Patients suitable for the study will be identified and screened for eligibility after being hospitalized for Acute Coronary Syndrome (ACS) (Visit 1) comprising ST Elevation Myocardial Infarction (STEMI) or Non-ST Elevation Myocardial Infarction (non-STEMI). At Visit 1, after signing informed consent, study measurements will take place at days 1, 3 and 5 post ACS, where feasible. It is planned that approximately 100 CAD patients will be randomized to ensure at least 66 evaluable patients receiving AZD5718 Dose B or placebo are included. For supporting dose selection in future studies, a treatment arm with 20 randomized patients receiving AZD5718 Dose A is included in the study.