IMPACT OF INTENSIVE GLYCEMIC CONTROL ON CARDIOVASCULAR OUTCOMES IN PATIENTS WITH TYPE 2 DIABETES MELLITUS AND ESTABLISHED CORONARY ARTERY DISEASE

Abstract

Introduction: Type 2 Diabetes Mellitus represents a major cardiovascular risk factor, and its coexistence with established coronary artery disease dramatically increases the likelihood of subsequent ischemic events and mortality. Strict glycemic control has historically emerged as a fundamental strategy to mitigate chronic complications of diabetes, particularly microvascular complications. However, the impact of intensive glycemic control on macrovascular outcomes, such as acute myocardial infarction, stroke or cardiovascular death, in patients who already had documented coronary artery disease, presented complexities and results that require in-depth investigation to guide clinical practices. Objective: The objective of this systematic literature review was to evaluate the impact of intensive glycemic control on major cardiovascular outcomes in patients with Type 2 Diabetes Mellitus and established coronary artery disease. Methodology: A systematic literature review was conducted following the PRISMA checklist guidelines. The search was performed in the PubMed, SciELO and Web of Science databases, using the descriptors: "Intensive Glycemic Control", "Diabetes Mellitus Type 2", "Coronary Artery Disease", "Cardiovascular Outcomes" and "Secondary Prevention". Articles published in the last 10 years that fit the theme were included. Inclusion criteria included studies in adult humans with T2DM and established CAD, comparing intensive versus standard glycemic control, which reported cardiovascular outcomes. Primary prevention studies, with other types of diabetes or that did not report major cardiovascular outcomes were excluded. Results: The studies analyzed demonstrated that, while intensive glycemic control was effective in reducing microvascular complications in this population, its benefits on macrovascular outcomes, such as infarction or non-fatal stroke, were less consistent and more modest compared to primary prevention. Some large trials have suggested an increased risk of severe hypoglycemia associated with tighter control, and one landmark study indicated an increase in all-cause mortality, raising concerns about the safety of extreme intensification in this high-risk group. Conclusion: Intensive glycemic control in patients with type 2 diabetes mellitus and established coronary artery disease showed limited benefit on major cardiovascular outcomes, in contrast to results in primary prevention. The therapeutic approach required a careful balance between the potential microvascular benefits and the increased risk of hypoglycemia and other adverse events, suggesting the need for individualization of glycemic targets in this clinical setting.