Predictors of low perioperative cardiac output in patients with heart valve surgery

Abstract

Introduction: The perioperative low cardiac output syndrome (LCOS) is a frequent complication in the postoperative period of cardiac surgery which decreases short-term survival. Objectives: To determine the variables that independently predict the incidence of LCOS in the perioperative period of heart valve surgery at the Instituto de Cardiología y Cirugía Cardiovascular, during the 2012-2014 triennium. Method: A cohort study was conducted where two groups were formed: one with LCOS (46 patients) and the other without it (110 patients). A Kaplan-Meier curve was performed to determine survival 30 days after surgery. The groups were compared with the log-rank test. A multivariate analysis was carried out to determine the variables that independently influenced the appearance of LCOS. The level of statistical significance used was p<0.05. Results: The sample was homogeneous according to clinical and demographic characteristics. The incidence and mortality of the LCOS were 29.5% and 28.3%, respectively. Preoperative renal dysfunction (OR=5.13, p=0.005), prolonged extracorporeal circulation time (OR=4.89, p=0.001) and elevated pulmonary vascular resistance (OR=7.52, p<0.001) were the variables independently associated with the appearance of low cardiac output. Conclusions: The LCOS significantly reduces perioperative survival. Preoperative renal dysfunction, prolonged extracorporeal circulation and elevated pulmonary vascular resistance were variables of worse prognosis in these patients, associated with a higher probability of suffering this complication.