This is a prospective, non-randomized, single center, open label clinical study enrolling patients affected by 1) chronic ischemic heart disease with evidence or suspect significant myocardial ischemia (group 1, CCS) or 2) acute coronary syndromes (group 2, ACS), both undergoing coronary angiography and eventually coronary revascularization at the Department of Scienze Cardiovascolari, Diagnostica per Immagini ed Emergenze Cardiovascolari of Federico II University Hospital, Naples, Italy. Age and sex-matched healthy volunteers without known ischemic heart disease (group 3, Ctr) will also be included as a control group. At enrollment (time 0), and after 48 hours (time 48 h), 1 month (time 1mo) and 6 month-follow-up visits (time 6 mo), clinical evaluation, ECG, trans-thoracic echocardiography and blood sampling will be performed, to isolate peripheral blood mononuclear cells (PBMC) and perform standard blood tests. The enrolment phase will last 24 months, and will likely involve 450 patients distributed as follows, according to the number of patients annually referring to our University Hospital: 1. Group 1, n= 200 patients with chronic ischemic heart disease undergoing coronary angiography and eventually coronary revascularization; 2. Group 2, n= 200 patients with ACS undergoing coronary angiography and eventually coronary revascularization ; 3. Group 3, n= 50, healthy volunteers.