A clinical evaluation of remote ischaemic preconditioning for organ protection

Abstract

Periprocedural complications are an issue for patients with cardiovascular disease. Remote ischaemic preconditioning (RIPC) may offer periprocedural organ protection. Although the proof of concept data underpinning RIPC are encouraging, there are few data regarding clinical endpoints. The first component of this thesis comprises a literature review that explores the history and current status of RIPC with a focus on cardiovascular interventions. This is followed by two systematic reviews and meta-analyses. The first review examined the role of RIPC in percutaneous coronary intervention (PCI) and found a significant reduction in periprocedural myocardial infarction (MI) rates with RIPC, although the number of included patients was small. The second review examined the role of RIPC in the prevention of major clinical complications following cardiovascular surgery and found no significant effect although MI rates were reduced almost by half with RIPC. Heterogeneity of the studies and small individual sample sizes were likely to have rendered the meta-analysis underpowered. The remainder of the thesis comprises two pilot clinical trials. The first examined RIPC as a renoprotective strategy following contrast-enhanced computed tomography scanning. It demonstrated feasibility and it found that RIPC may have reduced kidney injury in those with impaired renal function but it found no evidence for a benefit across the whole cohort. The second trial examined RIPC in the setting of major vascular surgery in three centres. It found no significant effect on clinical outcomes or on troponin leakage following surgery although it demonstrated feasibility. The meta-analyses generated new data on the pooled effects of RIPC, thereby encouraging further clinical studies. The trials demonstrated feasibility and yielded data to guide future studies. RIPC represents an attractive and cheap risk reduction tool. If convincing data on patient important outcomes can be generated, it will become widespread.