Supplementation With Polyphenol-Rich Foods and Atrial Fibrillation After a Cardiac Surgery

1. Study Rationale: An open heart surgery (OHS) induces injury of the vessel wall and is characterized by post-operative complications. Post-operative atrial fibrillation (POAF) is a major cause of morbidity and mortality after cardiac surgery. Both systemic inflammation and oxidative stress play a role in the initiation of POAF after a cardiac surgery. Consumption of polyphenol-rich foods (PRFs), such as fruits and vegetables, and beverages derived from plants, such as cocoa, red wine and tea, may represent a beneficial diet in terms of cardiovascular protection. Indeed, epidemiological studies demonstrate a significant inverse correlation between PRFs consumption and cardiovascular risk, due to antioxidant, vasorelaxant and antithrombotic properties of their polyphenolic components. In particular, procyanidins from grape seeds are the principal vasoactive polyphenols in red wine and protect endothelial cells from oxidative damage. However, there are no studies that have addressed the relationship of PRFs consumption with prognosis in patients undergoing an OHS.
2. Aim of the study. The main objectives of this project are to evaluate the association between the effect of polyphenol-rich food supplementation and post-operative atrial fibrillation (POAF) in patients undergoing an OHS.
3. Study design: Multicentre, randomized, placebo-controlled double-blind trial with 2 parallel arms: soluble corn flour at high content in anthocyanins and placebo. Placebo consists of soluble corn flour not rich in anthocyanins. The treatment will start at hospital admission until one day before cardiac surgery, and continue (4 days) after extubation and when the patients are reallocated to eat.
4. Study Population and recruitment: A total of 350 consecutive CAD patients undergoing to CABG or VR will be recruited. Participants will be identified at the Department of Cardiovascular disease of the clinical centers.

Eligible subjects will be recruited at their first surgical consultation and subsequently referred to the research investigators. The research staff in charge of the recruitment will pre-screen participants on the basis of inclusion/exclusion criteria and will explain the study at this time.

The main inclusion criteria are :age 18 years or older, presence of sinus rhythm on the screening electrocardiogram, first-time elective open heart surgery. Exclusion criteria are: absence of sinus rhythm at screening, known allergy or intolerance to gluten or anthocyanin compound, regularly consuming of anthocyanin or antioxidant supplements, being currently pregnant, existing or planned cardiac transplant or use of ventricular assist device, or being unable or unwilling to provide informed consent, known history of hepatic or renal disease, cancer and subjects with a history of substance abuse.

Once signed the informed consent, if the subject is eligible for the study according to the inclusion/exclusion criteria, he/she will be included into the trial and randomised, using prepared envelopes blinded to the study investigators, to receive daily high-anthocyanin supplement or placebo.

Subjects will start the dietary intervention at hospital admission until one day before cardiac surgery. Then they will continue the supplementation as soon they are reallocated to eat for the next 4 days after the surgery.