| Inclusion criteria | |
| Patients presenting for ACS who underwent IVUS during diagnostic interventions IVUS run carried out for borderline lesions evaluation (no tight stenosis). IVUS run included segment of interest (lesion) and at least one reference vessel segment IVUS run considered suitable for analysis with automatic pull back | |
| Exclusion criteria | |
| IVUS run carried out for the evaluation of a stent, acutely or previously implanted IVUS run not including at least one of the two reference segments IVUS run with manual pull back IVUS run with >40% superficial arc of calcification on more than 50% of lesion length IVUS run interrupted by side branches >1.5 mm in diameter IVUS run considered inadequate technically | |