Impacts of sepsis-induced myocardial dysfunction on hemodynamics, organ function and prognosis in patients with septic shock

Abstract

To investigate the impacts of sepsis-induced cardiac dysfunction on hemodynamics, organ function and prognosis in the patients with septic shock. A prospective cohort study was conducted in 44 patients suffering from septic shock with the duration < 24 hours admitted to the Department of Critical Care Medicine of Peking University Third Hospital during June 2013 to June 2014. The patients were divided into two groups according to the left ventricular ejection fraction (LVEF) as recorded in echocardiogram at time of admission to the intensive care unit (ICU) as sepsis-induced myocardial dysfunction group (LVEF < 0.50, n = 11) and normal cardiac function group (LVEF ≥ 0.50, n = 33). The cardiac function evaluation and hemodynamics monitoring were performed with echocardiogram and pulse-induced contour cardiac output (PiCCO) on 1, 3, 7 days after the ICU admission. The plasma levels of the biomarkers of myocardial damage, troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured, and the parameters representing organ function and the 28-day prognosis were collected as well. On the ICU admission, central venous pressure (CVP) and left ventricular end-diastolic diameter (LVEDD) were obviously lower in normal cardiac function group than those of myocardial dysfunction group [CVP (mmHg, 1 mmHg = 0.133 kPa): 10 ± 4 vs. 14 ± 6, P < 0.05; LVEDD (mm): 45.0 ± 5.3 vs. 51.8 ± 7.1, P < 0.01], and there was no significant difference in other hemodynamic parameters between two groups. On the 3rd day, all the cardiac function and hemodynamic parameters showed no significant differences between the two groups. On the 7th day, the cardiac index (CI) and pulmonary vascular permeability index (PVPI) of normal cardiac function group were significantly higher than those of myocardial dysfunction group [CI (mL×s⁻¹×m⁻²): 63.3 ± 13.3 vs. 48.3 ± 10.0, P <0.05; PVPI: 1.5 (1.4, 1.9) vs. 1.1 (0.7, 1.1), P < 0.01], and no significant difference was found in the other parameters. The plasma levels of TnT and NT-proBNP were found to have no difference at three time points between two groups. There was no difference in the number or the extent of organ dysfunction, including lung, kidney, liver and coagulation system, between the groups at the time of ICU admission. There was no obvious difference in the 28-day survival rate between the myocardial dysfunction group and normal cardiac function group [81.8% (9/11) vs. 72.7% (24/33), χ² = 0.398, P = 0.528]. Sepsis-induced myocardial dysfunction is a reversible organ dysfunction. It can directly induce decreased left ventricular systolic function and enlargement of ventricle in patients with septic shock without reducing cardiac output or impairing the functions of other organs, or elevating the mortality rate.