MYDA-MI study is a randomized, placebo controlled, double blind study performed in San Filippo Neri Hospital, Roma, Italy. The planned study duration is 18 months. The objectives are to assess the effects of pre-treatment with probiotic Ecoviesel on the incidence and magnitude of peri-procedural myocardial damage caused by coronary angioplasty in stable patients. 250 patients with chronic stable angina scheduled for a coronary angiography and possible ad hoc angioplasty will be randomized to receive pre-treatment with Ecoviesel sachets (each sachet contains 200 billions bacteria) or Placebo. The pre-treatment dosage will be 4 sachets of probiotic Ecoviesel or placebo for at least 2 weeks before the planned procedure. In patients undergoing angioplasty the same treatment will be continued for 4 weeks after PCI with secondary outcome measures performed at the end of this second stage.

Inclusion Criteria:

• Patients with chronic stable angina scheduled for coronary angiography and possible ad hoc percutaneous coronary intervention

Exclusion Criteria:

• Age >75 y.o
• Diabetes requiring treatment
• Abnormal c-TnI level before angiography
• Immunodeficiency status
• Need for oral vitamin K antagonists
• Need for antibiotics
• Use of antibiotics or probiotics within 4 weeks of enrollment
• Cancer and diseases affecting 1 year prognosis
• Participation in other clinical trials