HbA1c and renal failure
A recent prospective study reported that acute renal failure is one of the most common complications in the post-CABG in diabetic patients50. Compared with diabetic patients with HbA1c ≤ 7%, those with HbA1c > 7% had more incidence of renal failure (10% vs. 0%) 47. Additionally, the results of recent meta-analysis, involving nine studies (n = 5,858), suggested that a higher preoperative HbA1c level was associated with a high risk of renal failure after cardiac surgery (OR = 1.63, 95% CI 1.13-2.33, p  = 0.47, and I 2 = 0%)48. Furthermore, by using receiver operating characteristic value thresholds, Halkos et al. showed that renal failure occurred more commonly in patients with elevated HbA1c (threshold 6.7, odds ratio 2.1) 20. It is worth noting that the 6.7 threshold derived is the below the 7% glycaemic target of the American Diabetes Association 15.