Increased risk of cardiovascular mortality by strict glycemic control (pre-procedural HbA1c 6.5%) in Japanese medically-treated diabetic patients following percutaneous coronary intervention: a 10-year follow-up study

Background In the secondary prevention of cardiovascular (CV) disease in patients with diabetes, an optimal level of HbA1c, the most widely-used glycemic control indicator, for favorable clinical consequences still remains to be established. This study assessed the association between preprocedural HbA1c level and CV mortality in Japanese diabetic patients undergoing percutaneous coronary intervention (PCI). Methods This is a retrospective observational study using a single-center prospective PCI database involving consecutive 4542 patients who underwent PCI between 2000 and 2016. Patients with any antidiabetic medication including insulin at PCI were included in the analysis (n = 1328). We divided the patients into 5 and 2 groups according to HbA1c level; HbA1c: and ≤ 7.0%, respectively. The primary outcome was CV mortality including sudden death. The median follow-up duration was 6.2 years. Results In the follow-up period, CV and sudden death occurred in 81 and 23 patients, respectively. While unadjusted Kaplan–Meier analysis showed no difference in cumulative CV mortality rate between patients binarized by preprocedural HbA1c 7.0%, analysis of the 5 groups of HbA1c showed significantly higher cumulative CV death in patients with HbA1c Conclusion The findings indicate an increased risk of CV mortality by strict glycemic control (HbA1c Trial registration This study reports the retrospective analysis of a prospective registry database of patients who underwent PCI at Juntendo University Hospital, Tokyo, Japan (Juntendo Physicians’ Alliance for Clinical Trials, J-PACT), which is publicly registered (University Medical Information Network Japan-Clinical Trials Registry UMIN-CTR 000035587).