Abstract 11473: Renal and Cardiac Effects of Remote Ischemic Preconditioning in Children Undergoing Cardiopulmonary Bypass Surgery

Abstract

Introduction: Children undergoing cardiac surgery are at risk for AKI and cardiac dysfunction affecting outcome. Improved surgical techniques and post-operative care allow better outcomes in complex repairs and at-risk patients. Opportunity exists in further protecting multiple end organ function with remote ischemic preconditioning (RIPC) given promising but mixed data in adults and children. Hypothesis: A non-invasive technique of inducing reversible lower extremity ischemia with inflation of pressure cuff lessens renal and myocardial injury. Methods: A single center randomized, placebo controlled, double blinded trial of RIPC in children undergoing cardiac surgery of RACHS-1 category 2 or greater. RIPC was performed in the operating room after anesthesia and before sternotomy. Pre-specified end points are change in creatinine, eGFR, development of AKI, B-type natriuretic peptide and Troponin I at 6, 12, 24, 48, 72 hours post separation from bypass. Secondary end points included select clinical outcomes. Results: There were 45 in the RIPC and 39 patients in the control group: age was 3.5 and 3.8 years, respectively; 57 patients below 1 year of age; 35 patients below 1 month of age. There was no difference between groups in creatinine, cystatin C, eGFR at each time points. There was a trend for a larger rate of decrease, especially for cystatin C (p=0.042) in the RIPC group but the magnitude was small. AKI was observed in 21 (54%) of control and 16 (36%) of RIPC group (p=0.094). Adjusting for baseline creatinine, the odds ratio for AKI in in RIPC compared to control group was 0.31 (p=0.037). Adjusted for clinical characteristics, the odds ratio was 0.34 (p=0.056). Peak troponin occurred at 6 hrs. Compared to control, the RIPC group had a lower troponin at 6 hrs (p=0.140). However, no difference in other analyses of troponin and B-type natriuretic peptides between the groups. Length of stay, all-cause mortality, systolic function by echocardiography and composite clinical end points of advanced renal and heart failure were not different between groups. Conclusions: There is suggestion of RIPC delivering renal protection in an at-risk pediatric population. Additional larger, higher risk population studies will be required to fully determine its efficacy.