Coronary Artery Bypass Surgery - Indications For CABG

Indications For CABG

Several alternative treatments for coronary artery disease exist. They include:

• Medical management (anti-anginal medications plus statins, antihypertensives, smoking cessation, tight blood sugar control in diabetics)
• Percutaneous coronary intervention (PCI)

Both PCI and CABG are more effective than medical management at relieving symptoms, (e.g. angina, dyspnea, fatigue). CABG is superior to PCI for some patients with multivessel CAD

The Surgery or Stent (SoS) trial was a randomized controlled trial that compared CABG to PCI with bare-metal stents. The SoS trial demonstrated CABG is superior to PCI in multivessel coronary disease.

The SYNTAX trial was a randomized controlled trial of 1800 patients with multivessel coronary disease, comparing CABG versus PCI using drug-eluting stents (DES). The study found that rates of major adverse cardiac or cerebrovascular events at 12 months were significantly higher in the DES group (17.8% versus 12.4% for CABG; P=0.002). This was primarily driven by higher need for repeat revascularization procedures in the PCI group with no difference in repeat infarctions or survival. Higher rates of strokes were seen in the CABG group.

The FREEDOM (Future Revascularization Evaluation in Patients With Diabetes Mellitus—Optimal Management of Multivessel Disease) trial will compare CABG and DES in patients with diabetes. The registries of the nonrandomized patients screened for these trials may provide as much robust data regarding revascularization outcomes as the randomized analysis.

A study comparing the outcomes of all patients in New York state treated with CABG or percutaneous coronary intervention (PCI) demonstrated CABG was superior to PCI with DES in multivessel (more than one diseased artery) coronary artery disease (CAD). Patients treated with CABG had lower rates of death and of death or myocardial infarction than treatment with a coronary stent. Patients undergoing CABG also had lower rates of repeat revascularization. The New York State registry included all patients undergoing revascularization for coronary artery disease, but was not a randomized trial, and so may have reflected other factors besides the method of coronary revascularization.

The 2004 ACC/AHA CABG guidelines state CABG is the preferred treatment for:

• Disease of the left main coronary artery (LMCA).
• Disease of all three coronary vessels (LAD, LCX and RCA).
• Diffuse disease not amenable to treatment with a PCI.

The 2005 ACC/AHA guidelines further state: CABG is the preferred treatment with other high-risk patients such as those with severe ventricular dysfunction (i.e. low ejection fraction), or diabetes mellitus.