1. Qu Xinkai Shanghai Chest Hospital Shanghai Jiaotong University Value of comprehensive cardiac evaluation using MSCT in patients with CTO

2. 3,277 STEMI pts treated with PCI; Three groups: SVD; MVD without CTO; MVD with a C TO in a non-IRA The presence of a CTO is associated with reduced LVEF and further deterioration of LVEF. Claessen. J ACC Intv 2009 Long-term mortality and LVEF of CTO

3. 124 CTOs with DES;159 CTOs with BMS Felice. JACC Intv 2009 After 3 yrs, DES were superior to BMS in reducing MACE in pts with CTO and should be considered the preferred treatment strategy CTO 3yrs FU: DES vs BMS

4.  Comprehensive cardiac assessment is necessary before revascularization is performed, so that the patients most suited for PCI can be selected.  CTO lesion;  Myocardial viability

5.  Inability to cross the lesion into the true lumen of the distal vessel with a guide wire (>60%);  Intimal dissection with creation of a false lumen;  Contrast extravasation;  Failure to cross the lesion with a balloon;  Failure to dilate adequately Reasons for procedural failure of PCI for CTO

6.  Most important predictors  Severe calcification at the stump of CTO  Tortuosity of the proximal vessel of CTO  Very long occlusion length  Other predictors for less-experienced operators  Absence of antegrade flow and no or poor distal vessel visibility  Long occlusion duration  Presence of antegrade bridging collaterals (reflection of chronicity of the lesion)  Blunt stump occlusion  Presence of side branch at occlusion site Predictors of procedural failure

7. Mowatt G, etal. Heart 2008;94:1386-1393 CTCA: meta-analysis (28 trials)

8. A ： MPR B ： 3D-VR-Tree C ： 3D-VR-Outline D ： 3D-VR-Heart

9. The CTCA suggests PCI will be more difficult because of the absence of any clear stump, moderately long total occlusion, and poor distal vessel quality, PCI was not successful in the recanalization of the RCA CTCA to CTO

10. the duration of the patient’s symptoms was for a few weeks, represents sub-acute occlusion and not a CTO CTCA to CTO: MPR and 3D-MIP images

11. Assessment of tortuosity by MSCT Garcia-Garcia. EuroInterv 2009

15. Hsu. IJC 2009

17.  Route and course of CTO segment, as the distal vessel can be well visualized usually.  Length and diameter of the occluded segment without foreshortening. 3D-length measurement of occlusion is possible by CTCA even if retrograde or collateral contrast filling is poor or absent at catheterization  MP and 3D views allow planning of the best angiographic view of the occlusion trajectory during PCI, i.e., 3D-roadmapping fusion with catheterization laboratory data may be possible What could we learn from CTCA for CTO

18.  Presence of calcification at the stump of occlusion, especially severe or concentric calcification—this may assist in selection of targeted strategy, e.g., upfront use of ablative technique  Presence of proximal tortuosity at the occlusion site  Presence of blunt occlusion stump or a side branch at the occlusion site  Collaterals or bridging vessels at the occlusion site are not usually visualized by CTCA; septal collaterals cannot be demonstrated by CTCA due to their intramyocardial location What could we learn from CTCA for CTO

19. Reconstruction of image from MSCT scanning

20. Henneman. Am J Cardiol 2008 69 pts with MI > 3 m SPECTNormal (N)Infarct (MI) MSCT N40 MSCT MI362 Healed MI can be detected accurately using MSCT, with good correlation with SPECT MSCT vs SPECT to healed MI

21. 15 pigs with reperfusion after MI, 6months A DE-MDCT provides a more detailed assessment of the PIZ in chronic MI and is less susceptible to partial volume effects than MRI. Schuleri. JACC 2009

22. White arrows: enhanced scar tissue White circle: peri-infarct zone (PIZ)

23. 1 min5 min10 min15 min20 min MI volume (%) 11.87±3.549.78±2.88*9.57±2.88* 8.99±2.69* † #8.51±2.93* † # CT value of infarcted region (HU) 26±1568±11*66±6*64±7*69±18* CT value of cavity (HU) 620±39383±26* 302±27* † 245±25* † #232±22* † # CT value of normal myocardium (HU) 253±32179±23*150±10* 129±5* † #128±20* † # Volume of infarction (percentage) and CT value of different cardiac tissues at various time-points

24. Comparison of MI size between TTC staining and MSCT using Bland-Altman plots at various time- points

25.  Features of the CTO artery could be assessed using CTCA;  Infarct size and viable myocardium could be assessed using MSCT;  Comprehensive cardiac information for CTO could be afforded using only a single MSCT examination.  The data would be helpful for selection of patients with CTO for revascularization. Conclusion

26.  Due to exposure of patients to X-rays and potentially toxic contrast agents, MSCT perfusion imaging is unlikely to become a first-line test to assess myocardial viability in all patients. Until now, this modality has only been recommended for use in patients with definite CTO or previous MI.  It is still difficult and time-consuming to analyze the myocardial perfusion images. With the development of dedicated software, the problem of the heavy workload could be diminished in the future. Clinical limitations