Cardiac macrovascular complications are a significant concern in individuals with diabetes mellitus, stemming from the disease’s profound impact on cardiovascular health. Diabetes accelerates the development of atherosclerosis, characterized by the buildup of plaque within arterial walls, which can lead to coronary artery disease (CAD), myocardial infarction (heart attack), and stroke. The underlying mechanisms involve chronic hyperglycemia, which promotes oxidative stress, inflammation, and endothelial dysfunction, contributing to the initiation and progression of vascular damage. Additionally, diabetes often coexists with other cardiovascular risk factors such as hypertension, dyslipidemia, and obesity, further compounding the risk of macrovascular complications. Management strategies focus on aggressive control of blood glucose levels, along with treatment of hypertension and dyslipidemia, to mitigate these risks. Lifestyle modifications, including smoking cessation, adoption of a heart-healthy diet, regular exercise, and adherence to prescribed medications, are crucial in reducing the incidence and severity of cardiac macrovascular complications in individuals with diabetes mellitus.