Invasive coronary angiography is currently considered gold standard in the assessment of coronary artery disease although the method has limitations. Most importantly invasive angiography only depicts coronary anatomy without determining its physiological significance i.e the likelihood that the stenosis impedes oxygen delivery to the heart muscle. Fractional flow reserve (FFR) is a catheterization technique for assessing the physiological significance of a coronary artery lesion during invasive coronary angiography. Coronary computed tomographic angiography (CCTA) is a noninvasive imaging test that has become an alternative route to diagnosis for patients with suspected coronary artery disease. Computational fluid dynamics combined with anatomical models based on CCTA scans allows determination of coronary flow and pressure, and has emerged as a promising diagnostic modality called CT-FFR. In this Project New Mathematical algorithms are developed for computation of CT-FFR. The main objective of this study is to determine the diagnostic accuracy of CT-FFR values obtained by the new method compared with invasive coronary angiography with fractional flow reserve and state-of-the-art dobutamin stress echocardiography.

Inclusion criteria

• Proven stenosis by CCTA that require further investigation with invasive coronary angiography i.e. patients with estimated stenosis ≥30- 50%.
• Informed consent

Exclusion Criteria:

• Patients with unstable coronary artery disease.
• Previously treated with PCI or coronary surgery.
• Severe renal impairment i.e. GFR <30ml / min
• Contrast allergy
• Contraindication to adenosine / nitroglycerin / beta-blocker
• BMI> 40
• Patients referred on the basis of technically unsuccessful CTA, motion artifact or similar