This is an old study by Annals of EM, The Role of Cardiac Risk Factor Burden in Diagnosing Acute Coronary Syndromes in the Emergency Department Setting, Feb 2007. Of 10,806 eligible patients, 871 (8.1%) had acute coronary syndromes. Cardiac risk factors was identified: diabetes, hypertension, smoking, hypercholesterolemia, and family history of coronary artery disease. Interestingly in patients less than 40 years old without cardiac risk factors had a negative likelihood ratio of 0.17 and having 4 or more risk factors had a positive likelihood ratio of 7.39. In patients between 40 and 65 years of age, having no risk factors had a negative likelihood ratio of 0.53, and having 4 or more risk factors had a positive likelihood ratio of 2.13. In patients older than 65 years, having no risk factors had a negative likelihood ratio of 0.96 , and having 4 or more risk factors had a positive likelihood ratio of 1.09. The conclusion was:”Cardiac risk factor burden has limited clinical value in diagnosing acute coronary syndromes in the ED setting, especially in patients older than 40 years”.