15. Coagulation : Should include Prothrombin Time (PT) or International Normalized Ratio (INR) and Partial Thromboplasti n Time (PTT). Samples will be analyzed locally. 16. Cardiac Troponin : For participants undergoing screening, circulating levels of cardiac Troponin - I (cTnI) must be measured and found to be within the normal reference range within 28 days before study entry , preferably using the central laboratory kits provided. See Section 7.1.8 for full details.