title: Fish oil before cardiac surgery: neutrophil activation is unaffected but myocardial damage is moderated.
abstract: Could pre-operative dietary intervention with fish oil reduce neutrophil activation and myocardial damage associated with cardiopulmonary bypass (CPB)? Patients were randomised to receive either 8 g/day fish oil (n=22) or placebo (n=18) for 6 weeks. Neutrophil activation, apoptosis and cardiac damage were measured. Demographics and operative variables were similar. Fish oil diet decreased plasma VLDL from 0.69+/-0.34 to 0.51+/-0.24 mmol/l and triglycerides from 1.68+/-0.70 to 1.39+/-0.54 mmol/l. HDL cholesterol increased from 0.94+/-0.27 to 1.03+/-0.26 mmol/l demonstrating significant treatment effects (P=0.007, 0.02 and 0.0003, respectively) as well as compliance with treatment. There were no significant differences in ex vivo N-formyl-methionyl-leucyl-phenylalanine-stimulated neutrophil superoxide anion generation or myeloperoxidase release at recruitment, pre-operatively and at end-CPB. Apoptosis at end-CPB was equally reduced in both groups from 23+/-9% to 13+/-4% in the fish oil group (P<0.001) and 35+/-14% to 15+/-3% in the placebo group (P=0.001). At end-CPB overall troponin I levels averaged 0.91+/-0.60 ng/ml which clearly exceeded diagnostic levels (0.15 ng/ml). At 24h troponin I fell significantly in the fish oil group to 46+/-23% of end-CPB levels (P=0.0002) whereas it peaked in the placebo group to 107+/-72% (P=0.098 vs. end-CPB); this difference was significant: P=0.013. At 48 h the placebo-treated patients had higher troponins but not significantly so (P=0.059). Area-under-the-curve analysis did not conclusively support this (P=0.068). We conclude that fish oil did not significantly decrease post-CPB neutrophil activation (as detected ex vivo) but may moderate post-operative myocardial damage.
authors.affiliation: Centre for Nutrition & Food Research, Queen Margaret University College, Edinburgh EH12 8TS, UK.
authors.forename: A
authors.initials: A
authors.lastname: Charman
authors.forename: E W
authors.initials: EW
authors.lastname: Muriithi
authors.forename: E
authors.initials: E
authors.lastname: Milne
authors.forename: D J
authors.initials: DJ
authors.lastname: Wheatley
authors.forename: R A
authors.initials: RA
authors.lastname: Armstrong
authors.forename: P R
authors.initials: PR
authors.lastname: Belcher
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D016063:Blood Loss, Surgical; D002315:Cardiopulmonary Bypass; D004311:Double-Blind Method; D005260:Female; D005395:Fish Oils / Q000494:pharmacology* / Q000627:therapeutic use; D006321:Heart / Q000187:drug effects*; D006801:Humans; D007958:Leukocyte Count; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology*; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation / Q000187:drug effects*; D009504:Neutrophils / Q000378:metabolism / Q000473:pathology; D009195:Peroxidase / Q000378:metabolism; D019106:Postoperative Hemorrhage; D013481:Superoxides / Q000378:metabolism; D019210:Troponin I / Q000378:metabolism
chemical_list: D005395:Fish Oils; D008055:Lipids; D019210:Troponin I; D013481:Superoxides; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009195:Peroxidase