A Prospective Randomized Blinded Trial of Remote Ischemic Preconditioning in Children Undergoing Cardiac Surgery.

ABSTRACT

Remote ischemic preconditioning (RIPC) has been proposed as an intervention to protect myocardium and attenuate end-organ dysfunction associated with cardiopulmonary bypass. We investigated the effect of RIPC in children undergoing cardiopulmonary bypass involving clinical outcome, cardiac and end-organ function, inflammatory response, and myocardial gene expression. A prospective, investigator-blinded, randomized, controlled trial was performed. Patients were randomized into RIPC or Control; RIPC consisted of three 5-minute cycles of limb ischemia-reperfusion taking place 1 and 12 hours preoperatively. Clinical outcomes included cardiac function, ICU surveillance, and renal function. In addition, inflammatory markers and myocardial gene expression were evaluated. RIPC patients required shorter ICU stay (days), RIPC 1.8 (0.94-3.88) vs Control 4.9 (1.63-7.20), P = 0.029. Echocardiography parameters demonstrated reduced biventricular function following surgery showing no difference between groups. A nonsignificant trend for reduced troponin was observed following RIPC AUC analysis, RIPC 393.05 (98.85-1038.73) vs Control 596.10 (225.38-954.24) P = 0.75. B-type natriuretic peptide and renal function parameters were similar between groups. Postoperative TNF-α was significantly reduced after RIPC, RIPC 15.42 (7.81-114.86) vs Control 108.98 (42.28-301.19) P = 0.02. Remaining inflammatory markers demonstrated no significant difference between groups. HSP-60 showed lower myocardial expression following RIPC, RIPC 3.95 (2.69-6.28) vs Control 6.83 (4.74-8.81), P = 0.05. Expression of other analyzed genes was not influenced by RIPC. RIPC was associated with shorter ICU stay and reduced TNF-α but did not influence other clinical outcomes, not confer protection against cardiac injury or renal dysfunction. The association between RIPC and ICU stay may be influenced by unaccounted latent variables, including cardiac morphology.