CharacterisatiON of carDiac funCTion in Intensive Care Unit Survivors of Sepsis.

CharacterisatiON of carDiac funCTion in Intensive Care Unit Survivors of Sepsis (CONDUCT-ICU): A Pilot Study

Cardiac dysfunction is common following hospital admission with sepsis and one of the most frequent causes for readmissions to hospital, however underlying mechanisms by which this might occur are unclear. The CONDUCT-ICU investigators will conduct a pilot, cohort study, characterizing cardiac function in ICU survivors of sepsis using a combination of CMR imaging, biomarkers and patient reported outcome measures to investigate mechanisms of cardiac dysfunction following sepsis. Comparisons will be made to that of the general population.

Sepsis is one of the most common reasons for admission to ICU in the UK and it is well established that adverse cardiovascular events are common following sepsis. In fact, the risk of adverse cardiovascular events such as MI, Heart Failure and Stroke is in excess of 60% greater compared to those who have not had sepsis. Similarly, heart failure is one of the most common causes of readmission to hospital following an episode of sepsis. The underlying mechanisms for this phenomenon are unclear and CONDUCT-ICU investigators intend on answering this question.

Investigators will collect cardiac and inflammatory biomarkers from participants at the point of discharge from ICU. Following discharge from hospital, cardiac magnetic resonance (CMR) scans of the heart will be undertaken in participants 6-10 weeks post-discharge from hospital to examine for evidence of inflammation in the heart. Further blood samples will also be collected to look for evidence of inflammation and heart muscle injury at this point in addition to patient reported outcomes measures using validated questionnaires.

Participants will be identified with their direct clinical team in ICU and are nearing or at the point of discharge from ICU. If eligible for the study, they will be approached by researchers and provided them with an information sheet and written consent form. Participants will be given up to 24hrs to decide if they wish to take part in research and if so, they will sign the consent form. Participants are free to withdraw from the study at any time, without any reason given, and this would not affect the standard of care they receive.

This is an observational cohort study. If willing to take part, participants will receive the normal follow-up that would be undertaken following discharge from ICU. In addition, researchers will collect a sample of blood from participants at the time of discharge from ICU and again at 6 -10 weeks post discharge. A Cardiac Magnetic Resonance (CMR) scan will be undertaken 6-10 weeks follow up.

Researchers will assess the patient's day-to-day function and quality of life by asking them to complete validated questionnaires. These questionnaires should take five to ten minutes to complete and help will be available if required. Participants will complete these questionnaires at the follow-up visit 6-10 weeks following discharge from hospital with the help of the researchers conducting the study

The first blood sample will be collected following discharge from ICU whilst the patient is still in hospital. Further blood samples will be collected 6-10 weeks following discharge from hospital. Blood samples for patients undergoing CMR will be taken when they attend for scan. Blood sampling for patients who do not undergo CMR imaging will attend for a separate follow-up visit for collection of samples.

Patients are normally invited to attend ICU follow-up via the InS:PIRE service at approximately 6-10 weeks post-discharge. Where possible researchers will combine blood sample analysis with routine follow-up visits in clinic to which participants would normally be invited. If they are not able to attend follow-up and are not attending for CMR scan, then researchers will invite them to the research facility within the local sites for collection of samples.

Samples will be stored in NHS Biorepository and analyzed within the British Heart Foundation Laboratory at the University of Glasgow.

Inclusion Criteria:

1. Provision of informed consent.
2. Age > 18 years.
3. ICU admission with sepsis (According to The Third International Consensus Definitions for Sepsis and Septic Shock [Sepsis-3])17
4. Ability to comply with study procedures

Exclusion Criteria:

1. Inability to give informed consent

2. Pregnancy.

3. Ongoing participation in any investigational research that may undermine the scientific basis of the study.

4. Contraindications to magnetic resonance imaging:

   i. Cardiac pacemaker, artificial heart valve, neurostimulator, cochlear implant ii. Aneurysm clips iii. Metal injuries to the eye iv. Loose metal in any part of the body v. Severe claustrophobia

5. Known Coronary Artery Disease

6. Previous Myocardial Infarction

7. Chronic Heart Failure prior to ICU admission

8. Patient receiving immune modulating drug or biologic therapy either long term or during acute admission

9. Patient considered by the clinical team to be very unlikely to survive to hospital discharge

10. Hospital Admission because of Covid-19

11. Patients undergoing treatment for malignancy with systemic anti-cancer therapies.