Survival after coronary artery bypass grafting. Experience from 4661 patients

Area of Science:

• Cardiovascular Surgery
• Outcomes Research
• Epidemiology

Background:

• Assessing long-term mortality after coronary artery bypass grafting (CABG) is crucial for patient management.
• Excess mortality in CABG patients compared to the general population requires detailed temporal analysis.

Purpose of the Study:

• To evaluate the duration of reduced mortality following CABG.
• To analyze excess mortality trends in CABG patients over time relative to the general population.

Main Methods:

• Survival analysis of 4661 patients undergoing first isolated CABG.
• Calculation of relative survival using Swedish population data stratified by age, sex, and calendar period.
• Multivariate modeling adjusted for age, surgery year, disease severity, left ventricular function, and smoking.

Main Results:

• Relative survival rates were 94.6% at 5 years, 82.5% at 10 years, and 59.9% at 15 years.
• Excess mortality risk (relative hazard) peaked around 8 years post-surgery, significantly increasing thereafter.
• Smoking and pre-operative moderate/severe left ventricular dysfunction worsened relative survival.
• Patients operated on after 1985 demonstrated higher survival rates.

Conclusions:

• The mortality benefit of CABG diminishes significantly beyond 8 years post-operation.
• Pre-operative factors like smoking and left ventricular function impact long-term survival.
• Improvements in surgical timing and patient selection (post-1985) are associated with better long-term outcomes.