A clinical, renal and immunological assessment of Surface Modifying Additive Treated (SMART™) cardiopulmonary bypass circuits

Abstract

Biocompatible cardiopulmonary bypass (CPB) circuits aim to reduce contact activation and its physiological consequences. We investigated the hypothesis that use of Surface Modifying Additive (SMA)-treated circuits (Sorin Group Ltd) compared with non-SMA circuits would be associated with preservation of blood pressure during CPB and modulation of perioperative subclinical renal function (urinary α-1-microglobulin (α-1-m)) and plasma and urinary cytokine changes. In a study of low-risk CABG patients ( n=40), randomized to SMA ( n=20) versus non-SMA circuits ( n=20), we found better preserved blood pressure at CPB initiation in SMA patients (p <0.05), particularly in ACE-inhibited SMA patients ( n=11) versus ACE-inhibited non-SMA patients ( n=10) (p <0.05). Plasma anti-inflammatory IL-10, as well as urinary α-1-m, were elevated 48 hours postoperatively (p <0.05). SMA patients also had lower blood loss (p <0.05). SMA circuits have some clinical benefit, especially in ACE-inhibited patients.