When Cardiac Computed Tomography Becomes the Gold Standard Technique to Evaluate Coronary Artery Disease Patients (original) (raw)

2011, Coronary Angiography - Advances in Noninvasive Imaging Approach for Evaluation of Coronary Artery Disease

Worldwide the health expenditures as a percentage of each national gross domestic product continue to rise. Cardiovascular diseases as part of the noncommunicable disease group, according to the World Health Organization and the most important scientific associations, are growing due to the aging of the population and the increase of cardiovascular risk factors, due to the epidemiologic as well as to the health transition, especially in the developing countries, which account for the majority of the population in the world (Lopez et al., 2006). In the last few decades we witnessed a proliferation of diagnostic tests to evaluate cardiac heart diseases and in particular coronary artery disease (CAD): exercise stress test, transthoracic echocardiography, stress echocardiography, stress single photon emission computed tomography, myocardial perfusion imaging, magnetic resonance, fractional flow reserve, electron beam computed tomography. Each diagnostic test, which continuously evolves due to technological improvements, proved to have a high sensibility, specificity and good accuracy in identifying symptomatic as well asymptomatic CAD patients. All these tests are however unable to give us information about the anatomy of the coronary arteries, which is essential to provide a treatment that goes beyond the medical treatment and in particular when cardiac surgery is needed. In fact catheter angiography or invasive coronary angiography (ICA), since its introduction in the second half of last century, was the only test able to visualize, in vivo, the coronary tree and to provide images of the coronary artery anatomy upon which both cardiologists and surgeons decide if a patient should be revascularized or medically treated. With time ICA increased its performance due to the improvement in its software and hardware (quantitative coronary angiography, flat panel digital detectors), and due to the introduction of important tools which can be used routinely like intravascular coronary ultrasound, that for the first time visualized, in vivo, the presence of non calcified plaques and vessel's positive remodeling. There are other interesting tools that can be associated to ICA, but, for the moment, are the armamentarium of some specialized centers and mainly used for research purposes like elastography, spectroscopy, angioscopy, thermography and optical coherence thermography. www.intechopen.com Coronary Angiography-Advances in Noninvasive Imaging Approach for Evaluation of Coronary Artery Disease 200 All this data places ICA as the "reference" technique or "gold standard" technique to study the anatomy of coronary arteries. ICA has been widely employed to validate the results obtained with functional procedures, even though the anatomical findings of ICA are also judged by functional tests (Winchester et al., 2010). These interdependence of validation shows how a technique, even ICA, cannot be considered the unique "gold standard" technique to study CAD patients. In fact clinicians while studying their patients have to consider more than one question (diagnostic question, prognostic question, therapeutic question) and ICA alone is unable to give an exhaustive answer to all these questions (Mark et al., 2010). This is the reason why we are in search for technologies to evaluate CAD patients and in particular to study the anatomy of their coronary arteries keeping in mind that these new tests have to be feasible, able to compete with ICA in providing accurate information and, last but not least, economically affordable.