What is the peri-operative mortality rate for Coronary Artery Bypass Grafting (CABG) during the surgery itself, in other words, what percentage of patients survive the surgery?

From the Guidelines

The perioperative mortality rate for coronary artery bypass graft (CABG) surgery is generally low, with approximately 96-99% of patients surviving the procedure itself, as indicated by the overall operative mortality for CABG being between 1–4% 1. This means that about 1-4% of patients may not survive the immediate surgical period. The mortality risk varies significantly based on patient factors including age, presence of comorbidities (especially diabetes, kidney disease, or previous heart attacks), urgency of the procedure (elective vs. emergency), and the patient's overall cardiac function. Some key points to consider include:

• Hospital and surgeon experience also play important roles in outcomes.
• The primary causes of perioperative mortality include myocardial infarction, heart failure, bleeding complications, stroke, and severe arrhythmias.
• Modern surgical techniques, improved anesthesia protocols, better myocardial protection strategies, and enhanced postoperative care have contributed to the relatively low mortality rates seen today compared to historical figures, as seen in studies such as 1. Patients should understand that while the immediate surgical risk is relatively low, the overall 30-day mortality (which includes complications that may arise after the procedure) is a more comprehensive measure of surgical risk and may be slightly higher than the intraoperative mortality rate alone. Some of the factors that can influence the perioperative mortality rate include:
• The use of extra-corporeal circulation (cardiopulmonary bypass) to perform coronary artery surgery remains the most commonly used approach, but so-called ‘off-pump’ surgery may lead to a reduction in perioperative mortality and morbidity 1.
• The type of graft used, with the left internal thoracic artery (LITA) graft improving survival and reducing the incidence of late myocardial infarction, recurrent angina, and the need for further cardiac interventions 1.

From the Research

Peri-operative Mortality Rate for CABG

• The peri-operative mortality rate for CABG is a critical measure of the safety of the procedure.
• According to a study published in 1994 2, the overall peri-operative mortality rate did not differ significantly between patients younger than 75 years (2.9%) and patients aged 75 years or older (2.7%).
• A study published in 2011 3 identified risk factors for operative mortality in 1,098 patients with coronary artery bypass grafting surgery, including age, acute coronary syndrome, emergent surgery, chronic renal failure, and concomitant peripheral vascular disease.
• Another study published in 2017 4 found that the 30-day adjusted mortality rate ratio for isolated CABG surgery was 13.51 (95% confidence interval [CI], 12.59-14.49), indicating a higher mortality risk in patients undergoing CABG surgery compared to the general population.
• A more recent study published in 2024 5 reported that CABG was associated with an increased risk of all-cause mortality within 30 days (hazard ratio [HR], 4.81; 95% confidence interval [CI], 1.95-11.83) but a subsequent reduction in the long-term risk of death (HR, 0.79; 95% CI, 0.69-0.89).

Survival Rate After CABG

• The survival rate after CABG surgery is an important consideration for patients and healthcare providers.
• A study published in 1994 2 found that the 3-year survival rate was 93% and the 3-year cardiac event-free rate was 88% for patients aged 75 years or older who underwent CABG surgery.
• Another study published in 2017 4 reported that the cumulative 10-year mortality rate was lower in patients treated with CABG compared to medical therapy (45.1% vs 51.7%, respectively; odds ratio, 0.70; 95% CI, 0.58-0.85).
• A study published in 2024 5 found that the survival advantage for CABG became significant after the fourth postoperative year and was particularly pronounced in younger and non-White patients.

Factors Influencing Peri-operative Mortality

• Several factors can influence peri-operative mortality after CABG surgery, including age, emergent surgery, chronic renal failure, and concomitant peripheral vascular disease 3.
• The use of beta-blocker therapy has been shown to reduce mortality and improve outcomes in patients undergoing CABG surgery, particularly those with a history of previous myocardial infarction or congestive heart failure 6.