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 12h 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 1h before and a standard dose (6 mg/kg/h diluted in 500 mL of NaCl 0.9%) for 12h following catheterization (Group II). Micronucleus assay (MN) was performed as biomarker of chromosomal DNA damage before, 2 and 24h 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 ‰ at baseline and showed a significant rise at 2h (18.0 ± 6.8 p=0.01) and 24h (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, 2h and 24h respectively, p=0.4).

CONCLUSION: NAC treatment given to prevent contrast-induced nephropathy may also reduce DNA damage induced by ionizing radiation exposure during cardiac catheterization procedures.