The Efficacy and Safety of Enoxaparin: A Meta-analysis

Current Status and Future Direction of Antithrombotic Therapy for Patients with STEMI Undergoing Primary PCI

Since the introduction of the first pharmacological therapy for the treatment of patients with acute myocardial infarction in the early 20th century, treatment of myocardial infarction has evolved extensively throughout the years. Mechanical revascularization therapies such as the percutaneous transluminal coronary angioplasty, combined with the ongoing development of pharmacological therapies have successfully improved the survival of patients with acute myocardial infarction. To date, antiplatelet therapy (consisting of aspirin and an oral P2Y 12 inhibitor) and anticoagulation therapy represent the main stay of pharmacological treatment in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). The routine use of clopidogrel as antiplatelet agent has been largely replaced by the use of the more potent P2Y 12 inhibitors ticagrelor and prasugrel. Unfractionated heparin remains the preferred anticoagulant therapy, despite the development of other anticoagulants, including enoxaparin and bivalirudin. To date, limited evidence exists supporting a pre-hospital initiation of antiplatelet and anticoagulant therapy in STEMI patients. The use of potent intravenous antiplatelet agents, including the glycoprotein IIb/IIIa inhibitors and the intravenous P2Y 12 inhibitor cangrelor, is currently restricted to specific clinical settings. While several potent antithrombotic agents already exist, the search for novel potent antithrombotic agents continues, with a focus on balancing antithrombotic properties with an improved safety profile to reduce excess bleeding. This review provides an overview of currently available pharmacological therapies for the treatment of STEMI patients undergoing primary PCI, and an outlook for the ongoing development of novel agents in this field.

Evaluation of Unfractionated Heparin Dosing by Antifactor Xa During Targeted Temperature Management Post Cardiac Arrest

Purpose

To evaluate unfractionated heparin (UFH) dosing guided by antifactor Xa levels during targeted temperature management (TTM) post-cardiac arrest.

Methods

Single-center, retrospective, observational study between January 1, 2014 and September 1, 2020. Patients initiated on TTM post-cardiac arrest and UFH were evaluated for inclusion. Patients included were ≥18 years of age and received weight-based UFH for ≥6 hours with 2 antifactor Xa levels drawn at target temperature. Excluded patients had no available temperature readings, received extracorporeal membrane oxygenation (ECMO) or factor Xa inhibitor (within 72 hours), or had hypertriglyceridemia or hyperbilirubinemia. The primary endpoint was to evaluate the proportion of patients that achieved a therapeutic antifactor Xa level between 0.3 and 0.7 IU/mL at steady state during TTM. Secondary endpoints included average UFH dose and average time to therapeutic antifactor Xa level at steady state; percent of first and total antifactor Xa levels subtherapeutic, therapeutic, and supratherapeutic during TTM.

Results

A total of 73 patients met inclusion criteria. Of these, 21 patients achieved steady-state therapeutic antifactor Xa levels during TTM. The average time and dose to steady-state therapeutic antifactor Xa levels were 8.1 ± 4.5 hours and 9.9 ± 3.2 units/kg/hour. Overall, 61.7% of first and 47.4% of all antifactor Xa levels were supratherapeutic during TTM. Three (4.1%) patients experienced a major bleeding event.

Conclusions

Guideline recommended UFH dosing, 12 or 18 units/kg/hour, during TTM resulted in more supratherapeutic antifactor Xa levels. Reduction of UFH infusion dose to 10 units/kg/hour may be required during TTM to maintain therapeutic antifactor Xa levels.