Antithrombotic therapy management of adult and pediatric cardiac surgery patients.

Despite the development of catheter-based interventions for ischemic and valvular heart disease, hundreds of thousands of people undergo open heart surgery annually for coronary artery bypass graft (CABG), valve replacement or cardiac assist device implantation. Cardiac surgery patients are unique because therapeutic anticoagulation is required during cardiopulmonary bypass. Developmental hemostasis and altered drug metabolism affect management in children. This narrative review summarizes the current evidence-based and consensus guidelines regarding perioperative, intraoperative and postoperative antithrombotic therapy in patients undergoing cardiac surgery. Anticoagulation preoperatively is required in the setting of cardiac arrhythmias, prior valve replacement or history of venous thromboembolism. In patients with ischemic heart disease, aspirin is continued in the perioperative period, whereas oral P2Y12 antagonists are withheld for 5-7 days to reduce the risk of perioperative bleeding. Intraoperative management of cardiopulmonary bypass in adults and children includes anticoagulation with unfractionated heparin. Variability in dose-response to heparin and influence of other medical conditions on dosing and reversal of heparin make intraoperative anticoagulation challenging. Vitamin K antagonist therapy is the standard anticoagulant after mechanical heart valve or left ventricular assist device (LVAD) implantation. Longer duration of dual antiplatelet therapy is recommended after CABG if patients undergo surgery because of acute coronary syndrome. Antiplatelet therapy after LVAD implantation includes aspirin, dipyridamole and/or clopidogrel in children and aspirin in adults. A coordinated approach between hematology, cardiology, anesthesiology, critical care and cardiothoracic surgery can assist to balance the risk of thrombosis and bleeding in patients undergoing cardiac surgery.

Antithrombotic therapy for left ventricular assist devices in adults: a systematic review.

BACKGROUND: Left ventricular assist devices (LVADs) have dramatically increased the survival of adults with end-stage systolic heart failure. However, rates of bleeding and thromboembolism remain high. OBJECTIVES: We completed a systematic review to evaluate outcomes of adults with LVADs treated with various anticoagulant and antiplatelet strategies. METHODS: Databases were searched using the terms 'assist device', 'thrombosis', and 'anticoagulant' or 'platelet aggregation inhibitor' with appropriate synonyms, device names and manufacturers. RESULTS AND CONCLUSIONS: Of 977 manuscripts, 24 articles met the inclusion criteria of adults with implanted LVADs where clinical outcomes were defined based on anticoagulant and/or antiplatelet regimen. Most studies reported treatment with unfractionated heparin post-operatively which was transitioned to a vitamin K antagonist (VKA). Goal INR varied between 1.5-3.5. Antiplatelet regimens ranged from no treatment to dual therapy. Definition of major bleeding differed between trials and incidence varied between 0% and 58%. The available evidence could not demonstrate a clear benefit of aspirin compared with VKA therapy alone [stroke RR 1.02 (95% CI 0.49-2.1)]. There was a suggestion that treatment with aspirin and dipyridamole decreased the risk of thromboembolism compared to aspirin [RR 0.50 (0.36-0.68)], but the comparison is limited by differences in demographics, devices, and INR goals among studies. Additionally, most studies did not blind investigators to outcomes thus contributing to an increased risk for bias. Clinical equipoise exists as to the most appropriate antithrombotic therapy in LVAD patients. Randomization between regimens within a prospective trial is needed to define the treatment regimen that minimizes both bleeding and thrombotic complications.

Not only in trauma patients: hospital-wide implementation of a massive transfusion protocol.

OBJECTIVES: To review outcomes of massive transfusion protocol (MTP) activation and determine the impact of MTP implementation on blood bank use. BACKGROUND: MTP has been established to rapidly provide plasma and packed red blood cells in ratios approaching 1 : 1. Due to availability, MTP has been utilised in non-traumatic haemorrhage despite evidence of benefit in this population. Our hospital-wide implementation of MTP was reviewed for propriety, outcomes and effect on blood bank resources. METHODS: Retrospective cohort study of patients receiving transfusion after MTP activation from October 2009 to 2011. Underlying medical conditions and baseline medication use were determined. In-hospital and 24-h mortality were compared with evaluation for confounding by Acute Physiology And Chronic Health Evaluation (APACHE) score and duration of MTP activation. Blood product use before and after MTP implementation was reviewed. RESULTS: MTP activation occurred in 62 trauma and 63 non-trauma patients. Non-trauma patients were older, had more underlying medical conditions and higher APACHE scores compared with trauma patients; 24-h mortality was higher in trauma compared with non-trauma patients (27·4 vs 11·1%, P = 0·02). There was no significant difference of in-hospital mortality. Transfusion ratio did not differ between trauma and non-trauma patients and was not associated with mortality even when MTP activation duration and APACHE score were considered. Hospital-wide blood product use did not change with MTP implementation. CONCLUSIONS: MTP may be successfully used in trauma and non-trauma settings without significantly impacting overall blood product utilisation. Inclusion of non-trauma patients into prospective studies of resuscitation with blood products is warranted to ensure benefit in these patients.

Is prophylaxis required for delivery in women with factor VII deficiency?

Factor VII (fVII) deficiency is a rare congenital bleeding disorder in which fVII activity level and bleeding tendency do not completely correlate. Pregnancy and delivery present a significant haemostatic challenge to women with fVII deficiency. Treatment with recombinant factor VIIa (rfVIIa) carries a thrombotic risk and the literature is not clear whether prophylaxis is necessary prior to delivery. The aim of this study was to define management, haemorrhagic and thrombotic complications of pregnant women with fVII deficiency through a systematic review. Medical databases (PubMed, MEDLINE, CINAHL, Academic Search Premier, Cochrane Library, Web of Science and Scopus) were searched using "factor VII deficiency" and "pregnancy" or "surgery." Overall 34 articles, four abstracts, and three institutional cases were reviewed. Literature from 1953 to 2011 reported 94 live births from 62 women with fVII deficiency. The median fVII activity was 5.5%. Haemostatic prophylaxis was used in 32% of deliveries. Without prophylaxis, 40 vaginal deliveries and 16 caesarean sections were completed. The odds of receiving prophylaxis were 2.9 times higher in women undergoing caesarean section compared to vaginal delivery. Post-partum haemorrhage occurred in 10% of deliveries with prophylaxis and 13% of deliveries without prophylaxis. The fVII level did not significantly differ between women who did and did not receive prophylaxis. We present the only systematic review of the management of pregnancy in fVII deficient women. No difference in post-partum haemorrhage was seen in deliveries with and without prophylaxis. Therefore, we recommend that rfVIIa be available in the case of haemorrhage or surgical intervention, but not as mandatory prophylaxis.