Glucose-Lowering Targets for Patients With Cardiovascular Disease

Abstract

The observation that elevated glucose levels can occur in patients hospitalized with acute coronary syndromes (ACS) was made many decades ago.1 Since then, a multitude of studies have documented that hyperglycemia is common, affects patients with and without established diabetes mellitus, and is associated with adverse outcomes, with a graded increase in the risk of mortality and complications across the spectrum of glucose elevations observed.2,–,26 However, a number of critical gaps in knowledge remain. These include, first and foremost, a better understanding of whether glucose level is simply a risk marker of greater illness severity or a risk factor with a direct causal relationship to the observed adverse outcomes in patients with ACS. Similarly, it remains unclear whether interventions to lower glucose in patients with ACS (unstable angina, non–ST-segment elevation myocardial infarction [MI], and ST-segment elevation MI) can improve survival and other outcomes and, if so, what the optimal targets, therapeutic strategies, and timing for such interventions should be during ACS. In this article, we will review current knowledge about the association between glucose levels and outcomes of patients hospitalized with ACS; describe the available data with regard to inpatient glucose management in patients with ACS, as well as comparative data across the clinical spectrum of critically ill hospitalized patients; address the controversies in this field; and offer practical recommendations for patient management based on the existing data. Although hyperglycemia occurs commonly in hospitalized patients with cardiovascular disease conditions other than ACS, the relationship between glucose levels and outcomes has not been well studied among those patient populations. Therefore, the emphasis of this review will be on the care of patients with ACS. There is currently no uniform definition of hyperglycemia in the setting of ACS. Prior studies used various hyperglycemia cut points, ranging …