The Assessment of Left Ventricular Function in Sepsis and Septic Shock

: Comparison of Ejection Fraction Measurement (both by two-dimensional and three-dimensional echocardiography), Global Longitudinal Strain, Troponin T and NT-ProBNP

Abstract

Sepsis and septic shock, and the sequelae of septic cardiomyopathy, are a common yet major concern in the intensive care unit and are associated with high mortality. Septic cardiomyopathy is traditionally identified with echocardiography, using left ventricular ejection fraction (EF), but accurate interpretation is challenging. This thesis summarises a six-year clinical investigation and evaluates alternative echocardiographic measures, such as global longitudinal strain (GLS) and biomarkers (NT-ProBNP or Troponin T), to detect septic cardiomyopathy.
Using echocardiography on days 1, 3, 30, and 90 from admission with sepsis found that despite a normal EF in many cases, GLS was commonly abnormal, and this finding persists beyond clinical recovery. No relationship between GLS and EF was found at any study stage, despite both being measurements of cardiac function. Whilst Troponin T and NT-proBNP were elevated on day 1 of the study in patients with sepsis, there was no correlation between these biomarkers and EF results. However, there was some correlation between GLS and NT-ProBNP.
A twelve-month follow-up for mortality and major adverse cardiovascular events revealed that sepsis-related death mostly happened in the first three days of hospitalisation. Despite the aberrant biomarker and GLS results at days 30 and 90, adverse cardiovascular events were rarely observed after discharge. A questionnaire explored what barriers echocardiographers face in implementing GLS into practice, given the potential for its usage in the field. Although most respondents agreed that GLS may have a role in improving patient outcomes, they listed time and training as the main obstacles to routine use.
This thesis adds to the current knowledge base by expanding the study period on septic cardiomyopathy to include echocardiography and biomarkers beyond discharge from the hospital. It shows that latent LV dysfunction cannot be predicted using admission data. There is a legacy of elevated biomarkers and abnormal GLS for up to 90 days post-sepsis in clinically recovered patients

Date of Award	13 Jun 2025
Original language	English
Awarding Institution	University of Portsmouth
Supervisor	Simon Kolstoe (Supervisor) & Margriet Johanna Susanna Woodhouse (Supervisor)