Application of a simplified definition of diastolic function in severe sepsis and septic shock

Abstract

Background: Left ventricular diastolic dysfunction is common in patients with severe sepsis or septic shock, but the best approach to categorization is unknown. We assessed the association of common measures of diastolic function with clinical outcomes and tested the utility of a simplified definition of diastolic dysfunction against the American Society of Echocardiography (ASE) 2009 definition.

Methods: In this prospective observational study, patients with severe sepsis or septic shock underwent transthoracic echocardiography within 24 h of onset of sepsis (median 4.3 h). We measured echocardiographic parameters of diastolic function and used random forest analysis to assess their association with clinical outcomes (28-day mortality and ICU-free days to day 28) and thereby suggest a simplified definition. We then compared patients categorized by the ASE 2009 definition and our simplified definition.

Results: We studied 167 patients. The ASE 2009 definition categorized only 35 % of patients. Random forest analysis demonstrated that the left atrial volume index and deceleration time, central to the ASE 2009 definition, were not associated with clinical outcomes. Our simplified definition used only e' and E/e', omitting the other measurements. The simplified definition categorized 87 % of patients. Patients categorized by either ASE 2009 or our novel definition had similar clinical outcomes. In both definitions, worsened diastolic function was associated with increased prevalence of ischemic heart disease, diabetes, and hypertension.

Conclusions: A novel, simplified definition of diastolic dysfunction categorized more patients with sepsis than ASE 2009 definition. Patients categorized according to the simplified definition did not differ from patients categorized according to the ASE 2009 definition in respect to clinical outcome or comorbidities.

Keywords: Classification; Diastolic; Echocardiography; Sepsis; Shock.

Fig. 1

a American Society of Echocardiography (ASE 2009) definition of diastolic dysfunction [15]. The difference in duration flow between atrial reversal of flow and atrial inflow in late diastole duration and change in early diastolic velocity of mitral inflow (E) to late diastolic velocity of mitral inflow (A) with Valsalva were omitted, given the difficulty in acquiring these measurements in this patient population. b Simplified definition of diastolic dysfunction. This is a subset of the parameters presented in the ASE 2009 guidelines. The thresholds used to categorize patients by grade are based on those presented in the ASE guidelines, but have been simplified to include all possible values. Septal e′ early peak velocity of septal mitral annulus, LAVI left atrial volume index, DT mitral deceleration time

Fig. 2

Flowchart representing patient selection. ICU intensive care unit, ASE American Society of Echocardiography