ABC | Volume 113, Nº4, October 2019

Updated Updated Cardiovascular Prevention Guideline of the Brazilian Society Of Cardiology – 2019 Arq Bras Cardiol. 2019; 113(4):787-891 no longer compensates its resistance. After this moment, the diagnosis will be established by hyperglycemia, but CV changes adaptive to insulin resistance and cellular oxidative stress become irreversible. Another mechanism that seems to occur even in early stages (pre-hyperglycemia) is the accumulation of fatty acids in various tissues, such as pancreas, heart, and liver, accelerating the dysfunction in insulin production, hepatic glucose production, and left ventricular diastole. 73 Therefore, even remotely before the period of hyperglycemia, several cellular mechanisms cooperate to determine the endothelial dysfunction, the phenotypic changes in lipids with hypertriglyceridemia, and small, dense LDL, creating the ideal scenario for accelerated atherogenesis. 74 Together, these data suggest that CAD becomes accelerated many years before the onset of hyperglycemia. 3.2.2. Primary Prevention Strategies for Coronary Artery Disease in Individuals with Metabolic Syndrome and Diabetes Mellitus Corroborating the pathophysiological evidence, weight control strategies with physical activity and intensive dietary guidance have proven to be the best available method to reduce the risk of a patient with MS and pre-DM developing the clinical diagnosis of DM. 75,76 Lifestyle interventions decreased the risk for DM by 45% (p = 0.001), the risk for CV death by 41% (p = 0.033), and all-cause mortality by 29% (p = 0.049). In patients with established DM and microalbuminuria, the randomized clinical trial STENO-2 77 showed that a multifactorial approach to lifestyle significantly decreased CV morbidity and mortality in comparison with conventional treatment. 3.2.3. Individual Risk Prediction for Coronary Artery Disease in Patients with Diabetes Mellitus and Metabolic Syndrome At least 68% of diabetic patients aged 65 years or older die from heart diseases, most of them from CAD, followed by congestive HF. 78 DM is considered an independent CV risk factor both in men and women, raising in about two to four times the probability of clinical CAD, when compared to individuals without DM. 79 Moreover, based on a meta- analysis with almost 1 million individuals from 87 studies, MS is associated with a twofold increase in CV outcomes and a 1.5 increase in all-cause mortality, exceeding the isolated risk of its components. 80 The CAD risk in the population with DM or MS, however, is not evenly distributed. Several strategies for CAD screening were implemented in recent decades, although Figure 3.2 – Progression of micro- and macrovascular disease in type 2 diabetes and its relationship with the functional reserve of pancreatic beta-cells and hyperglycemia. Relative function (%) Years before diagnosis Years after diagnosis Pre-diabetes Severity of diabetes Insulin resistance Microvascular complications Macrovascular complications β-cell function 807