Low molecular weight heparin in COVID-19: benefits and concerns

Since its emergence, the COVID-19 pandemic had a dramatic impact on the public health worldwide and it scarred the medical, economical, and social determinants of health. Even after the significant vaccination advances, the disease of SARS-CoV-2 can manifest in severe presentations with life-threatening thromboembolic and multi-organ complications leading to notable morbidity and mortality. Clinicians and researchers are on continuous pursuit of investigating different approaches in the attempt to prevent the infection and minimize its severity. Although the COVID-19's pathophysiology remains relatively unclear, it is well established now that coagulopathy, systemic thrombotic propensity, and a robust immunoinflammatory response are some of the most important determinants of its morbidity and mortality. Accordingly, research efforts have focused on addressing the inflammatory and hematological cascades using available agents to avoid thromboembolic events. Several studies and investigators have emphasized the importance of Low molecular weight heparin (LMWH), namely, Lovenox, in addressing these sequelae of the COVID-19 disease, either prophylactically or therapeutically. This review explores the benefits and concerns of employing LMWH, a widely used anticoagulant, in COVID-19 disease. It delves into Enoxaparin as a molecule, along with its pharmacology, mechanism of action, and clinical uses. It also reviews the current high-quality clinical evidence that highlight the role of enoxaparin in SARS-CoV-2 infection.

A Retrospective Comparative Cohort Study of Craniotomy and Prophylactic Enoxaparin Timing

INTRODUCTION

 Post-operative venous thromboembolism (VTE) prophylaxis is the standard of care after craniotomy, but there is debate over when to initiate VTE prophylaxis to decrease the morbidity and mortality experienced by these patients. This study aims to determine the effects of starting enoxaparin on day one vs. day three after craniotomy.

METHODS

We used a multi-institutional health research network (TriNetX) to gather data from the electronic medical records of patients who started enoxaparin one day after craniotomy (cohort 1) and patients who started it three days later (cohort 2). Our primary endpoint was mortality, with the secondary endpoints of deep venous thrombosis (DVT), additional craniotomy, pulmonary embolism (PE), myocardial infarction (MI), ischemic stroke (IS), intracerebral hemorrhage (ICH), ventilator and tracheostomy dependence, or percutaneous endoscopic gastrostomy (PEG) tube dependence. Patients were propensity score-matched for demographics, common comorbidities, and anticoagulant and antiplatelet use.

RESULTS

After propensity score matching, 1,554 patients were identified in each cohort. In cohort 1, 21.171% of patients were deceased after five years vs. 26.126% in cohort 2 (p= 0.0012; OR 0.759, 95% CI (0.643,0.897)). The 30-day survival was 94.521% vs. 93.049%, the 90-day survival was 90.200% vs. 87.335%, and the 365-day survival was 80.619 vs. 76.817%. Deep venous thrombosis occurred in 5.277% of cohort 1 and 7.851% of cohort 2 (p=0.0038, OR 0.654, 95% CI [0.49,0.873]). There was no increase in intracerebral hemorrhage in cohort 1. There were no statistically significant differences in subsequent craniotomy rates, PE, MI, IS, ventilator/tracheostomy, or PEG tube dependence.

CONCLUSION

Starting enoxaparin on day one after craniotomy was associated with decreased mortality and DVTs, with no difference in rates of PE, MI, IS, tracheostomy/PEG dependence, or further craniotomy.

Comparative Studies on the Anticoagulant Profile of Branded Enoxaparin and a New Biosimilar Version

Low molecular weight heparins (LMWH) represent depolymerized heparin prepared by various methods that exhibit differential, biochemical and pharmacological profiles. Enoxaparin is prepared by benzylation followed by alkaline depolymerization of porcine heparin. Upon the expiration of its patent, several biosimilar versions of enoxaparin have become available. Heparinox (Sodic enoxaparine; Cristália Produtos Químicos Farmacêuticos LTDA, Sao Paulo, Brazil) is a new biosimilar form of enoxaparin. We assessed the molecular weight and the biochemical profile of Heparinox and compared its properties to the original branded enoxaparin (Lovenox; Sanofi, Paris, France). Clotting profiles compared included activated clotting time, activated partial thromboplastin time (aPTT), and thrombin time (TT). Anti-protease assays included anti-factor Xa and anti-factor IIa activities. Thrombin generation was measured using a calibrated automated thrombogram and thrombokinetic profile included peak thrombin, lag time and area under the curve. USP potency was determined using commercially available assay kits. Molecular weight profiling was determined using high performance liquid chromatography. We determined that Heparinox and Lovenox were comparable in their molecular weight profile. Th anticoagulant profile of the branded and biosimilar version were also similar in the clot based aPTT and TT. Similarly, the anti-Xa and anti-IIa activities were comparable in the products. No differences were noted in the thrombin generation inhibitory profile of the branded and biosimilar versions of enoxaparin. Our studies suggest that Heparinox is bioequivalent to the original branded enoxaparin based upon in vitro tests however will require further in vivo studies in animal models and humans to determine their clinical bioequivalence.