Coronary atherosclerosis is the most common cause of ischaemic heart disease. About 40-50% of patients with symptoms and documented ischaemia on non-invasive tests do not show obstructive coronary artery disease on coronary angiography. This cause of ischaemic heart disease called INOCA (Ischemic Non-Obstructive Coronary Artery), far from having a benign prognosis, is associated with an increase in major adverse cardiac events (MACE) as well as increased functional limitation. The current European Society of Cardiology clinical practice guidelines for the management of chronic coronary syndrome establish for the first time a IIa recommendation for the invasive analysis of coronary flow reserve (CFR) and microvascular resistance index (MRI) in symptomatic patients with INOCA. The acetylcholine (Ach) test, based on intracoronary (ic) administration, is established as indication IIb for the assessment of micro or macrovascular vasospasm in patients with suspected vasospastic angina (VSA) (4). A national multicentre registry would allow us to determine the prevalence of INOCA and its different endotypes in our setting.