Prostaglandin E1 Increases the Blood Flow Rate of Saphenous Vein Grafts in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

ObjectiveTo compare the effects of prostaglandin E1 (PGEl) versus placebo on blood flow rate in coronary artery bypass grafts.DesignA prospective, randomized, double-blinded study.SettingA teaching hospital.ParticipantsForty-six patients with stable angina scheduled for isolated elective OPCAB were recruited and randomized into group PGE1 and group placebo.InterventionFollowing randomization, the patients in the PGE1 group (Group PGE1, n = 23) received a continuous intravenous infusion of PGEl (10 ng/kg/min) after endotracheal intubation and the placebo group (Group placebo, n = 23) received the same volume of normal saline. The infusion administration was removed after leaving the intensive care unit.Measurements and Main ResultsThe grafts' blood flow rate was measured with a transit time flowmeter at 10 minutes and 30 minutes after coronary artery grafting. The hemodynamic parameters, including mean arterial pressure (MAP), heart rate, and SvO2, VO2I, DO2I, ERO2 monitored by a pulmonary artery catheter, were recorded. The blood flow of the saphenous vein grafts was significantly higher in the PGE1 group than the placebo group at both 10 and 30 minutes after coronary artery grafting. At the 10-minute mark, the graft flow was 54.9±31.4 mL/min versus 47.3 ±24.6 mL/min in venous nonsequential grafts to the left coronary artery for group PGE1 and placebo (p = 0.000). Corresponding values at 30 minutes were 60.1±27.8 mL/min versus 48.4±26.3 mL/min (p = 0.002). In the venous non-sequential grafts to the right coronary artery, a tendency of blood flow also was found to be higher in the PGE1 group than in the placebo group at 10-minutes (52.7±29.4 mL/min versus 49.3 ±23.8 mL/min, p = 0.048) and the 30-minutes (58.6±26.5 mL/min, 50.9±25.9 mL/min, p = 0.037). The blood flow rate of the left internal mammary artery (LIMA) grafts in group PGE1 was higher than that in the placebo group but did not reach statistical significance. The VO2I, DO2I, and ERO2 in the 2 groups at the 2 time points did not reach statistical significance. The cardiac index (CI) in group PGE1 was higher than that of the placebo group at T3 and T4 (p = 0.035 and p = 0.012, respectively). The lactate (LAC) at the end of the operation (T2), 4 hours after the operation (T3), and 24 hours after operation (T4) in the placebo group were higher than that of group PGE1 (p = 0.023, p = 0.015, and p = 0.043, respectively). The oxygenation saturation of the mixed venous blood (SvO2) in the 2 groups was decreased but without significant difference.ConclusionPGE1 significantly increased the flow rate in anastomosed saphenous vein grafts, and its beneficial effects on hemodynamics and oxygen metabolism were observed.