November 2, 2004
Starkweather, B.S. and Asher Kimchi M.D.
Athens, Greece –
Ascorbic acid was found to decrease the incidence of
contrast-mediated nephropathy (CMN) in patients with renal
insufficiency undergoing percutaneous coronary angiography.
Published in the November 2, 2004 issue of Circulation,
investigators Konstantinos Sparias, MD, et al, from the Onassis
Cardiac Surgery Centre in Athens, Greece, enrolled 238 patients
in a randomized, double-blind, placebo-controlled trial that
tested the efficacy of ascorbic acid in preventing CMN in
coronary angiography patients with a baseline serum creatinine
concentration of >1.2 ml/dL.
Ascorbic acid has a well established history as a safe dietary
supplement in humans, and based on previous trials of the
antioxidant acetylcysteine, the possibility of using ascorbic
acid as a prophylatic treatment for CMN was explored.
Patients undergoing nonemergent coronary angiography or
intervention at the Onassis Cardiac Surgery Centre in Athens,
Greece, who had a baseline serum creatinine concentration of
>1.2 ml/dL within three months prior to the procedure were
included in the study.
randomly assigned to receive either 3 g of ascorbic acid via
chewable tablet or placebo at least 2 hours before the
procedure, followed by 2 g ascorbic acid or placebo the night
and morning after the procedure.
creatinine concentration was measured from a sample drawn at the
time of randomization, and follow-up levels were drawn at 2 and
5 days post-procedure. CMN was defined as an absolute rise in
serum creatinine concentration of at least 0.5mg/dL or a
relative rise of at least 25% from baseline.
completed the study out of the 238 patients enrolled. In the
control group, the mean serum creatinine concentration increased
from 1.36 to 1.50 mg/dL, while in the ascorbic acid group it
only increased from 1.46 to 1.52 mg/dL. The increase in the
placebo group was significantly larger than in the ascorbic acid
CMN, by the
investigator’s definition, occurred in 9% of the ascorbic acid
group, compared to 20% of the control group.
mean baseline serum creatinine concentration and age tended to
be higher and the baseline creatinine clearance lower in the
ascorbic acid group. However, the ascorbic acid group still
showed a lower rate of CMN despite these random inbalances in
factors that have been shown in previous studies to increase the
risk of CMN.
The results of
this study show that ascorbic acid, a safe, well-tolerated,
inexpensive, and readily available oral antioxidant, appears to
prevent the occurrence of CMN after invasive coronary imaging
procedures in patients with pre-existing renal dysfunction.
Furthermore, these findings are consistent with the hypothesis
that CMN is caused in whole or in part by oxidative stress.
Elias Alexopoulos, MD; Stamatis Kyrzopoulos, MD; Panayiotis
Iacovis, MD; Darren C. Greenwood, MSc; Athanassios Manginas, MD;
Vassilis Voudris, MD; Gregory Pablides, MD; Christopher E.
Buller, MD; Dimitrios Kremastinos, MD; Dennis V. Cokkinos, MD