1. Stenotic atherosclerotic coronary artery disease
Satya Shanbhag
Waikato Cardiothoracic Unit

2. Definition
Stenotic atherosclerotic coronary artery disease (CAD) is narrowing of the coronary arteries caused by thickening and loss of elasticity of their walls (arteriosclerosis) that, when sufficiently severe, limits blood flow to the myocardium.

4. Etiology Increasing age Diabetes and high lipids Renal disease HTN
Smoking
Strong family history
Sedentary lifestyle, high stress and dietary habits

5. Atherosclerotic process
Lipoid foci are associated with or converted into plaques of fibrous or hyaline connective tissue
Fibrolipoid plaques may become thick enough to encroach on the lumen of the artery, producing a stenotic lesion
Gradual regression of plaque enlargement and development of collateral coronary blood flow can result in at least partial spontaneous restoration of antegrade regional myocardial blood flow.

7. Types of plaque progression
Plaque rupture
Plaque erosion
Age
All age, 35-80
30-50
Gender
Male > Female
Male = female
Inflammation
Macrophages
Lymphocytes
Risk factors
Hyperlipidemia, DM, smoking, genetic
Smoking, genetic
Incidence of sudden death
25-30%
70-75%
Types of plaque progression

8. ACS pathology
Fissuring, or rupture, of atherosclerotic plaques is the genesis of the acute coronary syndromes termed unstable angina and acute MI
Coronary stenosis that produce less than 50% reduction in lumen diameter are often the site of the atherosclerotic plaque rupture
Rupture is through the cap of the plaque, and areas in which the cap lacks underlying collagen support seem particularly vulnerable

9. Types of coronary artery disease
Stable ischemic heart disease (stable angina)
Acute coronary syndromes
1) Unstable angina/ Non- ST segment MI(NSTEMI)
2) ST segment elevation MI (STEMI)

10. Diagnosis Symptomatology and initial ECG’s Coronary angiogram
Coronary intravascular ultrasound
CT coronary angiogram
Fractional flow reserve
Echocardiogram
CMR

11. Coronary anatomy-angiogram
Left coronary artery: Includes the left main, LAD and the circumflex system. The LAD has one or more diagonal branches whereas the Cx has one or more obtuse marginal arteries

12. Left coronary artery: Surgeons view showing the LAD system with diagonal artery.

13. Left coronary artery: Spider view showing the LAD system on left and circumflex artery. Good view to see intermediate artery.

14. Right coronary artery: RCA with the posterior descending (PDA) and posterior-lateral (PLA).

15. Intramyocardial LAD artery: Intramyocardial LAD can cause step defect with stenosis. Also difficult to create anastomosis.

16. Fractional Flow Reserve (FFR)

17. Echocardiogram

18. CTCA

19. CMR and isotope study

20. Management- CABG

21. Important trials/randomised studies
SYNTAX trial: Showed CABG is superior to PCI in multi-vessel and LMA disease
FREEDOM trial: Showed CABG to be superior to PCI in diabetics

22. SYNTAX Trial
Synergy between PCI with Taxus and coronary surgery ( )
1800 patients in total: PCI or CABG
MACCE(major cardiac and cerebrovascular event) calculated
Death and stroke not different between groups at 1 yr but significantly higher at 5 yrs with PCI
Also, PCI group had increased incidence of MI, required more revascularisation

23. AHA Guideline 2014

25. Stable ischaemic heart disease
Class I indication: significant left main disease (>50%), left main equivalent disease (proximal stenosis of at least 70% of LAD and circumflex), triple vessel disease (patients with LVEF <50% or large area of myocardium at risk) and proximal LAD disease with LVEF between 35-50%

26. Stable ischaemic heart disease
Class IIa indication: significant left main disease (>50%), left main equivalent disease (proximal stenosis of at least 70% of LAD and circumflex), triple vessel disease (patients with LVEF <50% or large area of myocardium at risk) and proximal LAD disease with LVEF between 35-50%

27. ACS: unstable angina/NSTEMI
Indication is anatomically identical to stable disease
In UA/NSTEMI, achieving revascularisation creates a stronger motive in preventing death
Indication for CABG further strengthened by acuity of presentation, degree of ischaemia and benefit of full revascularisation

28. ACS: STEMI
Mainstay of treatment is through primary PCI and IV thrombolysis
CABG in acute setting: ongoing ischaemia, cardiogenic shock, failure of optimal medical management including IABP
Other indications: failed PCI/thrombolysis, large area at risk, unsuitable anatomy for PCI, LMA disease, life threatening arrhythmia (ischaemic origin), mechanical complication such as IMR, wall rupture

31. CABG: Operative technique

32. CABG: Operative technique

33. Conduits used (LITA/LIMA)

34. SVG

35. Radial

37. CABG: long term graft patency

38. Long term prognosis of CABG
Prevent sudden death
Reduce long term death (96%,90%, 76% and 56% at 1, 5, 10 and 15 years)
Freedom from cardiac events
Improve left ventricular function
Improve functional quality

39. Functional status and quality of life
Functional status improves markedly and may equal normal matched control population
Sub-optimal/ worsening status: female, DM, smokers, low socioeconomic population, HTn, low ejection fraction
Improvement starts from 3 months and improves up to 12 years

40. Advances TMLR MIDCAB (minimally invasive direct coronary bypass)
Robotically by TECAB- can be used for multivessel disease

42. Summary CAD is the largest cause of disability & death
Atherosclerotic disease and lifestyle changes are the main cause
Coronary angiogram mainstay of diagnosis
PCI or CABG employed for definitive treatment
No other operation has prolonged more lives, provided more symptom relief than CABG
Minimally invasive revascularation strategies evolving

43. Questions

44. TITLE
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