Remote ischemic preconditioning reduces kidney injury after cardiac surgery

Remote ischemic preconditioning for patients at high risk for kidney injury undergoing cardiac surgery reduced the rate of acute kidney injury and use of renal replacement therapy, researchers reported at the European Renal Association/European Dialysis and Transplant Association Congress.

According to the study background, there is a lack of interventions to reduce risk for acute kidney injury in the setting of cardiac surgery. A team of researchers investigated whether remote ischemic preconditioning would accomplish the task.

Alexander Zarbock, MD, from the department of anesthesiology, critical care medicine and pain therapy at University Hospital Münster, Germany, and colleagues enrolled 240 patients (mean age, 70 years; 63% men) at high risk for kidney injury, defined as a Cleveland Clinic Foundation score of 6 or higher. From August 2013 to June 2014, patients at four centers in Germany were assigned to receive remote ischemic preconditioning, including three cycles of 5-minute ischemia and 5-minute reperfusion in an upper arm after induction of anesthesia, or sham remote ischemic preconditioning, both via BP-cuff inflation.

The primary endpoint was rate of acute kidney injury within the first 72 hours after cardiac surgery. Secondary endpoints included use of renal replacement therapy, ICU stay, stroke incidence, MI incidence, in-hospital mortality, 30-day mortality and change in acute kidney injury biomarkers. All patients completed 30-day follow-up.

Acute kidney injury reduced

Patients who received remote ischemic preconditioning had a lower rate of acute kidney injury compared with controls (37.5% vs. 52.5%; absolute risk reduction, 15%; 95% CI, 2.56-27.44).

Use of renal replacement therapy was reduced in the remote ischemic preconditioning group compared with controls (5.8% vs. 15.8%; absolute risk reduction, 10%; 95% CI, 2.25-17.75).

Remote ischemic preconditioning also was associated with a shorter ICU stay (3 days vs. 4 days; P = .04).

However, there were no significant differences between the groups for MI, stroke or mortality.

According to the researchers, remote ischemic preconditioning attenuated the release of urinary insulin-like growth factor-binding protein 7 and tissue inhibitor of metalloproteinases-2 after surgery (0.36 ng/mL²/1,000 vs. 0.97 ng/mL²/1,000; difference, 0.61; 95% CI, 0.27-0.86).

Zarbock and colleagues reported that no adverse events were reported with remote ischemic preconditioning.

Novel solution

Remote ischemic preconditioning “may offer a novel inexpensive and noninvasive clinical intervention to reduce the occurrence and severity of [acute kidney injury],” Jenny Szu-Chin Pan, MD, and David Sheikh-Hamad, MD, from the section of nephrology of the department of medicine at Baylor College of Medicine, Houston, wrote in a related editorial in JAMA.

Pan and Sheikh-Hamad, cautioned, however, that “effects of repeated limb ischemia with [remote ischemic preconditioning] are not known and clinicians should be mindful of potential harms before adopting this approach widely.” – by Erik Swain

References:

Pan JS, Sheikh-Hamad D. JAMA. 2015;doi:10.1001/jama.2015.5085.

Zarbock A, et al. JAMA. 2015;doi:10.1001/jama.2015.4189.

Zarbock A, et al. Late Breaking Clinical Trials. Presented at: European Renal Association/European Dialysis and Transplant Association Congress; May 28-31, 2015; London.

Disclosures: Zarbock reports receiving grant support and consultant fees from Astute Medical. Another researcher reports receiving grant support and consultant fees from Alere and Astute Medical. Pan and Sheikh-Hamad report no relevant financial disclosures.