This study aims to investigate the extent to which the time to angiography impacts on survival in patients hospitalised with NSTEMI. It will characterise patients according to their estimated risk of death, their time to angiography, and associated outcomes. The investigators anticipate that this observational study will provide Level B evidence for the benefits of the timing of an invasive strategy according to the GRACE risk score. The investigators are aware that the NICE guidelines for the management of acute chest pain are to be updated in 2016.