Surgery of Coronary Artery Disease

1. Surgery of Coronary Artery Disease

2. Ischemic Heart Disease • IHD – imbalance between myocardial oxygen demand and supply: • Coronary Artery Disease • Printzmetal Angina • Syndrome X

3. Coronary Artery Disease (CAD) Deficiency in blood supply to myocardium caused by stenotic atheromatous lesions in major branches of coronary arteries

4. Clinical Forms of CAD • Stable Angina • Unstable Angina • Acute Coronary Syndrome • Myocardial Infarction • Ischemic Myocardiopathy (Left Ventricular Remodeling, Mitral Regurgitation)

5. Prevalence of CAD • About 50% of total mortality in Europe and North America is due to cardiovascular diseases • 100.000 of Acute Myocardial Infarctions in Poland each year • The older population the more prevalent CAD

6. Complex Etiology of Atheromatosis • Genetic (family history) • Metabolic (hyperlipidemia, diabetes) • Life Style (obesity, smoking, lack of exercise) • Infectious and Inflammatory?

7. Risk Factors of CAD • Sex - male • Age - older • Family History • Arterial Hypertension • Hyperlipidemia • Smoking • Obesity

8. Symptoms of CAD (1) • Angina – retrosternal chest pain, usually related to the exercise • Canadian Cardiovascular Society (CCS) Classification of Angina: • I class – only in extreme exercise • II class – in moderate exercise • III class – in every exercise • IV class – also in rest

9. Symptoms of CAD (2) • Dyspnea (in Ischemic Myocardiopathy or Mitral Regurgitation) • New York Heart Association (NYHA) classification of dyspnea (I-IV class) • When NYHA class higher than CCS class – poor prognosis

10. Pathology of CAD (1)

11. Pathology of CAD (2)

12. Pathophysiology of CAD Consequences of Coronary Artery Stenosis: • Up to 50% - asymptomatic • About 75% - exercise angina • More than90% - rest angina • 100% - AMI

13. Diagnostics of CAD

14. Evidence taken from Exercise ECG • Clinically positive (angina) • ECG positive (ST segment abnormalities)localization: anterior, lateral, posterior • Exercise tolerance (in METs*)* MET – metabolic equivalent – rest oxygen demand = 30 ml/kg/min

15. Evidence taken from Echocardiography • Global systolic function of left ventricle – left ventricular ejection fraction (LVEF): • Good – LVEF>50% • Moderately impaired –LVEF 30-50% • Poor –LVEF<30% • Regional systolic abnormalities (hypokinesis, akinesis, dyskinesis) • Mitral Regurgitation

16. Indications for Coronary Angiography • Typical Angina (even with negative ECG exercise test) • Positive ECG exercise test • Unstable Angina / Acute coronary syndrome (primary rescue PCI) • After Myocardial Infarction especially when angina persists

17. Technique of Coronary Angiography • Selective coronary artery catheterization via femoral or radial artery • Administration of iodine contrast • X-ray motion picture

18. Evidence taken from Coronary Angiography • Presence of lesions in coronary arteries • Degree of stenosis (0-100%) • Localization of lesions (proximal or distal) • Type of lesions (A, B or C)

19. What is a significant stenosis of coronary artery? • Left main stem (LMS) stenosis of 50% or more • Other vessels stenosis of 75% or more

20. Clinical Value of Coronary Angiography in Decision Making

21. Invasive Cardiology or Surgery?The most important disadvantage of PCI is still high rate of re-stenosis, reaching 30% per year (10% using DES)

22. Anatomy of Coronary Arteries

23. Anatomy of Left Coronary Artery

24. Anatomy of Right Coronary Artery

25. The Milestones of Coronary Surgery • 1959 Sonnes Coronary angiography • 1964 Kolesov Graft:LITA-LAD (no CPB, no Angiography) • 1967 Favaloro CABG • 1991 Benetti OPCAB

26. Idea of Surgical Treatment of CAD Revascularization of the heart via by-passing significantly narrowed coronary arteries to enhance blood supply to ischemic regions of myocardium

27. The Goals of Surgery in CAD • To prolong a lifetime • To improve a quality of living • To prevent myocardial infarction and its complications

