Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease 3

In a cohort of symptomatic patients referred to coronary computed tomography angiography (CCTA), the investigators aim is: 1. To investigate and compare the diagnostic precision of Rubidium Positron Emission Tomography (Rb PET) and 15O-water PET (15O-water PET) in patients where CCTA does not exclude obstructive coronary artery disease (CAD) using invasive coronary angiography with fractional flow reserve (ICA-FFR) as reference standard. 2. To study the diagnostic accuracy and prognostic value of computed tomography fractional flow reserve (CT-FFR) in patients where CCTA does not exclude obstructive CAD with ICA-FFR as reference standard. 3. To validated a pre-test probability model including genetic and circulating biomarkers. 4. To identify and characterize genetic risk variants and circulating biomarkers importance in developing CAD. 5. To evaluate the bone mineral density in the hip and spine and correlate this to the degree of vascular calcification.