Glycated Haemoglobin (HbA_1C) in Cardiac Surgery: A Narrative Review

Area of Science:

• Cardiology
• Endocrinology
• Anesthesiology

Background:

• Perioperative dysglycaemia in cardiac surgery is linked to adverse outcomes.
• Glycaemic variability, not just glucose levels, predicts ICU stay, creatinine rise, and acute kidney injury.
• Glycated haemoglobin (HbA1C) reflects average blood glucose and defines diabetic/pre-diabetic status, correlating with perioperative events.

Purpose of the Study:

• To review the impact of preoperative HbA1C levels on postoperative outcomes in cardiac surgery.
• To discuss the role of HbA1C in managing patients undergoing cardiac procedures.
• To synthesize current scientific understanding of HbA1C as a prognostic marker in this context.

Main Methods:

• A narrative review of studies identified through MEDLINE (PubMed) and the Cochrane Library.
• Focused search on the correlation between preoperative HbA1C levels and postoperative results.
• Analysis of existing data on HbA1C's predictive value in cardiac surgery patients.

Main Results:

• Conflicting scientific data exists regarding HbA1C's predictive power.
• Some studies indicate high HbA1C as an indicator of postoperative complications.
• Other research suggests mortality and morbidity are not solely attributable to HbA1C levels.

Conclusions:

• General agreement exists that high HbA1C levels are prognostic markers for adverse outcomes post-cardiac surgery.
• Evidence suggests multiple underlying factors contribute to these adverse outcomes.
• Further research may be needed to elucidate the complex interplay of factors.