Quercetin in Coronary Artery By-pass Surgery

After being informed about the study and the potential risk, all patients giving written informed consent will be randomized in a double-blind manner (participant and investigators) on 1:1 ratio to receive quercetin (500 mg twice daily) or placebo (twice daily) starting 2 days before a coronary artery by-pass graft surgery and for the duration of their hospitalization but up to 10 days (i.e. up to 7 days post-surgery). Blood (5 ml) will be collected the first morning after recruitment (t-1), 24h post-surgery (t1), day 4 post-surgery (t2) and day of hospital discharge for blood analyses. During the surgery, if a discarded segment of mammary artery is available, it will be collected for laboratory work. Health status will be assessed during the follow-up visit 8 to 12 weeks post-surgery.

Inclusion criteria

• to be able to speak French or English;
• to be able to give free and enlighten consent;
• be hospitalized and waiting for a cardiac surgery of revascularization;
• to have had a myocardial infarction (MI) within the past 30 days or to be in a state of stable angina before the surgery.

Exclusion criteria

• to be in a stable state without MI in the last 30 days;
• have a cardiac surgery concomitant to the cardiac surgery of revascularization;
• have an infection in the last 30 days;
• to have renal insufficiency (GFR less than 30);
• to have a liver disease (AST, ALT or bilirubin ˃ 2X normal values);
• to have a known cirrhosis;
• to have a past history of breast cancer or other tumors estrogen-dependent;
• to be intolerant to flavonoids, niacine or ascorbic acid;
• take quinolone;
• need for a quinolone during post-op;
• not being able to give a free and enlighten consent;
• not being able to speak French of English;
• take quercetin as a supplement.