Circulatory assist devices are applied to support patients with end-stage heart failure or circulatory collapse. Extracorporeal membrane oxygenation (ECMO) and ventricular assist device (VAD) are the two devices that are commonly used in these situations. However, in patients undergoing ECMO, complications occur more frequently and are more severe than in those with VAD, especially in patients with coagulopathy. The cause of coagulopathy is seldom reported; therefore, the current prospective study was designed to compare the coagulation status between patients who received ECMO and bridged VAD thereafter.
The cases for our study were collected between December 2005 and January 2010. A total of 21 patients with VAD were enrolled. Seven patients received initial ECMO support and were subsequently shifted to VAD. Use of blood transfusion products by patients was recorded during application of ECMO and VAD. Thrombelastography (TEG) was performed pre-ECMO and pre-VAD, and thereafter to 1 week post-VAD implantation. The relevant parameters that were examined included coagulation time (R: resting, K: kinetics, seconds), angle (α, degrees), maximal amplitude (MA, mm), clot strength (G, dynes/cm(2)), and estimated percent lysis in 30 minutes (LY30, %). Coagulation status and average unit per day of bloodtransfusion at pre-VAD and post-VAD status were recorded. TEGs of pre-VAD and post-VAD implantation were compared in order to determine the frequency of bleeding.
Average results from seven cases were incorporated into the current analysis. The patient transfusion requirement was reduced after implantation of the VAD. The TEG of post-VAD implantation was improved from the earlier pre-VAD results (ECMO status). Ultimately, TEG resulted in significant differences in R, K, angle, MA, and G, postoperatively.
Coagulopathy of patients with VAD improved after bridging from ECMO, which can be attributed to improved coagulation factor and platelet function. Thus, bleeding complications are reduced.