A journey through anticoagulant therapies in the treatment of left ventricular thrombus in post-COVID-19 heparin-induced thrombocytopenia: a case report.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is an immune-mediated adverse drug reaction associated with thrombosis. Clinical scoring systems and the presence of anti-platelet factor 4 (anti-PF4)/heparin antibodies determine the diagnosis. CASE PRESENTATION: A 57-year-old man who was treated with acenocoumarol due to a chronic left ventricular thrombus was admitted to the hospital for severe SARS-CoV-2 pneumonia and pulmonary embolism. The patient was started on bemiparin and discharged. Left lower limb acute arterial ischemia and thrombocytopenia were diagnosed 18 days later. Computed tomography angiography revealed a large left ventricular thrombus and multiple arterial thrombi. Left femoral-popliteal thromboembolectomy was performed. Anti-PF4/heparin antibodies confirmed an HIT diagnosis. Fondaparinux (7.5 mg/24 h) was initiated, but cardiac surgery was necessary. Bivalirudin was used during surgery, with an initial load (1.25 mg/kg) and maintenance infusion (2.5 mg/kg/h). The cardiac thrombus was extracted, but the patient experienced a postsurgical myocardial infarction. Percutaneous cardiovascular intervention (PCI) required a bivalirudin load (0.75 mg/kg) and maintenance infusion (1.75 mg/kg/h). No coronary lesions were detected, and argatroban was started afterwards (0.5 µg/kg/min). When the platelet count exceeded 100 × 109/L, acenocoumarol was initiated. Thereupon, acetylsalicylic acid (100 mg/24 h) was added. No other complications have been reported to date. CONCLUSION: The clinical presentation of intraventricular and multiple arterial thrombi is remarkable. SARS-CoV-2 infection likely contributed to a hypercoagulable state. The management of patients with HIT undergoing cardiac surgery is challenging. If surgery cannot be delayed, then treatment with bivalirudin is recommended. Additionally, this drug is recommended for PCI. Bivalirudin is safe and well-tolerated in both procedures.

Comparison of different anticoagulation strategies for renal replacement therapy in critically ill patients with COVID-19: a cohort study.

BACKGROUND: Critically ill coronavirus disease 2019 (COVID-19) patients have a high risk of acute kidney injury (AKI) that requires renal replacement therapy (RRT). A state of hypercoagulability reduces circuit life spans. To maintain circuit patency and therapeutic efficiency, an optimized anticoagulation strategy is needed. This study investigates whether alternative anticoagulation strategies for RRT during COVID-19 are superior to administration of unfractionated heparin (UFH). METHODS: Retrospective cohort study on 71 critically ill COVID-19 patients (≥18 years), admitted to intensive care units at a tertiary health care facility in the southwestern part of Germany between February 26 and May 21, 2020. We collected data on the disease course, AKI, RRT, and thromboembolic events. Four different anticoagulatory regimens were administered. Anticoagulation during continuous veno-venous hemodialysis (CVVHD) was performed with UFH or citrate. Anticoagulation during sustained low-efficiency daily dialysis (SLEDD) was performed with UFH, argatroban, or low molecular weight heparin (LMWH). Primary outcome is the effect of the anticoagulation regimen on mean treatment times of RRT. RESULTS: In patients receiving CVVHD, mean treatment time in the UFH group was 21.3 h (SEM: ±5.6 h), in the citrate group 45.6 h (SEM: ±2.7 h). Citrate anticoagulation significantly prolonged treatment times by 24.4 h (P = .001). In patients receiving SLEDD, mean treatment time with UFH was 8.1 h (SEM: ±1.3 h), with argatroban 8.0 h (SEM: ±0.9 h), and with LMWH 11.8 h (SEM: ±0.5 h). LMWH significantly prolonged treatment times by 3.7 h (P = .008) and 3.8 h (P = .002), respectively. CONCLUSIONS: UFH fails to prevent early clotting events in the dialysis circuit during COVID-19. For patients, who do not require effective systemic anticoagulation, regional citrate dialysis is the most effective strategy. For patients, who require effective systemic anticoagulation, the usage of LMWH results in the longest circuit life spans. The proposed anticoagulatory strategies are safe, can easily be monitored, and allow an individualized treatment.