Effects of ischaemic conditioning on major clinical outcomes in people undergoing invasive procedures: systematic review and meta-analysis

Abstract

Objective To summarise the benefits and harms of ischaemic conditioning on major clinical outcomes in various settings.Design Systematic review and meta-analysis.Data sources Medline, Embase, Cochrane databases, and International Clinical Trials Registry platform from inception through October 2015.Study selection All randomised controlled comparisons of the effect of ischaemic conditioning on clinical outcomes were included.Data extraction Two authors independently extracted data from individual reports. Reports of multiple intervention arms were treated as separate trials. Random effects models were used to calculate summary estimates for all cause mortality and other pre-specified clinical outcomes. All cause mortality and secondary outcomes with P<0.1 were examined for study quality by using the GRADE assessment tool, the effect of pre-specified characteristics by using meta-regression and Cochran C test, and trial sequential analysis by using the Copenhagen Trial Unit method.Results 85 reports of 89 randomised comparisons were identified, with a median 80 (interquartile range 60-149) participants and median 1 (range 1 day-72 months) month intended duration. Ischaemic conditioning had no effect on all cause mortality (68 comparisons; 424 events; 11 619 participants; risk ratio 0.96, 95% confidence interval 0.80 to 1.16; P=0.68; moderate quality evidence) regardless of the clinical setting in which it was used or the particular intervention related characteristics. Ischaemic conditioning may reduce the rates of some secondary outcomes including stroke (18 trials; 5995 participants; 149 events; risk ratio 0.72, 0.52 to 1.00; P=0.048; very low quality evidence) and acute kidney injury (36 trials; 8493 participants; 1443 events; risk ratio 0.83, 0.71 to 0.97; P=0.02; low quality evidence), although the benefits seem to be confined to non-surgical settings and to mild episodes of acute kidney injury only.Conclusions Ischaemic conditioning has no overall effect on the risk of death. Possible effects on stroke and acute kidney injury are uncertain given methodological concerns and low event rates. Adoption of ischaemic conditioning cannot be recommended for routine use unless further high quality and well powered evidence shows benefit.

Long‐term outcome following remote ischemic postconditioning during percutaneous coronary interventions—the RIP‐PCI trial long‐term follow‐up

“…It is possible that RIPre is more effective than RIPost. This may be supported by the observation that in a large meta‐analysis, ischemic preconditioning tends to have a more favorable effect on reducing myocardial injury compared to ischemic postconditioning . We expected at least a modest effect with RIPost in our study, which included a higher‐risk population, such as patients presenting with unstable angina in contrast to the CRISP study, which included only elective patients.…”

“…The beneficial effect of RIPre in the setting of PCI was also confirmed in meta‐analyses . However, in a large meta‐analysis that included application of ischemic conditioning in multiple settings, overall ischemic conditioning had no effect on major cardiovascular outcomes, and so far we have not witnessed the translation of ischemic conditioning into clinical practice …”

Prevention of acute kidney injury and protection of renal function in the intensive care unit: update 2017

“…Though several meta-analyses found a reduction of AKI [278, 279, 281–284, 286, 287, 289, 290] this was restricted to stage 1 AKI [289], or subgroups such as percutaneous coronary interventions [278, 279], or cardiac surgery with propofol-free anaesthesia [283]. The meta-analyses are limited by risk of bias, heterogeneity in definitions of AKI, low event rates and underestimation of influence of co-morbidities [283, 289]. Finally, a Cochrane review including studies on patients undergoing surgery could not show a benefit on renal outcomes [178] (ESM_2 Table S16).…”

Randomized clinical trial of remote ischaemic preconditioning versus no preconditioning in the prevention of perioperative myocardial infarction during open surgery for ruptured abdominal aortic aneurysm

“…A recent review addressed other effects of RIPC, including its influence on acute kidney injury and renal impairment among patients undergoing elective AAA repair. One study that looked at protective renal effects as the primary outcome found that RIPC had no significant impact on kidney damage, when assessed by serum creatinine levels and urinary output, whereas another reported a significant reduction in peak serum creatinine levels.…”

“…Patients undergoing coronary bypass surgery with induced RIPC in an upper extremity had a total reduction in levels of troponin by 43 per cent when measured by area under the curve, reflecting reduced perioperative myocardial ischaemia. The effects of RIPC in vascular surgery have been described previously. One randomized study showed that RIPC of the lower extremities during elective aortic surgery reduced the myocardial infarction (MI) rate from 27 to 5 per cent, and demonstrated a significant reduction in renal damage.…”