Effect of Remote Ischaemic Preconditioning on Clinical Outcomes in CABG Surgery

Effect of Remote Ischaemic Preconditioning on Clinical Outcomes in Coronary Artery Bypass Graft Surgery

Coronary heart disease (CHD) is the leading cause of death in the UK, accounting for 124,000 deaths (2006) and costing the UK economy over £7.9 billion a year. Patients with severe CHD are usually treated by coronary artery bypass graft (CABG) surgery, the risks of which are increasing due to older and sicker patients being operated on. New treatment strategies are therefore required to improve health outcomes in these high-risk patients undergoing CABG with or without valve (CABG±valve) surgery.

The hypothesis tested in this research proposal is that remote ischaemic preconditioning (RIC), a virtually cost-free, non-pharmacological and simple non-invasive strategy for reducing the damage to the heart muscle at the time of surgery, improves health outcomes in high-risk patients undergoing CABG±valve surgery.

In this research project, 1610 high-risk patients undergoing CABG±valve surgery will be recruited via 28 UK hospitals performing heart surgery. Patients will be randomly allocated to receive either RIC or control. For RIC, a blood pressure cuff will be placed on the upper arm to temporarily deprive it of oxygen and nutrients, an intervention which has been shown in the investigators pilot studies to reduce damage to the heart muscle by up to 40% during CABG±valve surgery. The investigators will determine whether RIC can improve health outcomes in terms of better patient survival, less heart attacks and strokes, shorter hospital stay; less damage to the heart, kidney and brain during surgery; better heart function post-surgery and less chance of developing heart failure; better exercise tolerance and quality of life.

Inclusion Criteria:

1. Patients undergoing CABG with or without valve surgery using blood cardioplegia
2. Patients aged 18 years and above
3. Patients with an additive Euroscore greater than or equal to 5

Exclusion Criteria:

1. Cardiogenic shock
2. Cardiac arrest on current admission
3. Pregnancy
4. Significant peripheral arterial disease affecting the upper limbs
5. Patients with significant hepatic dysfunction (Prothrombin>2.0 ratio)
6. Patients with significant pulmonary disease (FEV1<40% predicted)
7. Patients with known renal failure with a GFR<30 mL/min/1.73 m2
8. Patients on glibenclamide or nicorandil, as these medications may interfere with RIC
9. Patients recruited into another study which may impact on the ERICCA study