Anticoagulation During Extracorporeal Membrane Oxygenation; Nafamostat Mesilate Versus Heparin

Background. Heparin is the main anticoagulant used during extracorporeal membrane oxygenation (ECMO) support. Nafamostat mesilate, a synthetic serine protease inhibitor, has seen increased use as a substitute for heparin in patients undergoing ECMO because of its short half-life. We aimed to compare these 2 anticoagulants with respect to bleeding and thromboembolic complications during ECMO support. Methods. From January 2005 to November 2014, 320 patients who underwent venoarterial ECMO support were retrospectively reviewed. The primary end point was thromboembolic or bleeding complications during ECMO support. Propensity score matching was used to compare the 2 groups. Univariate and multivariate analyses were performed for risk factor analysis. Results. The mean duration of support was 111 +/- 101 hours in all the study participants. Among them, ECMO was weaned successfully in 59 (48.4%) patients. Heparin was used in 201 patients, whereas nafamostat was used in 119 patients. Bleeding complications were significantly higher in the nafamostat group in both the unmatched and matched cohorts (p = 0.03), whereas thromboembolic events were comparable. Regarding risk factor analysis, nafamostat use was the only significant risk factor for bleeding (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.07-5.36; p = 0.032), whereas only old age was a risk factor for thromboembolic complications (HR, 1.06; 95% CI, 1.01-1.11; p = 0.03) regardless of the type of anticoagulant used. Conclusions. Nafamostat mesilate was found to increase the bleeding risk in patients receiving venoarterial ECMO. Regarding thromboembolic complications, there was no significant difference between heparin and nafamostat. Only old age increased the thromboembolic risk. (C) 2016 by The Society of Thoracic Surgeons