Inclusion Criteria:  For Pilot study, both health and patients with at least one epicardial coronary artery disease are included For both Training group and Validation group, patients must have at least one epicardial coronary artery disease Left ventricular ejection fraction > 30% Stable or unstable angina Myocardial infarction older than 1 month No active inflammation No scheduled non-cardiac surgery within 12 months eGFR > 30 ml/min/m2 Patients agree to participate in this study  Exclusion Criteria:  Severe liver dysfunction Blood platelet count <100 x 109/L Cancer On dialysis Pulmonary hypertension (defined as mean pulmonary arterial pressure > 25 mmHg and pulmonary vessel resistance > 3.0 Woods Unit)