Improved blood cellular biocompatibility with heparin coated circuits during cardiopulmonary bypass

Background: The clinical use of heparinized surfaces in the extracorporeal circuit was studied to find out if there was any blood cell theologic benef it to support its use in routine low risk cardiac surgery. Methods. In a prospective single blind study, 39 patients were operated upo n with the heart lung machine for angina pectoris by coronary bypass grafti ng and were randomized to a control group or a heparin group. Blood cell rh eology was analysed using the St. George filtrometer where damage to the re d blood cells and white blood cells was estimated by assessing deformabilit y reductions, transit, time increases and clogging rate and clogging partic le changes. Results. At the end of cardiopulmonary bypass, in the heparin group, the re d cell filterability (rFR) and the white cell filterability (WFR) were 8% b etter than in the control group (p = 0.0079 and p = 0.027 respectively). Th e red cell transit time was 19% slower in the control group (p = 0.0351), T he red cell clogging rate (RCR) and clogging particles (RCP) were significa ntly lower in the heparin group (p = 0.0212 and p = 0.0409 respectively. Th e white cell clogging rate (WCR) and clogging particles (WCP) showed a simi lar pattern. Conclusions. In spite of these significant differences the clinical outcome was similar in the groups. Thus heparin coating of the extracorporeal circ uit reduces blood cell theologic damage significantly in low risk patients undergoing routine bypass surgery for angina but this use did not lead to a ny clinical benefit postoperatively. Therefore the use of such circuits for routine low risk cardiac surgery cannot be recommended.