People with diabetes continue to be a high-risk cohort for coronary artery bypass graft (CABG) surgery, with rates of postoperative adverse outcomes two to three times greater than people without diabetes, according to WA researchers.

A retrospective analysis of 1327 patients who underwent CABG surgery at the Fiona Stanley  hospital after it opened in 2015 found that the 572 (43%) of patients with diabetes had double the rate of post-operative wound infections (3.1% vs. 1.5%, p<0.022), than those without diabetes.

People with diabetes also had higher rates of 30-day hospital admission (13.1% vs. 8.5%, p < 0.007) than people without diabetes following CABG surgery.

Rates of post-operative acute kidney injury as measured by new dialysis requirement were three times higher in people with diabetes than people without diabetes (2.9% vs. 1.0%, p< 0.009)

However, there were no significant differences in early rates of postoperative myocardial infarction, stroke and 30-day all-cause mortality, which were low in both people with and without diabetes.

The review showed that people with diabetes undergoing CABG had higher rates of co-morbidities and metabolic risk factors such as dyslipidaemia (83% vs 68%,), hypertension (82% vs 69%), raised BMI (29.8 vs 28.7kg/m2), prior myocardial infarction (63% vs 55%), prior stroke (9% vs 5%), congestive cardiac failure (20% vs 15%), reduced estimated glomerular filtration rate (87 vs 91 ml/min/1.73 m2) and three-vessel coronary artery disease (75% vs 67%).

The researchers noted that in contrast to some previous studies, the adverse short-term post-operative outcomes did not differ significantly between people with insulin and non-insulin treated diabetes, despite a higher prevalence of peripheral vascular disease and congestive cardiac failure in those with insulin-treated diabetes.

They said this might be because patients with insulin-treated diabetes are often viewed by clinicians as being at higher risk of complications following CABG surgery and therefore referred earlier and receive closer multi-disciplinary management.

Nevertheless, the study showed that a high proportion of CABG surgery patients have diabetes and have a high risk of complications and extended hospital stays, they said.

“This has clinical implications with regards to healthcare resource allocation, healthcare costs, patient informed consent and the need for additional strategies to reduce [postoperative] adverse events,” they concluded.

The findings are published in Diabetes & Metabolic Syndrome: Clinical Research & Reviews.