28. Surgical Revascularization Procedures • Coronary Artery By-Pass Grafting (CABG) - CLASSIC • Off-Pump Coronary Artery By-Pass (OPCAB) – NO CPB • Minimally Invasive Coronary Artery By-Pass (MID-CAB) – NO STERNOTOMY • Transmural Laser Revascularization (TMLR) - ALTERNATIVE

29. CABG – The Classic Coronary Operation Since 1967 when Favaloro from Cleveland Clinic in USA performed the first CABG it has become one of the most popular surgicalprocedure in the world

30. CABG or OPCAB? • The biggest advantage of OPCAB is avoidance of complications related to CPB e.g. SIRS and slightlylower costs • However, OPCAB provides less completeness of revascularization and worse precision of anastomosis (moving operating area) • Classic indication for OPCAB is isolated stenosis of LAD not suitable for PCI e.g. amputation

31. OPCAB

32. Cardio-Pulmonary Bypass (CPB)

33. Cardio-Pulmonary By-Pass (CPB)Extracorporeal circulation (ECC) • Requires full heparinization of the patient • Main elements: • System of cannules, tubes and filters • Oxygenator • Pumps (arterial and suction) • Side effects • Blood cells damage • Systemic InflammatoryResponse Syndrome (SIRS)

34. Indications for CABG • Left main stem stenosis > 50% • Equivalent of LMS stenosis (proximal stenosis of LAD and Cx > 75%) • Three-vessels disease (stenoses of RCA, LAD and Cx or their branches >75%) • Proximal LAD stenosis >75% with one- or two-vessels disease, with excessive part of myocardium in jeopardy, especially in patients with poor LV function and/or in diabetics (not suitable for PCI, method of choice if isolated– OPCAB)

35. Counter-indications for CABG • Acute myocardial infarction (2 weeks) • Use of antiplatelet drugs like ticlopidine or clopidogrel (2 weeks or platelet concentrate – if emergency) • Lack of graftable distal vessels (diameter of at least 1,5mm) – consider TMLR

36. Scheduled or emergency CABG?

37. Patient’s Preparation to Scheduled CABG • Red cells concentrate (autotransfusion, family donations) • Coagulometry • Cessation of antiplatelet drugs (2 weeks before surgery) • Optimal medical treatment (beta-blockers, statins, control of glycemia in diabetics) • Co-morbidities (carotid doppler, gastroscopy)

38. Predictors of Outcomes after CABG • Age > 60 years • Female sex • Poor LV function • Re-do operation • Emergency • Obesity • Co-morbidities • Renal failure • Chronic Obturatory Pulmonary Disease • Stroke • Generalized atherosclerosis

39. CABG-Technique • Medial Sternotomy • Use of CPB • Saphenous by-pass grafts (SBG) or arterial grafts

40. Material for Grafts in CABG • Saphenous vein (SBG) • Left internal thoracic artery (LITA) • Right internal thoracic artery (RITA) • Radial artery (RA) • Gastroepiploic artery

41. Venous or arterial grafts? • Arterial grafts are generally better than venous – e.g. LITA patency rate after 20 years is 90% whereas 50% of SBGs is occluded after 10 years.GOLDEN STANDARD: LITA to LAD! • Totally arterial revascularization is especially indicated in young patients and in those with bilateral crural varicosity

42. CABG

43. Venous grafts

44. Venous sequential graft

45. Harvested LITA

46. Graft: LITA to LAD

47. Harvesting and anastomosing of Radial Artery

48. Outcomes of CABG • Mortality rate 1-5% - depends mostly of patients’ profile (see predictors of outcomes ) • Common postop. complications: • Excessive bleeding, heart tamponade • Perioperative myocardial infarction - low cardiac output • Stroke or psycho-organic syndromes • Acute renal failure • Hemothorax, pneumothorax • Sternal dehiscence, mediastinitis

49. Typical uncomplicated course after CABG • ICU 1-2 days: • Artificial ventilation <12 hours • Chest tubes – 2 days • Hospital stay – about 1 week • Antibiotics – 4 days • Rehabilitation 2-3 weeks • Most of the patients returns to normal activity in few months

50. Standard Medication after CABG„A B S” • ASA 150-300 mg daily • Beta-Blockers • Statins