Department of Imaging DiagnosticNational Cardiovascular Hospital, Sofia

E.Valcheva

Why Image Post CABG

Early and late graft disease- Up to 12% of vein grafts occluded before discharge- 50% of vein grafts occluded at 10 years- 17% of mammary artery grafts occluded at 10 years

Disease progression in non grafted arteries- 40% over 10 years

Pre-op evoluation for CABG reoperations

Why MDCT

• Advanced age

• Generalized atherosclerotic disease

• Comorbidity

• Risk of angiography is higher

Indication for MDCT after CABGs

Asymptomatic patients

Patients with atypical chest pain

Patients with mismatching stress test (ECG and nuclear medicine)

CT Assessment After CABGs

Graft anatomy- Shape and borders of the vessel

- To distinguish side of the anastomosis

- Measurement of bypass diameter

Distal anastomosis

Origin LIMA

Distal Vessels

CT Assessment After CABGs

Graft anatomyPatency

CT Assessment After CABGs

Graft anatomyPatencyStenosis /OcclusionProgression of disease in

native coronary arteries

LAD

Detection of Native Coronary Artery Stenosis by CT After CABG

Study CTPatients, n

Excl,%

Sens,% Spec,% PPV,% NPV,% Acc,%

Nieman et al 4 24 31,34 90,79 75,72 81,73 86,79 83,76

Stauder etal 16 20 31 92 77 86 85 87

Salm et al 16 25 26 100 89 85 100 93

Malaguitti et al

64 52 0 92 71 65 99 81

Ropers et al 64 50 9 86 76 44 96 73

CT Assessment After CABGs

Graft anatomyPatencyStenosis /Occlusion- More common SVG- IMA rare more

common when grafted vessel narrows

CT Assessment After CABGs

Graft anatomyPatencyStenosis /Occlusion

Graft aneurysm formation- Pseudoaneurysms occur

at anastomoses- True aneurysms occur

mid-graft, >5yrs

CT Assessment After CABGs

Graft anatomyPatencyStenosis /OcclusionProgression of disease in

native coronary arteriesReoperation PlanningMyocardial function and

morfology (thickness, thickening and perfusion) EF – 41%; EDV – 288

ml; ESV – 169 ml; SV -110 ml; CO – 7.31/min.

CT Assessment After CABGs

Graft anatomyPatencyStenosis /OcclusionProgression of disease in

native coronary arteries

Reoperation Planning

MDCT Diagnostic Accuracy in Evaluating all CABG and Native Postanastomotic Coronary Arteries

CABG Native CpronaryArteries

Sensitivity,% 100% 100%

Speciiicity,% 98,5% 97,7%

PPV,% 96,5% 86%

NPV,% 100% 100%

Accuracy of MDCT in CABG Evaluation

Follow – up of Patients After Percutaneous Coronary Intervention

Types of artifacts related to stents

Stent type artifacts Stent strut thickness

Stent analysis

Total Stents Detectable Stents

Interpretable Lumen in Detectable Stents

Stent Location

LAD 64 58(91%) 15(55%)

LCx 63 32 (82%) 28 (44%)

RCA 75 52 (69%) 35 (47%)

SVG 6 6(100%) 6 (100%)

Stent diameter,mm

2,5 42 35 (83%) 12 (34%)

3,0 86 69 (80%) 40 (58%)

3,5 61 51 (84%) 41 (80%)

4,0 42 34 (81%) 28(82%)

4,5 1 1 (100%) 1 (100%)Gilard,M et al, Heart 2006,70

Comparison of the Different Reconstruction Protocols

RCA In - Stent Restenosis

LAD Stent

LAD Stent

LAD In - stent Restenosis

Diagnostic Accuracy of Multidetector CT to Detect In –stent Restenosis

All Patients Simple Stenting

ComplexBifurcation

stenting

Total, n 70 46 24

True negatives, n

55 39 16

True positives, n

10 6 4

Falsenegatives, n

0 0 0

False positives, n

5 1 4

Sensitivity, % 100(72-100) 100 (61-100) 100 (51-100)

Specificity, % 91 (82-96) 98 (87-99) 80 (58-92)

Accuracy, % 93 (84-97) 98 (89-99) 83 (64-93)

PPV, % 67 (42-85) 86 (49-97) 50 (22-78)

NPV, % 100 (93-100) 100 ( 91-100) 100 (81-100)Van MieghemCA,CademartiriiF, et al. Circulation 2006,114

MDCT may be an adequate modality for patients undergoing LM/LAD arteries intervention with stenting.

Stent in Bypass Conduits

CORE - 64Sensitivity 33,3 %

Specificity 91,7 %

PPV 57,1 %

NPV 80,5%

Accuracy 77,1 %

CONCLUSION. The results of our study showed that 64 –MDCT has poor ability to detect in – stent restenosis in small – diameter stents. Thus,64 – MDCT may be appropriate far stent assesment in only selected patients.

AJR:194, January 2010

National Cardiovascular Hospital

Thank you for attention