The goal of this prospective, multicenter registy is to describe the 'real-world' use of coronary function tests, which may consist of bolus thermodilution measurements of coronary microvascular function and/or invasive vasoreactivity tests with acetylcholine, in the current Belgian routine practice. The main questions it aims to answer are: * how frequent are coronary function tests performed * what is the indication for coronary function tests * what is the frequency of coronary microvascular dysfunction * what is the frequency of coronary artery vasospasm From each participant, data will be collected from their medical files concerning cardiovascular risk factors, relevant past medical history, non-invasive tests, procedural data, and follow-up data from routine in-patient visits. Their are no specific study visits. Optionally, patients will be asked to fill in questionnaires about anginal symptoms and quality of life.