PCI will be optimized according to the IVUS. IVUS will be performed before PCI and will be used to select PCI strategy.

Operators will try to reach an optimal anatomical PCI result as assessed by IVUS aiming for the following criteria:

1. good stent apposition;
2. good stent expansion (minimal stent area (MSA) >90% of distal reference lumen area and/or MSA ≥5.5mm2);
3. plaque burden 5mm proximal and distal to the stent <50%);
4. no stent edge dissection.

After stent optimization an IVUS run will be performed. The IVUS run will be considered as final when further anatomical optimization will not be thought to be possible.

The goal will be to achieve the optimal functional result, defined as an FFR post PCI ≥ 0.95. Further stented segment post-dilatation will be mandatory if FFR post PCI < 0.95. In case of a clear evidence of significant atheroma proximal or distal to the stented segment, the operators will be encouraged to optimize the functional result further by implanting additional stents.

PCI to long lesion will be optimized according to the IVUS.

Post PCI FFR value < 0.9

Post PCI FFR value ≤ 0.8

If all the four following IVUS criteria met: (1) good stent apposition; (2) good stent expansion (minimal stent area (MSA) >90% of distal reference lumen area and/or MSA ≥5.5mm2); (3) plaque burden 5mm proximal and distal to the stent <50%); (4) no stent edge dissection.

Composite endpoint (target vessel related death (TV-death), target vessel related myocardial infarction (TV-MI), any target vessel revascularization (TV-R))