Background: the decision-making process of patients with angiographically-intermediate coronary lesions (ICL) is clinically challenging and may benefit from adjunctive invasive techniques. Fractional-flow-reserve (FFR) represents the gold standard to evaluate ICL but optical-coherence-tomography (OCT) is a novel, promising, high resolution coronary imaging technique.

Objectives:

1. Investigate the relation between OCT and FFR parameters in ICL and understand if OCT measures may predict FFR.
2. Understand if OCT parameters may predict clinical outcome of patients with ICL not underwent revascularization on the bases of negative FFR.

Study design: multicentre, international, individual patient's level data pooled analysis.

Principal investigators that enrolled stable or unstable patients with ICL who underwent both FFR and OCT assessment of the same lesion, will be contacted to participate the study. Agreeing investigators will be asked to complete a structured database by providing a series of key baseline clinical and angiographic data, OCT and FFR parameters.

Collected dataset will include: sex, age, hypertension, diabetes, hypercholesterolemia, current smoking, family history of CAD, clinical presentation, previous PCI, previous MI, previous CABG, non-invasive ischemia, angina, n° of diseased vessels, diseased vessel, percentage diameter stenosis at quantitative coronary angiography (QCA% stenosis), length of stenosis at quantitative coronary angiography, presence of thrombus or ulceration, MLA, area stenosis at OCT, FFR protocol (intracoronary adenosine, endovenous adenosine, contrast) results and long term clinical follow-up.

Inclusion Criteria:

• Patients with angiographically-intermediate coronary lesion
• Patients who underwent both FFR and OCT assessment of the same lesion

Stable or unstable patients with intermediate coronary lesions who underwent both FFR and OCT assessment of the same lesion