We sought to investigate the effect of multiple coronary artery bypass grafting (CABG)
with or without cardiopulmonary bypass (CPB) on the perioperative inflammatory response.
Sixty patients undergoing CABG were randomly assigned to one of two groups: (A) on
pump with conventional CPB and cardioplegic arrest, and (B) off pump on the beating
heart. Serum samples were collected for estimation of neutrophil elastase, interleukin
8 (IL-8), C3a, and C5a preoperatively and at 1, 4, 12, and 24 hours postoperatively.
Furthermore, white blood cell (WBC), neutrophil, and monocyte counts were carried
out preoperatively and at 1, 12, 36 and 60 hours postoperatively. Overall incidence
of infection and perioperative clinical outcome were also recorded.
The groups were similar in terms of age, weight, gender ratio, extent of coronary
disease, left ventricular function, and number of grafts per patient. Neutrophil elastase
concentration peaked early after CPB in the on-pump group, with a decline with time.
Repeated-measures analysis of variance between groups and comparisons at each time
point (modified Bonferroni) showed elastase concentrations were significantly higher
in the on-pump than the off-pump group (both p < 0.0001). IL-8 increased significantly
after surgery in the on-pump group, with no decline during the observation period
(p = 0.01 vs off pump). C3a and C5a rose early after surgery in both groups when compared
with baseline values. Postoperative WBC, neutrophil, and monocyte counts were significantly
higher in the on-pump than the off-pump group (p < 0.01). Finally, the incidence of
postoperative overall infections was significantly higher in the on-pump group (p
< 0.0001 vs off pump).
CABG on the beating heart is associated with a significant reduction in inflammatory
response and postoperative infection when compared with conventional revascularization
with CPB and cardioplegic arrest.