Testing the Value of Novel Strategy and Its Cost Efficacy in Order to Improve the Poor Outcomes in Cardiogenic Shock

The EURO SHOCK trial tests the novel use of early deployment of mechanical support device in Cardiogenic Shock (CGS) in a randomised, strategy trial, with evidence of benefit or otherwise measured by recording hard clinical end-point outcomes.

Extra Corporeal Membrane Oxygenation (ECMO) is already used in CGS. This is therefore not a novel therapy. It is the use of ECMO early in the development of CGS that is the novel aspect of this project. The Investigators will test whether a strategy of very early ECMO can ameliorate the rapid decline that many CGS patients suffer. The value of deploying a clinically used and approved device prospectively and early in the natural history of CGS compared to standard practice has not been tested before and will be the basis of the EURO SHOCK project.

This trial itself will be a prospective randomized, open label, design study that will compare two groups of patients: Both will receive appropriate percutaneous coronary intervention (PCI) as is current practice as they arrive at the hospital.

1. Group 1 will receive immediate PCI + standard care (pharmacological support).

2. Group 2 will receive immediate PCI plus support with early peripheral veno-arterial ECMO

   • standard care (pharmacological support).

The Investigators will also compare the cost-effectiveness of early VA-ECMO, as compared to current standard of care. EURO SHOCK will also evaluate novel CMR protocols in these unwell patients, and also whether systems of urgent flagged transfer of the unwell patient is practical and beneficial. The Investigators will determine whether there are biological and ECG markers that predict worse patient outcomes, which could thus help select most appropriate patients for expedited treatments (the patient is only transferred if needed).

Although at the centre of the project there is a randomised trial, other important objectives will therefore be delivered.

The research study will additionally focus, through a-priori, post-hoc analyses, on higher risk and vulnerable sub groups such as the elderly (>75 years) and females, the importance of site of infarct and on those with multi-morbidities such as diabetes. These post-hoc data will be published separately.

The trial will include patients with out of hospital cardiac arrest (OHCA) who have documented return of spontaneous circulation (ROSC) but with certain caveats (see exclusion criteria).

The primary outcome is the all-cause mortality at 30 days following admission with acute coronary syndrome with cardiogenic shock. Key secondary outcomes will include all- cause mortality or admission with heart failure at 12 months, all-cause mortality at 12 months and admission to hospital with heart failure at 12 months.

A cornerstone of this research programme will be to determine the cost-efficacy of ECMO in this setting. Cost benefit will be measured both immediately and in the longer term testing for example any impact of need for heart failure therapies. This will be undertaken with evaluations of the cost-effectiveness of the device and evaluation of quality of life using the EuroQuol-5D-5L and the Minnesota Living with Heart Failure Questionnaire.

The EUROSHOCK trial will also include the following sub-studies:

1. Cardiovascular MRI: Cardio-Renal Imaging Sub-study using novel shortened, non-breath-holding protocols.

2. Platelet Function Sub-study designed to access the impact of novel ECMO coatings on platelet activation.

The programme will be developed and run through a carefully thought through management structure comprising 8 separate but interlinked work programmes (each targeted at one aspect of the project and headed by an experienced clinical trialist or trial manager) and involve the dissemination of results through a designated dissemination work package. Attention to translating the results to subsequent on-the-ground patient care will be an important aim for the management and dissemination team, and will involve patient support groups, professional societies and information delivered directly to the medical and non- medical staff caring for CGS patients.