Preoperative Measurement of Hemoglobin A1c for Risk Stratification
Preoperative Measurement of Hemoglobin A1c for Risk Stratification
Optimal preoperative glycemic control, defined by a hemoglobin A1c level
less than 6.5%, has been associated with significant decreases in deep sternal wound infection, ischemic events, and other complications. Evidence-based guidelines based on poor-quality meta-analyses recommend screening all patients for diabetes preoperatively and intervening to improve glycemic control to achieve a hemoglobin A1c level less than 7% in patients for whom this is relevant. Despite this recommendation, approximately 25% of patients undergoing cardiac surgery have hemoglobin A1c levels greater than 7%, and 10% have undiagnosed diabetes, indicating a failure to apply current evidence-based recommendations for preoperative diabetes management. A recent retrospective review demonstrated that preadmission glycemic control, as assessed by hemoglobin A1c, is associated with decreased long-term survival. It is unclear whether preoperative interventions in patients undergoing cardiac surgery will result in improved outcomes. Based on this moderate-quality evidence, we recommend preoperative measurement of hemoglobin A1c to assist with risk stratification (class IIa, level C-LD).
