Elevated glycosylated haemoglobin (HbA1c) is a risk marker in   coronary artery bypass surgery.
OBJECTIVE
To evaluate if glycosylated haemoglobin 1 (HbA1c) was associated with increased risk of infection and mortality after coronary artery bypass grafting (CABG).


METHODS
Prospective observational study. Preoperative HbA1c concentrations were correlated to outcome in patients followed for an average of 3.5 years after CABG.


RESULTS
HbA1c was > or =6% in 68% of 161 patients with diabetes mellitus (DM) and in 3% of 444 patients without DM. Superficial sternal wound infection was observed in 13.9% if HbA1c > or =6% versus in 5.5% if <6% (p=0.007). Mediastinitis occurred in 4.9% if HbA1c > or =6% and in 2.1% if HbA1c <6% (p=0.20) (Hazard ratio (HR) 1.9, 95% CI 0.6-5.9). Follow-up mortality was 18.9% in patients with HbA1c > or =6% compared to 4.1% if HbA1c <6% (p<0.001) with HR 5.4, (95% CI 3.0-10.0) after multivariable adjustment. The risk of death was similar regardless of DM diagnosis.


CONCLUSIONS
HbA1c > or =6% was associated with an increased risk of postoperative superficial sternal wound infections and a trend for higher mediastinitis rate and significantly higher mortality three years after CABG.
Alserius
Thomas
T
Department of Cardiothoracic Surgery and Anaesthesiology, Karolinska University Hospital, Karolinska Institute, Stockholm, Sweden.
Anderson
Russell E
RE
Hammar
Niklas
N
Nordqvist
Tobias
T
Ivert
Torbjörn
T
D000368:Aged; D015415:Biomarkers / Q000097:blood; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000401:mortality; D003324:Coronary Artery Disease / Q000097:blood / Q000150:complications / Q000601:surgery*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008480:Mediastinitis / Q000097:blood / Q000209:etiology* / Q000401:mortality; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013249:Sternum / Q000601:surgery*; D013530:Surgical Wound Infection / Q000097:blood / Q000209:etiology* / Q000401:mortality; D013997:Time Factors; D016896:Treatment Outcome; D015854:Up-Regulation
D015415:Biomarkers; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human