Impact of transient decrease in mixed venous oxygen saturation on prognosis in off-pump coronary artery bypass...

Area of Science:

• Cardiovascular Surgery
• Hemodynamics
• Surgical Outcomes

Background:

• Prognostic implications of transient hemodynamic changes during off-pump coronary artery bypass surgery (OPCAB), particularly during left circumflex artery (LCX) grafting, remain unclear.
• Cardiac displacement during OPCAB can lead to hemodynamic deterioration, impacting patient outcomes.

Purpose of the Study:

• To investigate the association between low mixed venous oxygen saturation (SvO2) < 60% during LCX grafting and the occurrence of composite morbidity endpoints in OPCAB patients.
• To identify risk factors for adverse outcomes following elective OPCAB.

Main Methods:

• Retrospective review of 1,071 patients undergoing elective OPCAB between January 2010 and December 2019.
• Logistic regression analysis to identify risk factors for a composite of morbidity endpoints (30-day/in-hospital mortality, myocardial infarction, prolonged mechanical ventilation, stroke, acute kidney injury).

Main Results:

• A composite of morbidity endpoints occurred in 28% of patients.
• SvO2 < 60% during LCX grafting was significantly associated with increased morbidity (OR: 2.72).
• Pre-operative anemia predicted lower SvO2 during LCX grafting (OR: 2.09).

Conclusions:

• A transient decrease in SvO2 < 60% during LCX grafting is linked to a 2.7-fold increased risk of adverse outcomes in OPCAB.
• This finding highlights the prognostic importance of transient oxygen supply-demand imbalance during cardiac displacement in OPCAB.