Timmer et al, studied the effect of admission stress hyperglycemia and that of chronic hyperglycemia (elevated levels of HbA1c in patients with undiagnosed diabetes mellitus) on ST-elevation myocardial infarction patients undergoing primary percutaneous coronary intervention; both elevated glucose and HbA1c levels were associated with adverse outcomes. However elevated glucose but not elevated HbA1c was associated with larger enzymatic infarct size and high early mortality.