CABG (pronounced “cabbage”) stands for coronary artery bypass grafting, an open-heart surgery that reroutes blood around blocked or narrowed arteries to restore normal blood flow to the heart muscle. It is one of the most commonly performed heart surgeries in the world and remains the preferred treatment for patients with multiple blocked coronary arteries, particularly those with diabetes or reduced heart function.
Why CABG Is Performed
Coronary arteries supply oxygen-rich blood to the heart. When fatty deposits build up inside these arteries (a process called atherosclerosis), the heart muscle doesn’t get enough blood, causing chest pain, shortness of breath, or heart attacks. CABG creates a detour around those blockages using blood vessels harvested from elsewhere in the body.
Not everyone with blocked arteries needs surgery. CABG is typically recommended when blockages are too severe or widespread for stents (small mesh tubes inserted through a catheter) to handle effectively. The strongest recommendations apply to patients with left main coronary artery disease (more than 50% narrowed), triple-vessel disease (three major arteries blocked), or two-vessel disease involving the artery that runs down the front of the heart. Patients with diabetes or weakened heart pumping function also tend to do significantly better with bypass surgery than with stents. In a large analysis of over 60,000 patients from the New York Cardiac Registry, CABG was associated with higher long-term survival than stenting for patients with two or more diseased arteries.
A scoring system called the SYNTAX score helps cardiologists assess how complex a patient’s blockages are. Patients with high scores, meaning more complex anatomy, tend to have worse outcomes with stents and are encouraged to undergo CABG instead.
How the Surgery Works
The operation begins with general anesthesia and a vertical incision down the center of the chest. The surgeon divides the breastbone (sternum) to access the heart. While the surgical team prepares the chest, an assistant simultaneously harvests blood vessels from the leg, arm, or chest wall to use as bypass grafts.
In the traditional approach (on-pump CABG), the heart is temporarily stopped using a solution that pauses its beating. A heart-lung machine takes over, pumping oxygenated blood through the body while the surgeon works on a still, bloodless field. The surgeon sews one end of each graft to the coronary artery below the blockage and the other end to the aorta, creating a new path for blood to reach the heart muscle. Once the grafts are in place, the heart is restarted, blood flow through the grafts is checked, and the breastbone is closed with steel wires.
There is also an off-pump variation, where the surgeon operates on a beating heart using a stabilizing device to hold the target area still. Off-pump surgery avoids the heart-lung machine entirely, which lowers complication rates (roughly 10.6% versus 14.2% with on-pump) and operative mortality (2.3% versus 2.9%). However, on-pump surgery achieves more complete revascularization (88% versus 79%), making it the better choice when a patient needs more than three grafts or in emergency situations. Off-pump surgery tends to benefit elderly and high-risk patients most.
Where the Bypass Grafts Come From
The gold standard graft is the left internal mammary artery, a vessel that runs along the inside of the chest wall. Surgeons almost always use it to bypass the left anterior descending artery, the most important coronary artery. This graft has a 10-year patency rate of 90% to 95%, meaning it stays open and functional in the vast majority of patients for over a decade.
For additional bypasses, surgeons choose between veins from the leg (the great saphenous vein) and arteries from the forearm (the radial artery). Saphenous vein grafts are the most commonly used, but they have a significant drawback: they tend to fail over time, with only a small number staying open beyond 10 years. In one trial, 13.6% of vein grafts were completely blocked at one year compared to 8.2% of radial artery grafts. At five years, the gap widened further, with radial artery grafts showing 98.3% patency versus 86.4% for veins.
For patients over 70, the difference in graft choice has a measurable impact on survival. A study of over 2,100 patients found that those who received an internal mammary artery plus a radial artery graft had 10-year survival of 70.9%, compared to just 50.5% for those who received an internal mammary artery plus a saphenous vein graft. Removing the radial artery from the forearm does not affect blood supply to the hand, since the other artery in the arm compensates.
CABG Versus Stents for Diabetic Patients
The advantage of CABG over stenting is most dramatic in patients with diabetes and multiple blocked arteries. In a six-year follow-up study, the rate of major adverse events (heart attacks, strokes, death, or the need for another procedure) was 44.9% in the CABG group compared to 83.6% in the stent group. The need for a repeat procedure was especially striking: 17.3% after CABG versus 47.0% after stenting. This is consistent with findings from the landmark BARI trial, which showed significantly higher five-year survival for insulin-requiring diabetic patients who underwent CABG rather than stenting.
Risks and Complications
CABG is major surgery, and about 14% of patients experience some complication within 30 days. Most of these are manageable, but some are serious.
- Stroke occurs in 1.4% to 3.8% of patients after surgery. The risk increases if the patient develops an irregular heart rhythm (atrial fibrillation) afterward, which roughly doubles the chance of a stroke-related event.
- Wound infection at the chest incision is relatively common in its superficial form (0.5% to 8% of cases) but rarely progresses to a deep infection involving the breastbone (1% to 2%). Deep infections, though rare, carry mortality rates up to 30% and require aggressive treatment.
- Cognitive changes such as memory difficulties or trouble concentrating affect some patients in the weeks after surgery. These issues typically improve over time.
Recovery Timeline
You will spend about one week in the hospital after CABG. The first day or two are in the intensive care unit, where the medical team monitors your heart rhythm, blood pressure, and breathing while you wake from anesthesia. After moving to a regular hospital room, you’ll begin sitting up, walking short distances, and gradually eating solid food.
Once you’re home, full recovery takes 6 to 12 weeks. Common side effects during this period include fatigue, chest soreness, mild swelling at incision sites, and mood changes. These typically resolve within 4 to 6 weeks. You’ll have lifting restrictions (usually nothing over 10 pounds) while your breastbone heals, and driving is off-limits for several weeks.
Cardiac Rehabilitation After Surgery
Cardiac rehab is a structured program that most patients begin within a few weeks of surgery. It combines supervised exercise, nutritional counseling, weight management, and psychological support. The exercise goal is at least 150 minutes per week of moderate-intensity activity (like brisk walking) or 75 minutes of vigorous activity, built up gradually under professional guidance. Sessions also include strength training and coaching on how to stay active safely long-term.
Dietary counseling focuses on heart-protective eating patterns. Programs typically recommend Mediterranean, low-carbohydrate, high-protein, or plant-based diets depending on the patient’s needs, with particular attention to managing blood sugar in patients with diabetes. Rehab also addresses the emotional side of recovery, since anxiety and depression are common after open-heart surgery and can slow progress if left unaddressed.
Long-Term Outlook
The durability of CABG depends heavily on which grafts are used. At 10 to 16 years after surgery, the internal mammary artery graft remains open in about 90% of patients. Radial artery grafts hold up reasonably well at around 79%, while saphenous vein grafts show patency of roughly 74% over the same period. Patients who receive arterial grafts rather than vein grafts consistently show better long-term survival.
CABG does not cure coronary artery disease. The underlying process that caused the original blockages continues, and grafts themselves can develop narrowing over time. Staying on prescribed medications, maintaining a heart-healthy diet, exercising regularly, and not smoking are all critical for keeping grafts open and preventing new blockages from forming.