The Troponins in ACS page has been updated with some additional information about single value hsTnI to rule out ACS. The bottom line is that hsTnT is probably more sensitive than hsTnI for clinically significantly outcomes, so is currently preferred.
Carlton, E, Greenslade, J, Cullen, L, et al. Evaluation of High-Sensitivity Cardiac Troponin I Levels in Patients With Suspected Acute Coronary Syndrome. JAMA Cardiology 2016