Computed Tomography Coronary Angiography Before Stent Implantation

• Minimal in stent lumen area as assessed by IVUS [ Time Frame: Up to 10 minutes after stent implantation ] [ Designated as safety issue: No ]
  
• Adequacy of lesion coverage defined as minimal lumen area in reference segments adjacent to stent shoulder. [ Time Frame: Up to 10 minutes after stent implantation ] [ Designated as safety issue: No ]
  

• Mean stent lumen area [ Time Frame: Up to 10 minutes after stent implantation ] [ Designated as safety issue: No ]
  
• Mean lumen area and plaque and media area in 10mm segments adjucent to stent edges. [ Time Frame: Up to 10 minutes after stent implantation ] [ Designated as safety issue: No ]
  
• Qualitative and quantitative assessment of potential complications (tissue prolaps, plaque shift, stent edge dissection and stent malapossition) [ Time Frame: Up to 10 minutes after stent implantation ] [ Designated as safety issue: No ]
  

Currently most percutaneous coronary interventions (PCI) are planned and performed on the basis of invasive coronary angiography which provides the information that is confined to the vessel lumen. This limitation may be partially responsible for the unfavorable long term outcome and complications that occur in some patients. Additional information on the disease burden in angiographically normal coronary segments adjacent to the lesion site could impact the treatment strategy and clinical results. Imaging modalities that allow not only lumen but also vessel wall assessment include both invasive (e.g. intravascular ultrasounds - IVUS) and non-invasive (e.g. multislice computed tomography - MSCT) methods. IVUS guidance of the coronary interventions is expensive and given its invasiveness is related to the additional risk. The number of patients who are referred for coronary angiography with significant stenosis diagnosed with MSCT is rapidly increasing. Most interventional cardiologists are not familiar with coronary vessel images produced by MSCT. The aim of our study is to assess if the analyses of MSCT images before the PCI may impact the treatment strategy and immediate results. The study will enroll subjects with significant coronary stenosis diagnosed with MSCT who are referred to the catheterisation laboratory for invasive angiography and PCI. The study participants will be randomized into two groups:

Group 1 - the results of MSCT are analysed by the interventional cardiologist that is to perform angiography and PCI. Based on this analysis preliminary procedural strategy is planned (stent diameters, decision on direct stenting vs. predilatation, decision on postdilation) Group 2 - interventional cardiologist is blinded to the images obtained by MSCT. The PCI procedure is performed solely on the basis of invasive coronary angiography In both study groups IVUS will be performed before and after stent implantation. The operator will be blinded to the results of pre-PCI IVUS. The second IVUS will be performed when angiographic results are optimal in the opinion of the operator. The results of the second IVUS examination will be the efficacy measure of the two compared treatment strategies.