Coronary artery disease remains a leading cause of mortality worldwide and is commonly treated with percutaneous coronary intervention (PCI). Typically, PCI is guided by invasive coronary angiography (ICA). However, ICA has inherent limitations in accurately assessing vessel dimensions, calcium burden, circumferential tissue and whether a stent has achieved full expansion. Therefore ICA alone is insufficient for guiding stent optimization, especially in complex lesions which are most vulnerable to long-term stent failure. To overcome the limitations of ICA, intracoronary imaging can be used to guide and optimize PCI. The advantages of intracoronary imaging include obtaining larger lumen areas, better stent expansion and strut apposition, full lesion stent coverage and identifying stent complications. Multiple randomized studies have shown that these advantages translate into a reduction in major adverse cardiovascular events (MACE) in complex PCI. Consequently, the recommendation for intracoronary imaging has been upgraded in the most recent guidelines.

Despite robust evidence supporting its benefits, intracoronary imaging remains relatively underused in real-world practice and in the Netherlands it is only used in 7% of complex PCI procedures. This underutilization may be attributed to several factors, including operator and hospital-dependent issues such as lack of experience, reluctance to spend additional time on intracoronary imaging and concerns about its cost-effectiveness. Therefore, initiating an implementation project to incorporate intracoronary imaging into routine use in the catheterization lab during complex PCI would be highly valuable. Such a project could make imaging-guided PCI the standard of care in complex PCI. Additionally, it could evaluate the cost-effectiveness of routine intracoronary imaging during complex PCI.

For this reason we designed the OPTIMIZE-PCI II, a national registry-based quality improvement project. This project is aimed at implementing a liberal intracoronary imaging-guided strategy for complex PCI across multiple centres in the Netherlands, with data extraction from the Netherlands Heart Registration (NHR) database. The objective of the OPTIMIZE-PCI II is to establish a routine use of intracoronary imaging in complex PCI, to determine if this approach reduces adverse cardiac events in real-world practice, and evaluate its cost-effectiveness.

Design and outcomes measures will be discusses elsewhere. Additional information: Patients in this observational, registry study, will be included by the Netherlands heart registration (NHR). The NHR is an independent organization in which Dutch hospitals prospectively register standard sets of baseline, procedural and outcome data for all invasive cardiac procedures, including PCI. Data provided to the NHR are extensively checked on completeness and quality, reviewed with audit reports by independent trained research nurses and discussed by cardiologists in registration committees. Multiple audits are conducted annually by the NHR for data validation and verification. A waiver for informed consent for analysis with the data of the NHR data registry is obtained.

This study will be a quality improvement project.

Inclusion Criteria:

• All patients above the age of 18, included in the Netherlands Heart Registration (NHR) quality database after receiving PCI in complex coronary lesions, will be included in the analyses of this project.

• Meeting one or more of the following complexity criteria:

  • Left main: A stenosis of >50% and/or a FFR ≤ 0.80 and iFR ≤ 0.89 in the left main.

  • Severely calcified lesion: Defined as use of calcium modification therapy (e.g. cutting balloon, scoring balloon, rotablation, orbital atherectomy, intravascular lithotripsy).

  • Chronic total occlusion: Coronary CTO is defined as an obstruction of the coronary artery with the following classic lesion characteristics:

    • TIMI flow 0
    • Absence of contrast stasis at the site of the proximal capillaries
    • Presence of collateral vessels
    • Estimated occlusion duration of at least 3 months.

  • Ostial lesion: Lesion at the origin (within 5 mm) of a major coronary vessel (LM, LAD, RCX and RCA).

  • Long lesion: A vessel treated with one or multiple stents with a total stent length of ≥38 mm is considered a long lesion.

  • Bifurcation (true): A coronary artery narrowing occurring adjacent to, and/or involving, the origin of a significant side branch ≥ 2.5mm. Only true bifurcation will be included, i.e. medina 1,1,1/1,0,1/0,1,1.

  • In-stent restenosis: A reduction ≥50% of the luminal diameter within the previously stented segment or the vessel segments 5 mm proximal and distal to the stent (the "stent edges"), as assessed by coronary angiography.

Exclusion Criteria:

- Non complex PCI

The population exists of patients registered in our national PCI registration of the Netherlands Heart Registration after receiving complex PCI. All indications are included (ACS and non-ACS, OHCA, cardiogenic shock).