The TIMI (Thrombolysis in Myocardial Infarction) Risk Score for Unstable Angina/NSTEMI was developed by Antman and colleagues at Brigham and Women's Hospital in 2000, from the TIMI 11B and ESSENCE trial populations (1,957 patients). It was the first widely validated, bedside risk score for the entire spectrum of unstable coronary syndromes and remains the most-cited ACS risk score in the literature. The TIMI UA/NSTEMI score uses seven equally weighted binary variables, each contributing 1 point, to predict the composite endpoint of all-cause mortality, new or recurrent MI, or severe recurrent ischaemia requiring urgent revascularisation at 14 days. It fundamentally changed how emergency physicians and cardiologists approach ACS triage.