Coronary provocative tests in the catheterization laboratory: Pathophysiological bases, methodological considerations and clinical implications

The paradigm for the management of patients presenting with angina and/or myocardial ischemia has been historically centered on the detection and treatment of obstructive coronary artery disease (CAD). However, in a considerable proportion (30-50%) of patients undergoing coronary angiography, obstructive CAD is excluded. Thus, functional mechanisms may be involved in determining myocardial ischemia and should be investigated. In particular, coronary vasomotor disorders both at epicardial and at microvascular level may play a crucial role, but a definitive diagnosis of these disorders can at times be difficult, given the transience of symptoms, and often requires the use of coronary provocative tests. Of importance, these tests may provide relevant information on the pathogenic mechanism of myocardial ischemia, allowing physicians to tailor the therapies of their patients. Furthermore, several studies underscored the important prognostic information deriving from the use of coronary provocative tests. Nevertheless, their use in clinical practice is currently limited and mainly restricted to specialized centers, with only a minority of patients receiving a benefit from this diagnostic approach. In this review, we explain the pathophysiological bases for the use of provocative tests, along with their clinical, prognostic and therapeutic implications.