Emergency conversion in off-pump coronary artery bypass grafting

Area of Science:

• Cardiovascular Surgery
• Thoracic Surgery
• Cardiac Anesthesia

Background:

• Emergency conversion to cardiopulmonary bypass during off-pump coronary artery bypass grafting (OPCAB) is associated with adverse outcomes.
• Understanding risk factors for conversion is crucial for patient safety and surgical planning.

Purpose of the Study:

• To evaluate the impact of emergency conversion to cardiopulmonary bypass on operative mortality and morbidity in OPCAB.
• To identify predictors of emergency conversion and specific complications.

Main Methods:

• Retrospective review of 616 consecutive patients undergoing planned OPCAB from April 2001 to July 2004.
• Comparison of outcomes between patients requiring emergency conversion (n=14) and those not converted (n=602).
• Multivariable analysis to identify predictors of conversion and associated risk factors.

Main Results:

• Emergency conversion occurred in 2.3% of patients, with a significantly higher operative mortality (13.3% vs. 1.2%, P<0.001).
• Conversion was associated with increased rates of reoperation for bleeding (7.1% vs. 1.0%, P=0.032) and respiratory failure (35.7% vs. 3.3%, P<0.001).
• Mitral regurgitation and chronic obstructive pulmonary disease predicted conversion; mitral regurgitation and lack of a heart positioning device predicted hemodynamic compromise.

Conclusions:

• Emergency conversion during OPCAB substantially increases operative mortality and morbidity.
• Mitral regurgitation and chronic obstructive pulmonary disease are significant risk factors for emergency conversion.
• Utilizing a heart positioning device may mitigate hemodynamic compromise during circumflex artery anastomosis.