Relation of inflammatory cytokines to atrial fibrillation after off-pump coronary artery bypass grafting.
OBJECTIVE
It has been observed that a systemic inflammatory response after on-pump coronary artery bypass grafting (CABG) participates in the pathogenesis of postoperative atrial fibrillation (AF). In patients undergoing off-pump CABG, it is plausible that inflammation is associated with the development of postoperative AF. The present study examined relation of proinflammatory cytokines, which play an important role in the upstream of inflammatory cascade, to the development of AF after off-pump CABG.


METHODS
The present study included 39 patients undergoing off-pump CABG. Tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, and IL-8, were measured by enzyme-linked immunosorbent assay, on anesthetic induction, after sternotomy before anastomoses, at the completion of anastomoses, 3 and 6h thereafter, and on postoperative days (POD) 1-4. C-reactive protein (CRP) was also measured by turbidimetric immunoassay, preoperatively, and on POD 1, 2, 3, 6, 9, and 13.


RESULTS
Eleven patients (28%) developed postoperative AF. Patients with postoperative AF were older (70+/-6.4 years vs 60+/-8.8 years, P=0.001); however, there was no difference in other pre- and perioperative variables. TNF-alpha level did not change during the study period. However, IL-8 and CRP levels significantly increased after the surgery, although there was no significant difference between the two groups. IL-6 level also increased after the surgery with its peak at 6h after the completion of anastomoses. IL-6 levels of 3 and 6h after anastomoses were significantly higher in patients with postoperative AF (360+/-143 pg/ml vs 230+/-94 pg/ml, P=0.0047, 435+/-175 pg/ml vs 247+/-102 pg/ml, P=0.0005, respectively). Logistic regression analysis indicated that the highest quartile of IL-6 level immediately after the surgery (odds ratio 7.63; 95% CI, 1.06-54.9; P=0.04) and age (odds ratio 1.18; 95% CI, 1.01-1.39; P=0.04) independently predict postoperative AF. Furthermore, the maximum level of IL-6 immediately after the surgery significantly correlated to age and intraoperative blood loss (r=0.04, P=0.01, and r=0.47, P=0.04, respectively).


CONCLUSIONS
Advanced age was a major risk factor for postoperative AF. Furthermore, inflammatory response induced by surgical trauma was also associated with the development of AF after off-pump CABG.
Ishida
Keiichi
K
Department of General Surgery, Graduate School of Medicine, Chiba University, Inohana 1-8-1 Chuo-ku, Chiba 260-0856, Japan.
Kimura
Fumio
F
Imamaki
Mizuho
M
Ishida
Atsushi
A
Shimura
Hitoshi
H
Kohno
Hiroki
H
Sakurai
Manabu
M
Miyazaki
Masaru
M
D000367:Age Factors; D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood* / Q000209:etiology; D015415:Biomarkers / Q000097:blood; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects*; D003327:Coronary Disease / Q000473:pathology / Q000601:surgery; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D018746:Systemic Inflammatory Response Syndrome / Q000097:blood / Q000209:etiology*
D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators; D015850:Interleukin-6