Patients with chest pain suggestive of angina after ruling out other cardiac and non-cardiac causes, referred for invasive coronary angiography, will be evaluated by coronary angiography and invasive coronary physiological assessment by determining FFR and IMR and by performing a vasoreactivity test with acetylcholine.~A relationship will be established between the invasive physiological assessment with FFR and IMR and biological markers such as micro-RNA's according to the affected coronary vascular compartment (Group 1: Macrovasculature + / Microvasculature +; Group 2: Macrovasculature + / Microvasculature -; Group 3 : Macrovasculature - / Microvasculature +; Group 4: Macrovasculature - / Microvasculature -). In addition, the biological markers will be related to the presence of microvascular spasm or macrovascular spasm (Group 5).~Finally, among other biological markers, the following miRNAs will be compared. These miRNA's present consistent data in the literature about their over or underexpression.
Relationship between invasive physiological assessment with FFR and IMR and biological markers as micro-RNA's according to coronary vascular compartiment affected (Group 1: Macrovasculature + / Microvasculature +; Group 2: Macrovasculature + / Microvasculature -; Group 3: Macrovasculature - / Microvasculature +; Group 4: Macrovasculature - / Microvasculature -). Also, biological markers will be related with presence of microvascular spasm or macrovascular spasm (Group 5).