Impact of previous insulin therapy on the prognosis of diabetic patients with acute coronary syndromes

The effects of insulin therapy on mortality in diabetic patients undergoing percutaneous coronary intervention

Background

A growing number of studies have reported insulin therapy to be associated with a higher incidence of major adverse cardiac events in diabetic patients with coronary artery disease. However, the relationship between insulin use and the clinical outcomes of patients with diabetes who undergoing percutaneous coronary intervention (PCI) has not been fully clarified.

Methods

A total of 1,069 consecutive patients with diabetes who underwent PCI were enrolled and divided into 2groups: oral hypoglycemic agents (OHA) group (709 patients) and insulin therapy group (360 patients). The primary and secondary endpoints of this study were all-cause death and cardiac death, respectively.

Results

At baseline, the maximum creatine kinase-MB (CK-MB), plasma glucose, hemoglobin A1c, high-sensitivity C-reactive protein (CRP), and creatinine levels were higher, while the left ventricular ejection fraction (LVEF) was lower, in the insulin therapy group than in the OHA group. After propensity score matching of baseline characteristics, for patients treated with insulin, the odds ratios of death from any cause in hospital, within 1 year of surgery, and within 2 years of surgery were 12.03 (95% CI: 1.486–97.33, P=0.020), 10.33 (95% CI: 1.21–88.12, P=0.033), and 2.99 (95% CI: 1.22–7.31, P=0.016), respectively, and the odds ratios of cardiac death were 10.33 (95% CI: 1.21-88.12, P=0.033), 6.49 (95% CI: 1.33–31.59, P=0.021), and 5.27 (95% CI: 1.45–19.13, P=0.011), respectively. Generalized estimating equations analysis showed the odds ratios of all-cause death and cardiac death for insulin-treated patients to be 4.77 (95% CI: 1.76–12.95, P=0.002) and 5.38 (95% CI: 1.29–22.96, P=0.023), respectively.

Conclusions

Compared with OHA, insulin therapy significantly increases the risk of in-hospital all-cause and cardiac death in patients with diabetes undergoing PCI, and the risk remains significantly at least 2 years after surgery.

Impact of diabetes mellitus on clinical characteristics, management, and in-hospital outcomes in patients with acute myocardial infarction (from the NCDR)

Patients with diabetes mellitus (DM) presenting with acute myocardial infarction (AMI) have worse outcomes versus those without DM. Comparative contemporary data in patients presenting with AMI with insulin-requiring diabetes mellitus (IRDM), noninsulin-requiring diabetes mellitus (NIRDM), and newly identified DM (hemoglobin A1C level >6.5%) versus patients without DM are limited. This observational study from the National Cardiovascular Data Registry (NCDR) Acute Coronary Treatment and Intervention Outcomes Network-Get with the Guidelines (ACTION Registry-GWTG consisted of 243,861 patients with AMI from 462 US sites identified from January 2007 to March 2011 entered into the registry. Clinical characteristics, management, and in-hospital outcomes were analyzed. Patients with DM with non-ST-segment elevation myocardial infarction (NSTEMI; n = 53,094, 35%) were less likely to undergo diagnostic angiography or revascularization, whereas those with ST-segment elevation myocardial infarction (STEMI) (n = 21,507, 23%) were less likely to undergo reperfusion therapy compared with patients without DM. There was an increased adjusted risk of in-hospital mortality in the DM group in both the NSTEMI (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.06 to 1.22) and STEMI (OR 1.17, 95% CI 1.07 to 1.27) population. In patients with DM, the risk-adjusted in-hospital mortality was higher in patients with IRDM than those with NIRDM in the NSTEMI group (OR 1.12, 95% CI 1.01 to 1.24) but not in the STEMI group (OR 1.12, 95% CI 0.95 to 1.32). Newly diagnosed patients with DM presenting with AMI had similar unadjusted in-hospital outcomes compared with patients without DM. In conclusion, patients with DM presenting with AMI have a higher mortality risk than patients without DM. In patients with DM, those with IRDM presenting with NSTEMI had an increased mortality than those with NIRDM.