Coronary Artery Bypass Grafting (CABG) Procedure and Outcomes

Standard Surgical Approach

The American College of Cardiology recommends that the left internal mammary artery (LIMA) should be the primary conduit for revascularization of the LAD artery in all patients, as this is associated with improved long-term outcomes 1, 2
Most CABG procedures are performed using extracorporeal circulation (cardiopulmonary bypass or CPB) in approximately 70% of operations worldwide, with a median sternotomy providing full access to the heart and great vessels 3, 4

Most coronary bypass grafts are constructed with hand-sewn suture techniques for both proximal and distal anastomoses, using continuous polypropylene suture or interrupted silk sutures with similar outcomes 4, 5
Proximal anastomoses are typically created on the ascending aorta, while distal anastomoses are created on the target coronary arteries beyond the stenosis, with aortic cross-clamping and various methods of myocardial protection employed during this period 4, 3

The American Heart Association recommends transesophageal echocardiography (TEE) for evaluation of acute, persistent, and life-threatening hemodynamic disturbances, patients undergoing concomitant valvular surgery, and monitoring hemodynamic status, ventricular function, regional wall motion, and valvular function during CABG 4, 5

The American College of Cardiology recommends that clopidogrel should be withheld for 5 days before CABG surgery to reduce bleeding risk, and beta-blockers should not be discontinued before surgery to avoid acute ischemia 1, 2, 3

Early clinical outcomes at 3 months after CABG include a 1-2% mortality rate and a 1-2% morbidity rate for each of: stroke, renal failure, pulmonary failure, cardiac failure, bleeding, and wound infection, with hospital mortality higher for urgent procedures and patients with left main stenosis or diabetes 3
The European Society of Cardiology reports that patients with diabetes have higher mortality (2.6%) compared to those without (1.6%) 3

The American Heart Association recommends that in patients with recent myocardial infarction, CABG mortality is elevated for the first 3-7 days after infarction, and the benefit must be balanced against this increased risk, and techniques that minimize aortic manipulation may reduce neurological complications in patients with diseased ascending aortas 6, 7, 4

The American College of Cardiology recommends that clopidogrel and ticagrelor should be discontinued at least 5 days before elective surgery, and prasugrel should be discontinued at least 7 days before surgery, with aspirin (100-325 mg daily) administered preoperatively in patients undergoing coronary artery bypass grafting 8

The European Heart Journal recommends the use of radial artery from the non-dominant arm as an additional conduit, and the pericardium should be opened to expose the heart, with systemic heparinization administered and cardiopulmonary bypass initiated after achieving adequate anticoagulation in patients undergoing coronary artery bypass grafting 9
The European Heart Journal also recommends off-pump coronary artery bypass (OPCAB) as an alternative technique, which may be performed without cardiopulmonary bypass using stabilizing devices to immobilize the target area of the beating heart 9

The American College of Cardiology recommends minimally invasive direct coronary artery bypass (MIDCAB) as an alternative technique, which uses smaller incisions for selected cases, and hybrid coronary revascularization, which combines LIMA-to-LAD grafting with percutaneous coronary intervention (PCI) of non-LAD vessels, may be reasonable in patients with heavily calcified proximal aorta or poor target vessels for CABG 8

The American Heart Association recommends using additional arterial grafts for remaining significant stenoses (>70% diameter narrowing or >50% for left main) 10
Elderly or high-risk patients may receive more saphenous vein grafts due to shorter life expectancy making long-term graft patency less critical 11

Target vessel quality requires distal vessels to be >1.5mm diameter with adequate runoff for successful grafting 10
The American College of Cardiology indicates that bypass grafting is indicated for ≥70% diameter stenosis in major vessels or ≥50% in left main coronary artery 10

Emergency or urgent coronary artery bypass grafting—such as procedures performed after failed percutaneous coronary intervention or in patients with cardiogenic shock—requires additional operative time because hemodynamic stabilization must be achieved before and during surgery. 12, 13

Emergency and urgent CABG cases are associated with a higher risk of adverse outcomes compared with elective procedures, reflecting the increased physiological stress and complexity of these situations. 12, 13