Impact of angiotensin converting enzyme inhibition on post-coronary artery bypass interleukin 6 release.
BACKGROUND
Angiotensin 1 converting enzyme (ACE) inhibitors reduce morbidity and mortality after coronary artery bypass graft surgery (CABG). This benefit may result from an anti-inflammatory action.


OBJECTIVE
To examine the effect of ACE inhibition on interleukin 6 (IL-6) concentrations after CABG.


METHODS
161 patients undergoing elective first time CABG were recruited, of whom 41 (25%) were receiving ACE inhibitor treatment; 21 patients with confounding postoperative complications were excluded. After these exclusions there were 33 patients (24%) on ACE inhibitor treatment. Plasma IL-6 was measured preoperatively and again six hours after CABG.


RESULTS
Baseline IL-6 concentrations (geometric mean (SEM)) were non-significantly lower among the patients receiving ACE inhibitors (3.7 (0.1) v 4.3 (0.1) pg/ml, p = 0.12). Overall, post-CABG IL-6 concentrations increased significantly (mean rise 177 (12) pg/ml, p < 0.0005). This response was blunted among ACE inhibitor treated patients. Median increases in IL-6 concentrations were 117 v 193 pg/ml, for treated v non-treated patients, respectively (Kruskal-Wallis, p = 0.02), with peak postoperative IL-6 concentrations lower among the subjects receiving ACE inhibitors than in untreated subjects (142 (19) v 196 (13) pg/ml, p = 0.02). The effect of ACE inhibitors remained significant after multivariate analysis (p = 0.018).


CONCLUSIONS
ACE inhibitor treatment is associated with a reduction in IL-6 response to CABG. The data suggest that this class of drug may have a direct anti-inflammatory effect, which could explain some of its clinical benefit.
Brull
D J
DJ
UCL Centre for Cardiovascular Genetics, Rayne Institute, London, UK Department of Medicine, Glasgow Royal Infirmary, Glasgow, UK. d.brull@ucl.ac.uk
Sanders
J
J
Rumley
A
A
Lowe
G D
GD
Humphries
S E
SE
Montgomery
H E
HE
D000210:Acute-Phase Reaction / Q000378:metabolism; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D001026:Coronary Artery Bypass; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000378:metabolism / Q000517:prevention & control
D000806:Angiotensin-Converting Enzyme Inhibitors; D015850:Interleukin-6