Bleeding management with fibrinogen concentrate targeting a high-normal plasma fibrinogen level: a pilot study

TLDR: In this article, the authors evaluated the haemostatic efficacy of fibrinogen concentrate in correcting acquired perioperative deficiency in complex cardiac surgery using FIBTEM.

Abstract: Complex cardiac surgery is frequently accompanied by excessive perioperative bleeding because of coagulation system impairment, inadequate surgical haemostasis, or both.1 Bleeding increases the risk of re-exploration, allogeneic blood transfusion, or perioperative myocardial infarction, and consequently, associated morbidity and mortality.2 Aortic valve operation and ascending aorta replacement (AV–AA) typically involves hypothermia, prolonged cardiopulmonary bypass (CPB), and large graft anastomoses, and is associated with an increased risk of intra- and postoperative blood loss and high transfusion rates.3,4 Conventional haemostatic therapy consists of transfusion of allogeneic blood products that include fresh-frozen plasma (FFP), platelet concentrate, and cryoprecipitate. However, although the use of these products was developed empirically, their haemostatic efficacy has not been evaluated thoroughly in the surgical setting.5,6 Haemocomplettan® P (brand name in Europe)/Riastap (brand name in USA) (CSL Behring, Marburg, Germany) is a highly purified, lyophilized, virus-inactivated fibrinogen concentrate obtained from human plasma that can be rapidly reconstituted without the need for thawing and cross-matching, which are necessary for FFP and cryoprecipitate. The administration of fibrinogen concentrate was originally reserved for replacement therapy in congenital fibrinogen deficiency, and in the USA, Riastap is only approved for this indication. In the meantime, European reports on haemostatic therapy with Haemocomplettan® P in acquired perioperative deficiency of fibrinogen have been published.7–11 Acquired fibrinogen deficiency occurring during and after CPB is associated with increased bleeding after cardiac surgery.12,13 However, the haemostatic efficacy of fibrinogen concentrate in correcting such deficiency in complex cardiac surgery has not been investigated to date. To reduce blood component transfusion in cardiac surgery, point-of-care methods such as thrombelastography/thromboelastometry have been applied in algorithms supporting bleeding management in relation to blood clotting quality.14–16 Thromboelastometry (ROTEM®; Pentapharm GmbH, Munich, Germany) assesses the viscoelasticity of whole blood. One of the ROTEM® tests, the FIBTEM test, provides prompt information on the clot strength specifically attributed to fibrin/fibrinogen using cytochalasin-D-induced inactivation of platelets in vitro.17 This test may be used to guide the administration of fibrinogen concentrate for prompt haemostatic therapy.9–11 We hypothesized that postoperative haemostasis could be improved by increasing plasma fibrinogen concentrations, since bleeding complications were observed to be lower in patients with high perioperative fibrinogen concentrations.12,13 The primary aim of this pilot study was to evaluate whether FIBTEM-guided intraoperative fibrinogen repletion was able to reduce the use of allogeneic blood products and postoperative bleeding in patients undergoing AV–AA.