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.

Inclusion Criteria:

• Patient scheduled for coronary function test, comprising of intracoronary bolus thermodilution measurements of microvascular function, and/or intracoronary vasoreactivity tests with acetylcholine.
• Subject understands the study requirements and provides written informed consent.

Exclusion Criteria:

• Subject is participating in another investigational clinical trial that may cause non-compliance with the protocol or confound data interpretation.
• Subject intends to participate in another investigational clinical trial that may cause non-compliance with the protocol or confound data interpretation.
• Documented or suspected pregnancy.
• Inability to provide written informed consent.

Current registry includes each patient in which coronary function tests are performed. The indication for coronary function tests is left to the descretion of the operator. The study population will be broader than the classic use of coronary function tests for angina and non-obstructive coronary arteries (ANOCA).