IN THE NEWS: Remote ischemic preconditioning and prevention of AKI post CABG

Remote ischemic preconditioning(RIPC)  has been used as a protective method from ischemic damage to distant organs.  Application of one or more brief cycles of nonlethal ischemia/reperfusion to an organ or tissue may protect a remote organ or tissue from a sustained episode of lethal ischemia/reperfusion.

In a recent study presented at Europe and published in JAMA,  Zarbock et al examine the effects of RIPC on the rate and severity of AKI in patients undergoing cardiac surgery. In a multicenter trial, 240 patients at high risk for AKI  were randomized to receive either RIPC  or sham control  after induction of anesthesia.

The amazing results showed that AKI was significantly reduced with RIPC (45/120; 37.5%) compared with control (63/120; 52.5%), with an absolute risk reduction (ARR) of 15%. Fewer patients received RRT after RIPC (7 [5.8%] vs 19 control [15.8%]; ARR, 10%) and RIPC reduced intensive care unit stay (3 vs 4 days). RIPC had no significant effect on myocardial infarction, stroke, or mortality.

A recent meta-analysis published in AJKD showed otherwise.  Mostly randomized trials were included ( 13) and total of >1300 patients. There was no differences in levels of post operative AKI and incidence of RRT, in hospital mortality and hospital stay.  A prior meta-analysis had shown similar results as well.

Can we start using this in clinical practice? It is innovative, inexpensive and easily possible.  But long terms risks and harms are not known. Clearly, there is significant risk of AKI post CABG and this might be the only preventive measure that we have that has come close to showing any benefit. 

As suggested by the editorial in JAMA, before RIPC is adopted for clinical use, the potential risks and adverse effects must be considered carefully.  

image source: circres.ahajournals.org