The aim of this study is to establish the diagnostic performance of the AngioAI+ System (AngioInsight, Inc, USA) for estimating:

1. Fractional flow reserve (FFR) and
2. Detection of coronary microvascular disease (CMD)

SMARTFLOW is a prospective, single-arm, observational multicenter study of patients with suspected coronary artery disease (CAD) undergoing clinically indicated invasive coronary angiography with physiological assessment. The study is designed to prospectively enroll patient cohorts and collect data according to their reference procedures (e.g. FFR, CFR measures). A core lab will evaluate performance of the AngioAI+ software retrospectively using the collected SMARTFLOW study data. As such, the investigational AngioAI+ device will not inform clinical decisions amid the study procedure.

All patients will undergo clinically indicated invasive coronary angiography with physiological assessment according to standard of care.

Cohort 1: Patients with intermediate lesions (30-90% diameter stenosis) will undergo invasive FFR assessment. In patients with FFR >0.80 (non-flow limiting stenosis), subsequent assessment of the microcirculation with bolus and continuous thermodilution will be performed.

Cohort 2: Patients with non-obstructive (<30% stenosis) disease will undergo assessment of the microcirculation with bolus and continuous thermodilution.

For patients in Cohort 1 with FFR ≤0.80 undergoing percutaneous coronary interventions (PCI), FFR measurements after PCI will be recommended. Use of intravascular imaging will be strongly encouraged to guide PCI procedures, in accordance with current practice guidelines.

Inclusion Criteria:

• Patients with acute or chronic coronary syndromes referred for invasive coronary angiography with clinically indicated coronary physiologic assessment. In patients with acute coronary syndromes, the physiological evaluation will be restricted to non-culprit vessels.
• Patients with intermediate CAD (30-90% visual stenosis) with clinically indicated FFR assessment.
• Patients with NOCAD (<30% visual stenosis) with clinically indicated microvascular assessment.

Exclusion Criteria:

• Patients presenting with ST-elevation
• Prior myocardial infarction in the target vessel
• Stent implantation in the target vessel within the last 12 months
• Previous coronary artery bypass grafting surgery (CABG)
• Previous heart valve surgery
• Previous heart transplantation
• Moderate-to-severe valvular disease
• Left ventricular ejection fraction (EF) ≤45%
• Hemodynamic instability or cardiogenic shock

Angiographic Exclusion Criteria

• Left main stenosis≥50%
• Chronic total occlusion in the target vessel
• CTO in a non-target vessel
• Less than thrombolysis in myocardial infarction (TIMI) 3 flow in the target vessel
• Target vessel receiving collaterals
• Inadequate coronary angiographic images
• Ostial lesions
• Severe tortuosity

Patients with acute or chronic coronary artery disease

Decision regarding IPD sharing will be made in the future.