Complementary Alternative Cardiovascular Medicine

192 Alternative Cardiovascular Medicine
EDTA chelation has also been used in patients with cerebrovascular
disease. The claims of efficacy with EDTA therapy in this population are
based on subjective clinical improvement and, in some studies, improved
cerebral perfusion or reduction in degree of carotid stenosis, as assessed
by noninvasive testing (6,10,12–18). However, the patient populations
were generally small. Most importantly, the studies were without appropriate
controls, and, in some, there was criticism of methodology. Particularly
in the older data, the observations were subjective and
descriptive. Thus, there are no well-designed randomized trials of EDTA
in the treatment of cerebrovascular disease.
Randomized Controlled Trials
There have been three interpretable, randomized trials of EDTA chelation
for patients with atherosclerotic vascular disease. A fourth trial,
the Pilot Trial to Assess Chelation Therapy (PACT), is currently ongoing.
Two prospective trials conducted by vascular surgeons in Denmark
and New Zealand have evaluated the use of EDTA in peripheral vascular
disease. In 1992, the Danish trial randomized 153 patients with stable
intermittent claudication to receive either 3.0 g EDTA or placebo (20,21).
The treatment regimen consisted of 20 infusions administered over 5 to
9 wk. The primary end-points were walking distance and ankle/brachial
indices. The changes observed in the pain-free and maximal walking
distances, measured on a treadmill, were similar in the two groups.
During the 3-mo (n = 149) and 6-mo (n = 123) follow-up period, no
long-term therapeutic effect of EDTA could be demonstrated. This trial
was criticized for the high dropout rate at 6 mo. Additionally, the blinding
protocol was violated, and the Danish Committee on Scientific Dishonesty
criticized various methodological study aspects (22).
In 1994, the New Zealand group randomized 32 patients and compared
EDTA with placebo in the treatment of stable intermittent claudication
(23). There were 32 patients recruited who had peripheral vascular
disease confirmed by angiography. Patients with diabeties were excluded,
and patients were required to stop smoking. The active infusion consisted
of 3.0 g of EDTA, 0.76 g magnesium chloride, and 0.84 g sodium bicarbonate
in normal saline. The placebo infusion was normal saline. There
were no significant differences reported in pain-free walking distance or
total walking distance when the EDTA-treated group was compared to
the placebo group. However, at 3 mo after treatment, resting anklebrachial
indices showed some improvement in the chelation group in
both legs, with a significant between-groups effect favoring chelation.
An extensive analysis of quality of life also was performed in the research
subjects, with mixed results. Although there were no differences in scales