Evaluation of Diagnostic Accuracy, Safety, and Cost-Effectiveness of the Non-Invasive Cardiolens FFR-CT Pro Method to Measure the Fractional Flow Reserve in Diagnostics of Chronic Coronary Syndromes Versus the Standard Diagnostic Modalities.

Stage 1

After a patient declares their consent, a doctor or another member of the study team trained by the sponsor will perform procedures in the following order:

• Define the unique patient ID to be recorded in the CRF with the patient's demographic data
• Assess the quality of CCTA imaging data (DICOM) according to guidelines agreed upon with the sponsor and record the number and location of the significant (≥50%) stenosis sites in the CRF based on CCTA
• No later than one hour before ICA starts, perform a physical examination consisting in instantaneous peripheral blood pressure (systolic and diastolic) resting measurement performed with a standard sphygmomanometer and Continuous Non-Invasive Blood Pressure measurement (1-3 min).

Stage 2

After the procedures mentioned above are performed, the patient will undergo elective ICA with the outcomes, i.e.:

• video material showing the location of the wire during the FFR measurement,
• digital pressure signals exported from the FFR measuring device used to determine the value of the invasive FFR,
• values of FFR measurements obtained during ICA will be entered after being anonymised in a dedicated HEMOFLOW PMS_2020 reference database.

Stage 3

Within 48 hours of ICA completion a doctor or another member of the study team trained by the sponsor:

• will enter the following data in the Cardiolens FFR-CT Pro system:

• Patient's data, i.e. patient's ID, gender, height, body mass, exercise tolerability, information on used medications and smoking cigarettes. Optionally, i.e. if upon admission for ICA a blood test was performed as a part of the standard diagnostic workup - haematocrit levels and total protein concentration
• Files containing CCTA imaging data in the DICOM format.
• Values of instantaneous peripheral blood pressure (systolic and diastolic) resting measurement performed with a standard sphygmomanometer as well as the digital signal obtained during the CNBP measurement (1-3 min)
• Based on the CCTA description or meta data contained in the imaging data the doctor or another member of the study team will record the following information in the CRF:

• Radiation dose during CCTA
• Contrast medium dose during CCTA
• Will enter the following information in the CRF:

• Radiation dose during the diagnostic part of ICA
• Contrast medium dose during the diagnostic part of ICA
• Number and type of adverse events
• Duration of the diagnostic workup.

Stage 4

Within 7 days of entering all the stage 3 data the investigator (a cardiologist) trained by the sponsor will measure the value of the virtual FFR with the Cardiolens FFR-CT Pro system at locations corresponding to ICA FFR measurements (based on video recording entered in the database during stage 2)

Based on results obtained from the Cardiolens FFR-CT Pro system vs reference data an analysis will be performed on meeting the primary and secondary end points of the trial.

Inclusion criteria

• Age ≥ 18
• Declaration of informed consent to sharing medical records gathered during the standard diagnostic workup
• History of chronic coronary syndromes (CCS)
• Diagnostic CCTA (good quality test allowing investigation of the entire coronary artery tree), showing at least one site with stenosis ≥50% of the lumen in a large coronary artery of ≥ 2 mm diameter, with no prior revascularisation
• Standard treatment of chronic coronary syndromes with no dosage modification required within at least 4 weeks before the enrolment
• Patients with a prior acute coronary syndrome (ACS) or revascularisation would be found eligible under the following conditions:

• Over 30 days from the acute coronary syndrome occurrence
• FFR assessment during ICA may only cover the vessels that were not revascularized (both PCI and CABG) and were not the reason of ACS
• No closed coronary arteries

Exclusion criteria

• CCTA-confirmed myocardial bridges causing >50% stenosis of the epicardial vascular lumen
• Coronary obstruction confirmed by CCTA or invasive coronarography
• History of ACS with coronary angioplasty or Coronary Artery Bypass Grafting (CABG) performed unless point 6 conditions are met
• Significant haemodynamic abnormalities of the valve or history of surgical correction of the defect or CABG
• Second-degree or third-degree atrioventricular block, sinus node dysfunction, QTc > 450 ms or prolonged QTc
• LVEF ≤ 35% found in an echocardiogram performed within the last 6 months
• BMI ≥ 35
• Clinically apparent infection
• Thrombocytopenia below 100.000/mm3
• Active neoplastic disease (apart from basal cell carcinoma and carcinoma in situ) and other conditions, which, in the investigator's opinion significantly affect their life expectancy
• Other significant conditions, infections, addictions and psychological or social factors, which, in the doctor's opinion, may affect patient's ability to participate in the trial or significantly affect their safety