Avaliação do potencial prognóstico da anemia e do RDW na estratificação de risco em pacientes com síndrome coronariana aguda

Abstract

Ischemic heart diseases stands out among the diseases that affect the cardiovascular system due to its high prevalence and its impact on mortality in the general population. Ischemic heart disease is the leading worldwide cause of mortality. Fenomenum that also happens in the Americas and Brazil. The term acute coronary syndrome (ACS) is used to describe a heterogeneous spectrum of clinical conditions associated with acute myocardial ischemia, including unstable angina and acute myocardial infarction (AMI). The plurality in its clinical presentation represents a diagnostic challenge for clinicians. Moreover, appropriate risk stratification is mandadatory in all patients with ACS. Some clinical tools such as physical examination, electrocardiographic observations and risk scores are extremely usefull to identify patients at high risk of unfavorable clinical outcomes. Scores of risk stratification, among those the Global Registry of Acute Coronary Events (GRACE), are widely used in the prognostic evaluation of patients with ACS.Some plasma biomarkers have also been used to improove risk stratification. The GRACE score is a fundamental part of the assessment of patients with ACS and may even prevent or minimize adverse consequences in these individuals. Nevertheless, the search for new potential prognostic parameters that could add information to these establised scores has been the subject of intense research. In this context, stands out the use of routine hematological tests , since the complete blood count is readily available for clinical use and has a good cost-benefit relationship. Recent studies have investigated the potential role of some of red cell indices, especially anemia and red cell distribution width (RDW), in the prognostic evaluation of patients with several cardiovascular conditions. The presence of anemia and elevated RDW in patients with ACS have been independently associated with increased risk of adverse events such as heart failure, recurrent ischemic events, and death. We have hipotezazed that the addition of the hemalological indices to the GRACE score would improve its ability to stratify patients.The main objective of this study was to investigate whether inclusion of anemia or RDW, assessed at admission, in the GRACE score model to predic in-hospital mortality, could improve the discrimination and calibration of these model, as well as risk stratification in patients with ACS. For this, a cohort study, including 109 patients with AMI was carried out. Cox regression models including the variables of the GRACE score and RDW or anemia were constructed. Measures of calibration and discrimination, and reclassification of patients were also calculated for the new models. The new models, either with the inclusion of anemia, or the addition of RDW showed adequate calibration and discrimination. Furthermore, the addition of these parameters to the original model allowed adequate reclassification of patients in different categories of risk. The red cell indices, anemia and RDW showed potential prognostic for use in risk assessment of patients with ACS, allowing the improvement of risk stratification performed through the GRACE score.