L-arginine cardioplegia reduces oxidative stress and preserves diastolic function in patients with low ejection fraction undergoing coronary artery surgery

L-arginine cardioplegia decreases biochemical markers of myocardial damage and oxidative stress in patients with normal left ventricular function. We investigated the effects of L-arginine supplemented cardioplegic arrest in patients with reduced ejection fraction. Fifty-three adult patients with left ventricular ejection fraction −1 (15 minutes) (P=0.0004). Superoxide dismutase activity was higher in L-arginine group, 229±87 vs 191.3±68 (5 minutes), 229±54 vs 198±15 nmol.minute−1.ml (15 minutes) (P=0.005). Lactic acid flux was lower in the L-arginine group, 0.15±0.23 vs 0.48±0.32 (1 minute), 0.08±0.19 vs 0.38±0.31 (5 minutes) and −0.15±0.13 vs 0.26±0.30 mmol.l−1 (15 minutes), (P=0.0003). There was no difference in left ventricular systolic function. The mitral annular tissue Doppler inflow (eʹ) velocity during early diastole improved in the L-arginine group following cardiopulmonary bypass (control 4.2±1.9 cm.s−1 to 3.6±1.2 cm.s−1 vs L-arginine 3.8±1.2 cm.s−1 to 4.6±1.4 cm.s−1) (P=0.018). In patients with reduced ejection fraction, L-arginine supplemented cardioplegic arrest did not affect postoperative cardiac troponin-I levels, but attenuated cardiac cellular peroxidation and improved early left ventricular diastolic function.