Role of remote ischaemic preconditioning on myocardial injury in stable patients undergoing percutaneous coronary intervention: a randomised case-control study

Troponin release is a sensitive and specific marker of myocyte necrosis and infarction resulting from a form of ischaemia/reperfusion injury, downstream embolisation of atheromatous material, and coronary side branch occlusion. In addition to the strong diagnostic role of cardiac troponins, their prognostic value has become increasingly well established for patients presenting with acute coronary syndrome. The inflammatory response and enzyme leakage during coronary angioplasty is increasingly becoming a recognised issue. Elective percutaneous coronary intervention (PCI) is associated with troponin release in approximately one third of cases, and this troponin release is independently and significantly predictive of an increased risk of adverse events.

Transient sublethal episodes of ischaemia before a prolonged ischaemia/reperfusion injury, known as ischaemic preconditioning (IPC), have been shown to reduce the extent of myocardial injury.

Therefore, remote ischaemic preconditioning (RIPC) is a phenomenon in which brief episodes of  ischaemia followed by reperfusion in one organ seem to provide systemic protection from prolonged ischaemia in the myocardial muscle and also to limit the myocardial infarction (MI) size. This phenomenon has been observed in

an animal model13. IPC has been used during cardiac surgery. IPC has also been applied during angioplasty (regional vessel preconditioning) to reduce inflammation and enzyme leakage. A novel way to apply preconditioning via remote organ (e.g., limb) ischaemia reperfusion cycles has been described18. An added advantage is that the entire heart may thus be preconditioned, that is to say, globally, not regionally. RIPC has been shown to protect against endothelial ischaemia/reperfusion injury and the extent of MI after adult coronary bypass surger, paediatric surgery, and non-cardiac surgery. However, some studies failed to demonstrate a beneficial effect of RIPC during PCI.