Has hyperglycemia a different prognostic role in STEMI patients with or without diabetes?

Background and aims: Hyperglycemia at hospital admission is a common finding in patients with STEMI. However, whether elevated acute glycemia in these patients may have a direct impact on worsening prognosis or is just a marker of a greater neurohormonal activation in response to the infarction is still unsettled. We sought to investigate the prognostic impact of hyperglycemia at hospital admission in patients undergoing primary PCI (pPCI) for STEMI, and the influence of the presence of diabetes mellitus (DM) on its prognostic impact. Methods: and Results, We enrolled 2958 consecutive STEMI patients treated by pPCI. Hyperglycemia was defined as plasma glucose >198 mg/dL (or >11 mmol/L). Patients with hyperglycemia showed a greater risk-profile; they also experienced a higher mortality both at univariable (17.6% vs 5.2%, p < 0.001) and multivariable (HR 1.9, 95%IC 1.5–2.9, p = 0.001) analysis. However, after stratification for DM presence, hyperglycemia resulted as an independent predictor of mortality only in patients without DM (HR 2, 95%IC 1.2–3.4, p = 0.01). Conclusion: Hyperglycemia in the setting of myocardial infarction treated with primary PCI in an independent predictor of all-cause mortality in patients without diabetes; in patients with diabetes, its prognostic impact seems attenuated.