The aim of the study is to assess presence of myocardial ischemia by contrast stress echocardiography in patients with symptomatic non-obstructive coronary artery disease (CAD) by CT-coronary angiography, and the clinical, vascular, biochemical and genetic markers of myocardial ischemia in such patients.

Non-obstructive coronary artery disease (CAD) is particularly common in women and associated with reduced quality of life and increased cardiovascular morbidity and mortality. The project will recruit patients with angina pectoris and non-obstructive CAD by CT- coronary angiography for further imaging with contrast stress echocardiography for diagnosis of myocardial ischemia. Better characterization of patients with symptomatic non-obstructive CAD due to myocardial ischemia will be done by vascular assessment by tonometry, biochemical and genetic markers as well as quality of life questionnaire. This interdisciplinary project is expected to add new knowledge to the impact of multimodality cardiac imaging in improving diagnosis in patients with symptomatic non-obstructive CAD.

Inclusion Criteria:

• Age >30 years
• Chest pain and or functional dyspnoea with a duration > 6 months
• Non-obstructive coronary artery disease detected by CT coronary angiography

Exclusion Criteria:

• Significant coronary artery stenosis or normal coronary arteries by CT coronary angiography
• Unstable coronary artery disease
• Significant valvular heart disease
• Mechanical valve prosthesis
• Significant arrhythmia
• Severly reduced pulmonary function (GOLD 3-4)
• Known allergy to ultrasound contrast agents
• Pregnancy
• Inability to sign informed consent to participate
• Other severe disease

The study population include 132 patients with symptomatic angina pectoris and non-obstructive coronary artery disease detected by CT-coronary angiography