Heparin-bonded circuits versus nonheparin-bonded circuits: an evaluation of their effect on clinical outcomes

Heparinization of the blood contact surface in cardiopulmonary bypass circuits has been promoted as an important step in the development of open heart surgery. As it decreases the inflammatory response resulting from the extracorporeal circulation, it may have a positive effect on clinical outcomes. This meta-analysis was carried out to examine if heparin-bonded circuits (HBCs) reduce the need for blood products and improve overall clinical outcome. A systematic literature search was performed to identify randomized controlled trials reporting outcomes of HBCs compared with non-HBCs. Primary outcomes assessed were postoperative blood/blood-product transfusion and blood loss. Secondary outcomes included all-cause mortality, acute postoperative myocardial infarction, stroke, re-sternotomy for postoperative bleeding, wound infection, atrial fibrillation, duration of ventilation, intensive care unit (ICU) and hospital-length of stay (LOS). Random effects meta-analytical techniques were applied to identify differences in outcomes between the two groups. Quality of the included studies and heterogeneity were assessed. From an initial review of 762-published studies, 41-randomized trials fulfilled the inclusion criteria, leaving 3434-patients' data for analysis. HBCs significantly decreased the incidence of blood transfusion required (OR=0.8; 95% CI=0.6:0.9, P=0.004). It also significantly decreased re-sternotomy (OR=0.6; 95% CI=0.4:0.8, P=0.002), duration of ventilation (WMD= -1.3h; 95% CI= -1.9:-0.6, P<0.001), ICU-LOS (WMD= -9.3h; 95% CI=-14.7:-3.9, P<0.001) and hospital-LOS (WMD= -0.5 day; 95% CI= -0.9:-0.1, P=0.02). HBCs had no effect on other adverse events evaluated. Although HBCs showed a positive effect on some of the clinical outcomes, we identified only marginal differences for other outcomes. Further evaluation of the cost-effectiveness of this technology is required.