Comparison of Clinical Scoring Tools to Predict Heparin-Induced Thrombocytopenia in Cardiac Surgery.

The 4Ts and HIT-Expert Probability (HEP) scoring tools for heparin-induced thrombocytopenia (HIT) have not been validated in cardiac surgery patients, and the reported sensitivity and specificity of the Post-Cardiopulmonary Bypass (CPB) scoring tool vary widely in the 2 available analyses. It remains unclear which of the available scoring tools most accurately predicts HIT in this population. Forty-nine HIT-positive patients who underwent on-pump cardiac surgery within a 6-year period were loosely matched to 98 HIT-negative patients in a 1:2 case-control design. The 4Ts, HEP, and CPB scores were calculated for each patient. Sensitivity and specificity of each tool were calculated using standard cut-offs. The Youden method was utilized to determine optimal cut-offs within receiver operating characteristic (ROC) curves of each score, after which sensitivities and specificities were recalculated. Using standard cut-offs, the sensitivities for the CPB, HEP, and 4Ts scores were 100%, 93.9%, and 69.4%, respectively. Specificities were 51%, 49%, and 71.4%, respectively. The AUC of the scoring tool ROC curves were 0.961 for the CPB score, 0.773 for the HEP score, and 0.805 for the 4Ts score. Using the Youden method-derived optimal cut-off of  ≥3 points on the CPB score, sensitivity remained 100% with improved specificity to 88.9%. The CPB score is the preferred HIT clinical scoring tool in adult cardiac surgery patients, whereas the 4Ts score performed less effectively. A cut-off of ≥ 3 points on the CPB score could increase specificity while preserving high sensitivity, which should be validated in a prospective evaluation.

Continuous-infusion von Willebrand factor concentrate is effective for the management of acquired von Willebrand disease.

Acquired von Willebrand disease (aVWD) is a rare disorder associated with a reduction in von Willebrand factor (VWF) activity, leading to increased bleeding risk. Monoclonal gammopathy of undetermined significance (MGUS) is the most common cause of lymphoproliferative disorder-associated aVWD and is caused by accelerated clearance of circulating VWF. Standard VWF replacement protocols for congenital VWD based on intermittent bolus dosing are typically less effective for aVWD because of antibody-mediated clearance. Intermittent bolus dosing of VWF concentrates often leads to inadequate peak response and profoundly shortened VWF half-life in aVWD. Intravenous immune globulin (IVIG) has demonstrated efficacy in aVWD; however, treatment effect is delayed up to 4 days, limiting its efficacy in acutely bleeding patients. We report the successful use of continuous-infusion VWF concentrate (with or without concomitant IVIG) in 3 patients with MGUS-associated aVWD who had demonstrated an inadequate response to bolus dosing. VWF concentrate doses required in this cohort were higher than typical doses for bleeding treatment in congenital VWD. This report illustrates that continuous-infusion VWF concentrate administration with or without intravenous immunoglobulin rapidly achieves target ristocetin cofactor activity and provides adequate hemostasis in aVWD associated with immunoglobulin G MGUS.

Successful use of emicizumab in a patient with refractory acquired hemophilia A and acute coronary syndrome requiring percutaneous coronary intervention.

ABSTRACT: We report a patient with a high-titer factor VIII inhibitor refractory to immunosuppression. He initially presented with myocardial infarction requiring percutaneous coronary intervention (PCI) with bare metal stent placement. Despite Feiba prophylaxis, inadequate hemostasis prompted premature discontinuation of dual antiplatelet therapy (DAPT). Fifteen weeks later, the patient presented with a left anterior descending artery in-stent restenosis. This case report examines the Key Clinical Question of how to manage in-stent restenosis in a patient with acquired hemophilia A (AHA). After multidisciplinary discussions including hematology, cardiology, cardiac surgery, laboratory medicine, and pharmacy, emicizumab was initiated to facilitate PCI. Four weeks after emicizumab initiation, the patient underwent successful PCI with drug-eluting stent placement. Five months after discharge, he remains without signs or symptoms of cardiac disease or bleeding on DAPT and emicizumab. This case provides evidence of the potential of emicizumab for bleeding prophylaxis in AHA.

Safety of novel oral anticoagulants compared with uninterrupted warfarin for catheter ablation of atrial fibrillation.

BACKGROUND: The novel oral anticoagulants (NOACs) are used for stroke prevention in atrial fibrillation (AF), but their safety and efficacy in the periablation period are not well established. Additionally, no standard procedure for managing periprocedural and intraprocedural anticoagulation has been established. OBJECTIVE: To evaluate the frequency of hemorrhagic and thrombotic events as well as periprocedural management strategies of NOACs compared with warfarin as anticoagulation therapy for AF ablation. METHODS: This was a retrospective cohort study from a prospective AF ablation registry maintained at a large, academic medical center. RESULTS: A total of 374 cases (173 warfarin, 123 dabigatran, 61 rivaroxaban, and 17 apixaban) were included in the analysis. The overall hemorrhagic/thrombotic event rate was 14.2 % (major hemorrhage 2.7%, minor hemorrhage 11.2%, thrombotic stroke 0.5%). The frequency of minor hemorrhage was significantly higher with warfarin compared with dabigatran (15% vs 5.7%, P = 0.012). The average heparin dose required to reach the goal activated clotting time (ACT) was 5600 units for warfarin, 12 900 units for dabigatran (P < 0.001), 15 100 units for rivaroxaban (P < 0.001), and 14 700 units for apixaban (P < 0.001). The average time in minutes to reach the goal ACT was significantly longer, compared with warfarin, for dabigatran (57 vs 28, P < 0.001), rivaroxaban (63 vs 28, P < 0.001), and apixaban (72 vs 28, P < 0.001). CONCLUSIONS: Compared with warfarin, periprocedural anticoagulation with dabigatran resulted in fewer minor hemorrhages and total adverse events after AF ablation. Patients anticoagulated with NOACs required larger doses of heparin and took longer to reach the goal ACT compared with patients anticoagulated with warfarin.