E.  At this point i do not routinely recommend chelation therapy, but in cases of very aggressive CAD have suggested it as an alternative treatment where other risk factor modification strategies have failed. I believe that we all must keep an open mind regarding the importance of antioxidants in CAD.
I hope this has been useful. I wish you the best of luck. Feel free to write back.
Information provided here is for general purposes only. Specific questions should be addressed to your own doctor. If you would like to make an appointment at the Cleveland Clinic Heart Center, please call 1-800-CCF-CARE or inquire online by using the Heart Center website at www.ccf.org/heartcenter. The Heart Center website contains a directory of the cardiology staff that can be used to select the physician best suited to address your cardiac problem.