CFR has been studied for few years using 82 Rubidium PET (positron emission tomography) /CT. CFR has shown to be correlated with cardiovascular events occurring in the 10 following years. CFR also helps to identify multivessel coronary disease. Few studies have shown the possibility to calculate CFR during myocardial perfusion SPECT on new ultrafast CZT cameras.

Evaluate the contribution of CZT SPECT CFR in cardiovascular risk stratification: correlation with clinical scores, with calcium score, and when pathological with coronarography findings especially fractional flow reserve (FFR).

Inclusion Criteria:

• Patients referred for myocardial ischemia screening

Exclusion Criteria:

• Patient already suffering from coronary disease with angioplasty, bypass surgery or myocardial infarction.
• Contraindications related to the stress test:

Acute Coronary Syndrome <5 days Unstable angina Stenosis of left main artery untreated Uncontrolled severe rhythm disorders Uncontrolled heart failure

• Contraindications to dipyridamole and regadenoson:

Hypotension (systolic <90mmHg) Severe pulmonary arterial hypertension Bradycardia <40 beats / minute Sinusal Dysfunction and 2nd or 3rd degree Atrioventricular block Decompensated Heart Failure with Ejection Fraction <25% Stenosis of supra-aortic trunks unilateral> 70% or bilateral> 50% Dipyridamole and regadenoson allergy

• Patients with pacemaker, or who have had valvular surgery,
• Well-known dilated cardiopathy
• Pregnant or breastfeeding women,
• Minor people
• Persons under guardianship or under guardianship