The aim of the present study is to investigate whether the ingestion of a cocoa flavanol-containing drink compared to a flavanol-free drink, improves coronary vasomotion and platelet function in patients with overt coronary artery disease acutely (after 2 hours)

Inclusion Criteria:

Patients with coronary artery disease undergoing elective coronary angiography with or without the need of coronary intervention

• Age 20 - 80
• Written obtained informed consent

Exclusion Criteria:

• Acute ST-elevation myocardial infarction
• Acute non-ST-elevation myocardial infarction (enzyme positive)
• Ventricular tachy-arrythmias or AV-Block >I°
• Renal insufficiency (GFR MDRD < 30ml/min) or liver disease (ALT or AST >150 IU)
• Pregnancy
• Known allergy to compounds of cocoa product
• Known allergy to contrast media
• Known allergy to nuts
• Intolerance to coffein and theobromin
• Acute infectious disease
• Disease with systemic inflammation (e.g. rheumatoid arthritis, M. Crohn)
• Participation in another study within the last month
• Concomitant vitamin supplements and herbal remedies, as well as fruit and tea extracts
• No study visits ± 1 week before Eastern, Christmas and New Year holyday (altered eating habits)
• Extreme eating habits (as assessed by a questionnaire)
• Alcohol or drug abuse
• Lactose intolerance