[Thoracic pain and myocardial ischemia. Applications of the Bayes theorem for the rational use of stress-test including echocardiography-dobutamine].

Chest pain, one of the cardinal manifestations of cardiovascular disease, is a symptom of many other diseases. The diagnosis of coronary artery disease is often difficult to relieve on history and physical examination, so many sophisticated tests have been developed to allow an early and more accurate diagnosis. Physicians must decide the appropriate indications and strategies to correctly utilize different non-invasive diagnostic tests, in order to minimize the risks and maintain the cost effectiveness of their decisions. The Bayes' theorem can be utilized to calculate the probability of coronary artery disease starting from clinical data and multiple non-invasive tests results. This is a mathematical method by which the results of the different tests can be integrated into a quantitative statement of the post-test probability of coronary artery disease to reach a more accurate final prediction of the chance of disease. The prevalence of the pre-test probability of disease can be determined in every patient from informations readily obtained by clinical evaluation, in accordance with the data of the Framingham and other studies. The post-test likelihood of disease depends on the sensitivity and specificity of the test: this estimate, before any test is performed, is crucial both for further decisions on the need for other tests and for determining the final likelihood of coronary artery disease.