Coronary Artery Bypass Grafting - Risks & Benefits

Risks and benefits of Coronary Artery Bypass Grafting (CABG)

If you have heart disease and want help deciding what treatment is best for you, check this out (you will need to have information about your coronary arteries and heart condition):

As a rule, these days patients are only referred by their cardiologists for CABG if a PCI has failed or is technically too difficult to perform. CABG patients are older, sicker, and have complicating factors such as poor heart function and Diabetes. They have multi-vessel disease and/or Left Main Stenosis, and often coronary arteries too small for PCI. In addition, CABG is used as a bail-out procedure for catastrophic Percutaneous Coronary Intervention (PCI) failures.  All these factors influence outcomes such as survival and postoperative complications. A patient who is relatively young with a good heart runs an operative risk of dying of less than 1-2% in the hands of an experienced cardiac surgeon. The statistics below indicate how many patients in a surgical practice are not in this category:

  • Overall mortality related to CABG: 3-4%.
  • About 5% of patients require exploration because of bleeding. This second surgery increases the risk of chest infection and lung complications.
  • Stroke occurs in 1-2%, primarily in elderly patients.
  • Mortality and complications increase with:
    • age (older than 70 years),
    • poor heart muscle function,
    • disease obstructing the left main coronary artery,
    • diabetes,
    • chronic lung disease, and
    • chronic kidney failure.
  • Mortality may be higher in women, primarily due to their advanced age at the time of CABG surgery and smaller coronary arteries.

Women develop coronary artery disease about 10 years later than men because of hormonal "protection" while they still regularly menstruate (although in women with risk factors for coronary artery disease, especially smoking, elevated lipids, and diabetes, the possibility for the development of coronary artery disease at a young age is very real).

Women are generally of smaller stature than men, with smaller coronary arteries. These small arteries make CABG surgery technically more difficult and prolonged. The smaller vessels also decrease both short and long-term graft function.

What are the long-term results after CABG surgery?

Recent data has shown that in CABG patients with elevated LDL cholesterol (bad cholesterol) levels, use of cholesterol-lowering medications (particularly the statin family of drugs) to lower LDL levels to below 80 will significantly improve long-term graft patency as well as improve survival benefit and heart attack risk. Patients are also advised about the importance of lifestyle changes to lower their chance of developing further atherosclerosis in their coronary arteries. These include stopping smoking, exercise, reducing weight and dietary fat, as well as controlling blood pressure and diabetes.

Frequent monitoring of CABG patients with physiologic testing can identify early problems in grafts. PCI, in addition to aggressive risk factor modification, may significantly limit the need for repeat CABG years later.

Repeat CABG surgery is occasionally necessary, but may have a higher risk of complication.

How do CABG surgery and angioplasty (PTCA) compare?

Ongoing studies are comparing the treatment results of angioplasty (PTCA) versus bypass (CABG surgery) in patients who are candidates for either procedure. Both procedures are very effective in reducing angina symptoms, preventing heart attacks, and reducing death.

Studies have shown an advantage to CABG in patients with multi-vessel disease, Left Main Stenosis, impaired heart function and  Diabetes.

References: American Heart Association, "Open-Heart Surgery Statistics" Last Editorial Review: 5/7/2007