Glycosylated hemoglobin (HbA1c) levels and clinical outcomes in diabetic patients following coronary artery stenting

BACKGROUND Diabetes has been shown to be independent predictor of restenosis after percutaneous coronary intervention (PCI). The aim of the present study was to investigate whether a pre- and post-procedural glycaemic control in diabetic patients was related to major advance cardiovascular events (MACE) during follow up. METHODS We evaluated 2884 consecutive patients including 2181 non-diabetic patients and 703 diabetics who underwent coronary stenting. Diabetes mellitus was defined as the fasting blood sugar concentration ≥ 126  mg/dL, or the use of an oral hypoglycemic agent or insulin at the time of admission. Diabetic patients were categorized into two groups based on their mean HbA1c levels for three measurements (at 0, 1, and 6  months following procedure): 291 (41.4%) diabetics with good glycaemic control (HbA1c ≤ 7%) and 412 (58.6%) diabetics with poor glycaemic control (HbA1c > 7%). RESULTS The adjusted risk of MACE in diabetic patients with poor glycaemic control (HbA1c > 7%) was 2.1 times of the risk in non-diabetics (adjusted HR = 2.1, 95% CI: 1.10 to 3.95, p = 0.02). However, the risk of MACE in diabetics with good glycaemic control (HbA1c ≤ 7%) was not significantly different from that of non-diabetics (adjusted HR = 1.33, 95% CI: 0.38 to 4.68, p = 0.66). CONCLUSIONS Our data suggest that there is an association between good glycaemic control to obtain HbA1c levels ≤7% (both pre-procedural glycaemic control and post-procedural) with a better clinical outcome after PCI.