Analysis of microRNAs Expression in Patients Who Evolved to Vasoplegic Syndrome After On-pump Coronary Artery Bypass Surgery

Cardiovascular diseases (CVD) are among the main causes of morbidity and mortality in the world, and in Brazil they account for approximately 31% of all causes of death and 42% of deaths due to noncommunicable diseases. In 2014 were carried out a total number of 92,000 heart surgeries in Brazil and these are usually performed using Cardiopulmonary Bypass (CPB), which is made by the diversion of blood circulation of the lungs and heart to a heart-lung machine, which keeps cardio circulatory functions and oxygenates the blood. Despite enable various types of major cardiac surgery, the use of CPB can cause serious side effects such as post perfusion vasoplegic syndrome (VS). This is characterized by increased cardiac output, hypotension, systemic inflammatory response and decreased vascular resistance, affecting 9-44% of patients in the postoperative period of cardiac surgery, with a mortality of 27%. Treatment to VS are limited and the drugs are often ineffective, including noradrenaline, vasopressin, and methylene blue. Another difficulty encountered by the surgeon is to establish a predictive factor for VS. Systems risk predictors that use score and are well validated as EuroSCORE (European System for Cardiac Operative Risk Evaluation) have not been tested for VS. Much has been studied on the use of biomarkers as predictors and for prognosis as well as to improve predictive power of the rating systems available. MicroRNAs (miRNAs) are noncoding RNA molecules that control gene expression in the intracellular environment and are present circulating in various body fluids including peripheral blood. These molecules can be used as biomarkers of various pathologies including CVD. Despite the existence of numerous studies that demonstrate the importance of miRNAs in the development of CVDs. There are no studies that address the issue in VS. Therefore, the objective of the project is to identify the presence of blood miRNAs that are altered in patients with pre and intra-operative cardiovascular surgery and assess whether these miRNAs can be used as predictors and biomarkers of mortality for VS.