Sex Difference in Coronary Artery Bypass Grafting: Preoperative Profile and Early Outcome

Area of Science:

• Cardiovascular Surgery
• Medical Statistics
• Health Outcomes Research

Background:

• Existing risk-stratification systems indicate higher mortality rates for women post-coronary artery bypass grafting (CABG) compared to men.
• Investigating the underlying factors contributing to this observed sex-based disparity in outcomes is crucial for improving patient care.

Purpose of the Study:

• To analyze the CABG database and identify specific factors responsible for the differential mortality risk between men and women undergoing the procedure.
• To understand how known risk factors for early mortality differ in their predictive value between sexes.

Main Methods:

• A retrospective analysis of a single-center CABG database involving 17,919 patients (4,016 women, 13,903 men) between January 1998 and July 2016.
• Comparison of baseline characteristics, procedural data (graft number, cross-clamp time), and early mortality rates between male and female patients.
• Logistic regression analysis to identify independent risk factors for early mortality in each sex.

Main Results:

• Women exhibited significantly higher early mortality (2.7% vs. 1.9%, p=0.001) and presented with distinct baseline profiles, including older age, lower hemoglobin, and varied BMI distribution (underweight and obesity).
• Women received fewer grafts on average, and their mean cross-clamp time per graft was longer.
• Logistic regression revealed that chronic obstructive pulmonary disease, peripheral vascular disease, cross-clamp time, and underweight were independent risk factors for early mortality exclusively in men.

Conclusions:

• Significant preoperative differences exist between men and women undergoing CABG, impacting their risk profiles.
• The predictive significance of established risk factors for early mortality varies considerably between sexes, necessitating tailored risk assessment strategies.