We read with great interest the paper of Kumar et al1 published in the present edition of AsiaIntervention, as this is the first randomised clinical trial demonstrating the benefit of remote ischaemic preconditioning (RIPC) on the reduction of periprocedural myocardial infarction (PMI) after a percutaneous coronary intervention (PCI) in Indian patients.
Two main considerations may arise from the present work:
1) RIPC is not affected by ethnicity;
2) the benefit offered in patients undergoing PCI for stable angina seems consistent with data already reported in the literature.
Some animal studies that date back to almost twenty years ago have already postulated the beneficial effect of a “brief ischaemia”, both in the heart and in the non-cardiac tissues2,3. Recently, some steps towards clarifying the mechanism responsible for remote ischaemic preconditioning have been taken4-6. The signals seem to be transferred to the peripheral target organs through different pathways, involving both the somato-sensory and the autonomous nervous systems4. Both of them might carry the central inputs to the downstream extracellular specific receptors, and then, by intracellular signal transduction molecules, may cause changes in mitochondrial function4,5, as shown in Figure 1. Adenosine, bradykinin, and calcitonin gene-related peptide are probably important mediators in the afferent loop of this reflex2,3,6,7; however, the exact nature of the signal transduction from the remote tissue to the target organs remains to be fully clarified.