N-acetyl cysteine reduces chromosomal DNA damage in circulating lymphocytes during cardiac catheterization procedures: A pilot study

Background: N-acetylcysteine (NAC) is considered a promising radio-protector for its antioxidant and anticarcinogenic properties. We examined the ability of NAC to confer protection against radiation-induced chromosomal DNA damage during cardiac catheterization procedures. Methods: Sixty-five patients (52 males, age 64.4 +/- 11.9 years) undergoing invasive cardiovascular procedures (peripheral transluminal angioplasty, n = 45; cardiac resynchronization therapy, n = 15 and ablation therapy n = 5) were enrolled: 35 patients (26 males, age 63.4 +/- 11.1 years) received the standard hydration protocol consisting of intravenous isotonic saline for 12 h after catheterization (Group I), and 30 patients (26 males, age 65.5 +/- 12.9 years) received a clinically driven double intravenous dose of NAC (6 mg/kg/h diluted in 250 mL of NaCl 0.9%) for 1 h before and a standard dose (6 mg/kg/h diluted in 500 mL of NaCl 0.9%) for 12 h following catheterization (Group II). Micronucleus assay (MN) was performed as biomarker of chromosomal DNA damage before, 2 and 24 h after the radiation exposure. Dose-area product (DAP; Gy cm(2)) was assessed as physical measure of radiation load. Results: DAP was higher in NAC-treated patients (I = 54.7 +/- 23.6 vs II = 126.2 +/- 79.2 Gy cm(2), p = 0.0001). MN frequency was 13.7 +/- 4.7 parts per thousand at baseline and showed a significant rise at 2 h (18.0 +/- 6.8 p = 0.01) and 24 h (17.6 +/- 5.9, p = 0.03) in the Group I. There was no significant increase of MN in the Group II (13.7 +/- 7.0, 15.5 +/- 6.0 and 14.9 +/- 6.3 for baseline, 2 h and 24 h respectively, p = 0.4).