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

Abstract

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: < 6.5% (n = 267), 6.5-7.0% (n = 268), 7.0-7.5% (n = 262), 7.5-8.5% (n = 287) and ≥ 8.5% (n = 244), and 7.0% > 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 < 6.5% compared with those with 7.0-7.5% (P = 0.042). Multivariate Cox hazard analysis revealed a U-shaped relationship between preprocedural HbA1c level and risk of CV death, and the lowest risk was in the HbA1c 7.0-7.5% group (Hazard ratio of HbA1c < 6.5% compared to 7.0-7.5%: 2.97, 95% confidence interval: 1.33-7.25, P = 0.007). Similarly, univariate analysis revealed the lowest risk of sudden death was in the HbA1c 7.0-7.5% group. Conclusion: The findings indicate an increased risk of CV mortality by strict glycemic control (HbA1c < 6.5%) in the secondary prevention of CV disease in Japanese patients with medically-treated diabetes.

Association of glycated hemoglobin A1c levels with cardiovascular outcomes in the general population: results from the BiomarCaRE (Biomarker for Cardiovascular Risk Assessment in Europe) consortium

“…A recent study in a smaller study population from Spain could also show the additional benefit of including HbA 1c levels for the association with CVD [ 1 ]. Extending the importance of HbA 1c levels in the clinical practice, additional data pointing out the usage of HbA 1c levels for risk stratification in patients with CVD or DM with an insufficient glucose control in patients from Asia should be noted [ 13 , 14 , 33 , 34 ].…”

J-curve relationship between long term glycemic control and mortality in diabetic patients with acute myocardial infarction undergoing percutaneous coronary intervention

“…Poor glycemic control was associated with an increased risk of mortality (HbA1c > 10%) [ 17 ] and CV events (HbA1c > 7%) [ 18 ]. A study reported that stringent glycemic control (HbA1c < 6.5%) was associated with the risk of cardiovascular death or sudden death after PCI [ 19 ]. However, the proportion of patients with AMI was 10–20% in those previous studies.…”

Screening for Glucose Metabolism Disorders, Assessment the Disse Insulin Resistance Index and Hospital Prognosis of Coronary Artery Bypass Surgery

“…Moreover, a study by Aydınlı B et al [ 18 ] found no association of high HbA1c levels with immediate CABG results. The reasons for such contradictions during long-term follow-up of patients can be numerous; one of them is shown in the study by Funamizu T, et al, where strict control of diabetes achieving the HbA1c level < 6.5 in the group of diabetes patients after PCI led to a worsening prognosis during 10-year follow-up [ 28 ]. Another possible reason is the suboptimal selection of the CMD marker.…”