Postconditioning signalling in the heart: mechanisms and translatability

Area of Science:

• Cardiology
• Translational Medicine
• Pharmacology

Background:

• Ischaemic postconditioning, involving brief reperfusion/reocclusion cycles, emerged over a decade ago to mitigate reperfusion injury and infarct size in acute myocardial infarction.
• Understanding postconditioning mechanisms has revealed potential pharmacological targets, including specific receptor ligands, survival signaling pathways, and mitochondrial pore inhibitors.

Purpose of the Study:

• To evaluate the clinical efficacy of ischaemic postconditioning and its pharmacological mimetics in reducing reperfusion injury.
• To identify challenges hindering the translation of experimental findings into clinical practice.

Main Methods:

• Review of experimental and clinical studies on ischaemic postconditioning and pharmacological postconditioning mimetics.
• Analysis of factors influencing experimental model relevance and clinical trial design.

Main Results:

• Experimental models show promise for postconditioning agents, but clinical studies yield equivocal results.
• Animal models do not fully replicate human comorbidities and risk factors that modify postconditioning signaling.
• Clinical trial limitations include cohort size, patient selection, and infarct size estimation inaccuracies.

Conclusions:

• Translating postconditioning's benefits requires more complex experimental models that mimic clinical complexity.
• Larger, well-designed clinical trials with standardized infarct measurements and appropriate patient selection are crucial for assessing therapeutic efficacy.