Chest pain remains one of the most common, potentially serious presenting complaints for adults emergency department visits with approximately 7.6 million yearly visits in the united states. The priority for emergency physician is to determine whether these patients with acute chest pain have a potential life threatening underlying etiology. The great challenge is to differentiate patients presenting with acute coronary syndrome and those with other more benign conditions. Obviously, medical history, clinical examination, and laboratory values may help to identify patients with true ACS. None are sufficiently accurate to be used independently. Thus, about 5% of ACS patients are inappropriately discharged annually. Therefore, there is a global tendency for ED physician to overinvestigate chest pain patients with further, often more invasive testing, even in low-risk patients. This kind of practice leads to resource overutilization and a huge health costs waste contrasting with no outcomes improvement.

For many years, physicians were searching tools, ranging from specific diagnostic tests to entire strategies of evaluation, to appropriately risk stratify patients with chest pain in order to simultaneously prevent major adverse cardiac events and reduce unnecessary testing and hospitalisations. Based on the principal that a prompt quick and accurate identification of patients who are at high and low risk of developing major adverse cardiac events is paramount, and in order to optimally allocate ED and hospital resources, many bioclinical scores have been developed. One of the most known risk scores is TIMI score, which was originally derived and validated in a population of in-patients with unstable angina and non ST elevation myocardial infarction (NSTEMI). Its main performance is to predict early occurrence of major cardiovascular events (MACE). However, TIMI score like many other specific scores gave conflicting results when applied on chest pain patients in the ED. The HEART score is one of the more recently proposed model derived through a process involving expert opinion and review of medical literature. It is calculated based on admission data of medical history, EKG, age, cardiovascular risk factors and troponin levels. The HEART score was created specifically to identify ED patients presenting with undifferentiated chest pain who were at low risk as well as patients at high risk of short-term MACE occurrence. HEART score has been widely reported to outperform the TIMI and the GRACE scores. Several scientific societies are encouraging the use of HEART score, for evaluating patients with chest pain suggestive of ACS in the ED. A recent systematic review comprehensively compared the leading clinical prediction rules for chest pain, including the TIMI, the HEART, and the GRACE scores. Among the three risk stratification tools, the HEART score was found to be the most useful for managing patients with undifferentiated chest pain who present to the ED because it is simple, easy, and quick to use and it also has been validated in several studies conducted in the ED. Additional studies providing further worldwide data about the validation of this risk score will empower emergency physicians' decision making when relying on this score in ruling in or ruling out their chest pain patients. The goal of our investigation is to validate HEART score as a prognostication tool among ED patients with chest pain in teaching hospitals in Tunisia.