Recently, a new device for measuring physiological lesion severity, the pressure microcatheter, was introduced. The pressure microcatheter provides similar information to the conventional measurement technique but differs as it is easily advanced on a customary coronary wire and simplifies pullback maneuvers. The pressure microcatheter has been shown to provide comparable FFR results to pressure wires.

Insightful-FFR is an investigator-driven, multicenter, randomized, open-label and prospective trial of patients with stable coronary artery disease or stabilised non-ST elevation acute coronary syndrome (ACS) with epicardial stenosis considered for PCI aiming at comparing clinical outcomes between pressure microcatheter and pressure wire-guided strategies. The study hypothesis states that the use of a Pressure Microcatheter for clinical decision making would be non-inferior to pressure wire-based strategy

After determining the presence of a coronary artery disease/ stabilized acute coronary syndrome, patients will be randomized to use a pressure microcatheter (investigational device) or a pressure wire (comparator) to guide and optimize percutaneous coronary intervention (PCI). Patients will be followed up in hospital at 12 months and yearly until five years.

Inclusion Criteria:

1. The subject must be at least 18 years of age and younger than 85 years old.
2. Eligible for elective PCI.
3. Stable angina or ACS (non-culprit vessels only and outside of primary intervention during acute STEMI)
4. Subject willing to participate and able to understand, read and sign the Informed Consent.

Exclusion Criteria:

1. STEMI as clinical presentation.
2. Chronic total occlusion as a target vessel.
3. Significant contraindication to adenosine administration (e.g. heart block, severe asthma)
4. Uncontrolled or recurrent ventricular tachycardia.
5. Hemodynamic instability.
6. Severe valvular disease.
7. Severe renal dysfunction defined as an eGFR ≤30 mL/min/1.73 m2.
8. Comorbidity with life expectancy ≤ 2 years.
9. Inability to take DAPT (both aspirin and a P2Y12 inhibitor) for at least 12 months in the patient presenting with an ACS, or at least six months in the patient presenting with stable CAD, unless the patient is also taking chronic oral anticoagulation in which case a shorter duration of DAPT may be prescribed per local standard of care.
10. Planned major cardiac or non-cardiac surgery within 24 months after the index procedure. Note: major surgery is any invasive procedure in which an extensive resection is performed, e.g., a body cavity is entered, organs are removed, or normal anatomy is altered. Note: minor surgery is an operation on the superficial structures of the body or a manipulative procedure that does not involve a serious risk. Planned minor surgery is not excluded.
11. Subject has known hypersensitivity or contraindication to any of the study drugs (including all P2Y12 inhibitors, one or more components of the study devices, including everolimus, zotarolimus, biolimus, sirolimus, cobalt, chromium, nickel, platinum, tungsten, acrylic, and fluoropolymers, or radiocontrast dye that cannot be adequately pre- medicated.
12. The subject has received a functioning solid organ transplant or is active on a waiting list for any solid organ transplants with expected transplantation within 24 months.
13. The subject receives immunosuppressant therapy or has known immunosuppressive or severe autoimmune disease that requires chronic immunosuppressive therapy (e.g., human immunodeficiency virus, systemic lupus erythematosus, etc.). Note: corticosteroids are not included as immunosuppressant therapy.
14. The subject has previously received or is scheduled to receive radiotherapy to a coronary artery (vascular brachytherapy) or the chest/mediastinum.
15. Subject has a platelet count <100,000 cells/mm3 or >700,000 cells/mm3.
16. The subject has a documented or suspected hepatic disorder defined as cirrhosis or Child-Pugh ≥ Class B.
17. The subject has a history of bleeding diathesis or coagulopathy or has had a significant gastro-intestinal or significant urinary bleed within the past six months. The subject has had a cerebrovascular accident or transient ischemic neurological attack (TIA) within the past six months, any prior intracranial bleed, any permanent neurologic defect, or any known intracranial pathology (e.g., aneurysm, arteriovenous malformation, etc. The subject has a life expectancy of <2 years for any non-cardiac cause.
18. The subject is currently participating in another investigational drug or device clinical study.
19. Pregnancy or nursing.
20. Presence of other anatomic or comorbid conditions or other medical, social, or psychological conditions that, in the investigator's opinion, could limit the subject's ability to participate in the clinical investigation or to comply with follow-up requirements or impact the scientific soundness of the clinical investigation results.