TAIPEI, TAIWAN. Cardiac angiography and angioplasty can be hard on the kidneys because of the deleterious effects of the contrast medium (iopamidol) injected in order to facilitate the viewing of the heart during the procedure. This problem is especially serious for patients already suffering from renal (kidney) failure. Taiwanese researchers now report that oral supplementation with the antioxidant acetylcysteine largely eliminates the worsening of existing kidney problems. Their clinical trial included 121 patients with chronic renal insufficiency (mean serum creatinine level of 2.8 mg/dl). The patients were randomized to receive either 400 mg of acetylcysteine twice a day on the day prior to the procedure and on the day of the procedure or placebo. Both groups also received saline infusions (0.45%) at a rate of 1 mL/kg body weight per hour for 12 hours before and 12 hours after angiography. An acute contrast medium-induced reduction in renal function occurred in 25% of the patients in the control group, but in only 3% of the patients in the acetylcysteine group. The average creatinine level among the control patients increased from 2.8 mg/dL to 3.1 mg/dL 48 hours after injection of the contrast agent. The acetylcysteine group, on the other hand, saw a drop in average creatinine level from 2.8 mg/dL to 2.5 mg/dL.
The researchers conclude that acetylcysteine protects against contrast medium-induced kidney damage, not
only in patients with moderate renal insufficiency, but also in those with severe renal insufficiency.
Editor's comment: Contrast medium injection is toxic to kidney cells and causes a marked increase in free radical production in the kidneys. Thus it would seem to me that acetylcysteine supplementation prior to and during angiography and angioplasty may also be a good idea for patients with healthy kidneys.