The Effect of Remote Ischaemic Preconditioning on Arterial Stiffness in Patients Undergoing Vascular Surgery: A Randomised Clinical Trial

Abstract

The main aim of this study was to evaluate the effect of remote ischaemic preconditioning (RIPC) on arterial stiffness in patients undergoing vascular surgery. This was a randomised, sham controlled, double blind, single centre study. Patients undergoing open abdominal aortic aneurysm repair, surgical lower limb revascularisation surgery or carotid endarterectomy were recruited. A RIPC or a sham procedure was performed, using a blood pressure cuff, along with preparation for anaesthesia. The RIPC protocol consisting of four cycles of 5min of ischaemia, followed by 5min of reperfusion was applied. Arterial stiffness and haemodynamic parameters were measured pre-operatively and 20-28h after surgery. Two primary outcomes were selected: augmentation index and pulse wave velocity. Ninety-eight patients were randomised. After dropouts 44 and 46 patients were included in the RIPC and sham groups, respectively. Both groups were comparable. There were no statistically significant differences in augmentation index (p=.8), augmentation index corrected for heart rate of 75 beats per minute (p=.8), pulse wave velocity (p=.7), large artery elasticity indices (p=.8), small artery elasticity indices (p=.6), or mean arterial pressure (p=.7) changes between the RIPC and sham groups. There occurred statistically significant (p≤.01) improvement in augmentation index (-5.8% vs.-5.5%), augmentation index corrected for a heart rate of 75 beats per minute (-2.5% vs.-2%), small artery elasticity indices (0.7mL/mmHg×100 vs. 0.9mL/mmHg×100), and mean arterial pressure post-operatively in both the RIPC and the sham groups (change median values in RIPC and sham groups, respectively). RIPC had no significant effect on arterial stiffness, but there was significant improvement in arterial stiffness after surgery in both groups. Arterial stiffness and haemodynamics may be influenced by surgery or anaesthesia or oxidative stress or all factors combined. Further studies are needed to clarify these findings. CLINICALTRIALS.GOV: NCT02689414.