Asymmetric dimethylarginine and oxidative stress following coronary artery bypass grafting: associations with postoperative outcome

OBJECTIVES: Elevated asymmetric dimethylarginine (ADMA) is associated with an increased risk of coronary artery disease. A prognostic value of ADMA following coronary artery bypass grafting (CABG) is unknown. The aim of the current study was to assess the effect of CABG on ADMA and oxidative stress and determine their associations with postoperative complications. METHODS: In 158 consecutive patients (35 women, 123 men, aged 65.2 ± standard deviation 8.2 years) undergoing isolated, elective CABG procedure, we measured plasma ADMA and 8-iso-prostaglandin F2α (8-iso-PGF2α) preoperatively and twice postoperatively: 18-36 h and 5-7 days after surgery. The primary end points were postoperative myocardial infarction (PMI) and in-hospital cardiovascular death. RESULTS: ADMA increased from 0.56 ± 0.06 μmol/l at baseline by 68% to 0.94 ± 0.11 μmol/l at 18-36 h after CABG, and then decreased by 20% to 0.75 ± 0.12 μmol/l on 5-7 days postoperatively (P = 0.0001 for all comparisons). A similar pattern of changes was observed for 8-iso-PGF2α. Thirteen (8.2%) patients developed PMI, and 6 patients (3.8%) died during the early postoperative period because of extensive PMI. PMI and early perioperative mortality were positively associated with ADMA and 8-iso-PGF2α. CONCLUSIONS: A marked increase of ADMA and oxidative stress is observed within the first days following CABG, and is associated with unfavourable early post-CABG outcomes, including PMI and in-hospital cardiovascular death.