Functional testing as the most accurate tool for risk stratification in patients with micro-and macrovessel coronary artery disease

The scope of this review is to underline the diagnostic and prognostic significance of non-invasive tests, with special reference to myocardial perfusion scintigraphy and computed tomography angiography, to assess cardiac perfusion and anatomy in patients with micro- and macrovessel coronary disease. From available data it appears that functional testing should still be considered as the most accurate tool for the evaluation of patients with macrovessel coronary disease. In fact, the determination of the cardiac global ischemic burden remains the most important tool for the clinical management of patients with different types of ischemic heart diseases. For this purpose, several instrumental techniques can be adopted. Recent technological advancements have introduced the possibility to obtain physiologic evaluation of coronary stenosis by computed tomography angiography, thereby enabling this test to potentially provide an integrated anatomic-physiologic assessment of macrovessel coronary disease. Apart from the use of computational fluid dynamics to non-invasively calculate coronary fractional flow reserve, these advances also include evaluation of rest-stress myocardial perfusion from a typically acquired computed tomography angiography. Finally, the pathophysiologic potential role of endothelial dysfunction and its relation with myocardial perfusion in determining prognosis is also discussed. A potential increasing future role of coronary plaque characterization is hypothesized.