Coronary Artery Bypass Graft (CABG): Indications
Author: Breanne Gordulic Reviewers: Miranda Schmidt Ben Campbell Sunawer Aujla Angela Kealey* * MD at time of publication
Symptomatic multivessel (≥ 3 vessels) coronary artery disease (MVCAD) or complex MVCAD
Acute coronary syndrome (ACS)
Left main coronary artery disease
Multivessel (≥ 3 vessels) CAD and diabetes
Cardiac surgery required for other pathology
Multivessel CAD, LV dysfunction and congestive heart failure (CHF)
Complex CAD includes stenosed vein grafts, bifurcation lesions, calcified lesions, total occlusions, ostial lesions
STEMI initial treatment is PCI/thrombolysis
CABG outcomes compared to percutaneous coronary intervention (PCI) in MVCAD include ↑ survival in diabetes, ↑ survival with LV dysfunction, ↓ repeat revascularization, ↓ myocardial infarction, ↓ stroke
↑ Risk of failure in complex CAD with PCI
Rapid reperfusion to myocardium most important in STEMI to decrease myocardial damage
CABG can be considered for residual stenoses 6-8 weeks later
NSTEMI or unstable angina (UA) with MVCAD involving at least three vessels including the proximal left anterior descending (LAD)
Left main coronary artery divides into left anterior descending (LAD) and left circumflex (LCx) which supplies 2/3 of myocardium
↑ Survival Myocardial infarction from left main artery occlusion Death
Left main stenosis
Ventricular dysrhythmias
Ongoing ischemia
LV dysfunction Hemodynamic instability
↑ risk of PCI
CABG has mortality benefit
↓ Number of operations
↑ Risk of cardiovascular disease in diabetes
Revascularization indicated along with other cardiac surgery
Multivessel CAD with >90% stenosis and CHF
LV ejection fraction <35% ↑ Risk of atherosclerosis from hyperglycemia and dyslipidemia CABG bypasses several atherosclerotic plaques in coronary arteries ↑ Durability ↑ Complete perfusion Valve stenosis or regurgitation Septal defect Aortic root or arch pathology Combination procedure Evidence of ischemia at rest Evidence of impaired LV function at rest ↓ All-cause mortality in CABG vs medical management Chronic obstructive pulmonary disease Abbreviations: • ACS- acute coronary syndrome. Acute reduction in blood flow to heart muscle resulting in cell death. • CAD- coronary artery disease. Narrowing or blockage of the coronary arteries by plaque • NSTEMI- myocardial infarction (heart attack) with no ST elevation on electrocardiogram • PCI- percutaneous coronary intervention. A balloon tipped catheter is used to open blocked coronary arteries; a stent may be placed. • STEMI- myocardial infarction with ST segment elevation on electrocardiogram Consider revascularization (restore blood flow to blocked or narrowed blood vessels) of coronary arteries to increase perfusion to myocardium (heart muscle) Coronary artery bypass graft recommended Assess surgical risk and comorbidities with evaluation by heart team that includes both a cardiac surgeon and interventional cardiologist (SYNTAX Trial) Individual management plan for patients with comorbidities that increase mortality Frailty Chronic Renal Failure ↑ Inflammation and deregulated angiogenesis affects all organ systems ↓ Physiologic reserve and ↓ ability to recover from acute stress ↑ Pneumonia ↑ Respiratory and Renal Failure ↑ Stroke ↑ In hospital mortality ↓ Survival two years after surgery Use Society of Thoracic Surgeons Score, EuroSCORE, or SYNTAX II Score to predict patient outcome with anatomy, disease severity, and preoperative characteristics Coronary Artery Bypass Graft Surgery to take healthy blood vessels from the body and connect them proximally and distally to blocked coronary arteries Cardiopulmonary bypass, fluid overload, ↑ renal vasoconstriction and ↓ renal oxygenation from rewarming Kidney injury ↑ End stage kidney disease Blood flow restored to ischemic myocardium ↓ Angina ↑ Quality of life ↑ LV function ↑ Survival Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published April 12, 2023 on www.thecalgaryguide.com