COVID-19, thromboembolic risk and thromboprophylaxis: learning lessons from the bedside, awaiting evidence

Role of LL-37 in thrombotic complications in patients with COVID-19

Blood clot formation induced by dysfunctional coagulation is a frequent complication of coronavirus disease 2019 (COVID-19) and a high-risk factor for severe illness and death. Neutrophil extracellular traps (NETs) are implicated in COVID-19-induced immunothrombosis. Furthermore, human cathelicidin, a NET component, can perturb the interaction between the SARS-CoV-2 spike protein and its ACE2 receptor, which mediates viral entry into cells. At present, however, the levels of cathelicidin antimicrobial peptides after SARS-CoV-2 infection and their role in COVID-19 thrombosis formation remain unclear. In the current study, we analyzed coagulation function and found a decrease in thrombin time but an increase in fibrinogen level, prothrombin time, and activated partial thromboplastin time in COVID-19 patients. In addition, the cathelicidin antimicrobial peptide LL-37 was upregulated by the spike protein and significantly elevated in the plasma of patients. Furthermore, LL-37 levels were negatively correlated with thrombin time but positively correlated with fibrinogen level. In addition to platelet activation, cathelicidin peptides enhanced the activity of coagulation factors, such as factor Xa (FXa) and thrombin, which may induce hypercoagulation in diseases with high cathelicidin peptide levels. Injection of cathelicidin peptides promoted the formation of thrombosis, whereas deletion of cathelicidin inhibited thrombosis in vivo. These results suggest that cathelicidin antimicrobial peptide LL-37 is elevated during SARS-CoV-2 infection, which may induce hypercoagulation in COVID-19 patients by activating coagulation factors.

Protecting older patients with cardiovascular diseases from COVID-19 complications using current medications

PURPOSE

In the pathogenesis of severe COVID-19 complications, derangements of renin-angiotensin-aldosterone system (RAAS), vascular endothelial dysfunction leading to inflammation and coagulopathy, and arrhythmias play an important role. Therefore, it is worth considering the use of currently available drugs to protect COVID-19 patients with cardiovascular diseases.

METHODS

We review the current experience of conventional cardiovascular drugs [angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers, anticoagulants, acetosalicylic acid, antiarrhythmic drugs, statins] as well as some other drug classes (antidiabetic drugs, vitamin D and NSAIDs) frequently used by older patients with cardiovascular diseases. Data were sought from clinical databases for COVID-19 and appropriate key words. Conclusions and recommendations are based on a consensus among all authors.

RESULTS

Several cardiovascular drugs have a potential to protect patients with COVID-19, although evidence is largely based on retrospective, observational studies. Despite propensity score adjustments used in many analyses observational studies are not equivalent to randomised controlled trials (RCTs). Ongoing RCTs include treatment with antithrombotics, pulmonary vasodilators, RAAS-related drugs, and colchicine. RCTs in the acute phase of COVID-19 may not, however, recognise the benefits of long term anti-atherogenic therapies, such as statins.

CONCLUSIONS

Most current cardiovascular drugs can be safely continued during COVID-19. Some drug classes may even be protective. Age-specific data are scarce, though, and conditions which are common in older patients (frailty, comorbidities, polypharmacy) must be individually considered for each drug group.

Experimental Pharmacotherapy for COVID-19: The Latest Advances

The coronavirus infectious disease-2019 (COVID-19) has overwhelmed like a shock wave in a completely unprepared world. Despite coronavirus infections were involved in previous epidemic outbreaks, no antiviral agent was developed for specific treatment. As a consequence, since the beginning of this pandemic, both repositioned and experimental drugs were used to treat the infected patients without evidence of clinical efficacy. Just based on experience coming from the use of antiviral agents to treat other viruses (eg, lopinavir/ritonavir, remdesivir) and supposed antiviral or immunomodulatory activities of drugs with no approved antiviral indications (eg hydroxychloroquine, tocilizumab), clinicians have faced the ongoing pandemic. Currently, after about 9 months from the COVID-19 spread, there is still no antiviral agent capable of ensuring the cure of this syndrome. Clinical trials are beginning to confirm the benefits of some drugs, while for other compounds, efficacy and safety have not yet been confirmed. Randomized clinical trials (RCT) have denied or downsized the beneficial effects attributed to certain molecules, such as aminoquinolines, largely used in clinical practice at the beginning of COVID-19 spread. Conversely, at the same time, they have provided evidence for unexpected effectiveness of other agents that have been underutilized, such as steroids, which were not used in SARS treatment because of the threatened effect on viral replication. Evidence deriving from pathologic studies have demonstrated that the prothrombotic effects of SARS-CoV-2 can be prevented by heparin prophylaxis, underlining the need for personalized treatment for patients with severe disease. The main aim of this review is to synthesize the available information and evidence on both repositioned and experimental drugs for the treatment of COVID-19, focusing on the need to exercise caution on the use of unproven medical therapies.

Update on therapeutic approaches and emerging therapies for SARS-CoV-2 virus

The global pandemic of coronavirus disease 2019 (COVID-19), caused by novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in over 7,273,958 cases with almost over 413,372 deaths worldwide as per the WHO situational report 143 on COVID-19. There are no known treatment regimens with proven efficacy and vaccines thus far, posing an unprecedented challenge to identify effective drugs and vaccines for prevention and treatment. The urgency for its prevention and cure has resulted in an increased number of proposed treatment options. The high rate and volume of emerging clinical trials on therapies for COVID-19 need to be compared and evaluated to provide scientific evidence for effective medical options. Other emerging non-conventional drug discovery techniques such as bioinformatics and cheminformatics, structure-based drug design, network-based methods for prediction of drug-target interactions, artificial intelligence (AI) and machine learning (ML) and phage technique could provide alternative routes to discovering potent Anti-SARS-CoV2 drugs. While drugs are being repurposed and discovered for COVID-19, novel drug delivery systems will be paramount for efficient delivery and avoidance of possible drug resistance. This review describes the proposed drug targets for therapy, and outcomes of clinical trials that have been reported. It also identifies the adopted treatment modalities that are showing promise, and those that have failed as drug candidates. It further highlights various emerging therapies and future strategies for the treatment of COVID-19 and delivery of Anti-SARS-CoV2 drugs.

Fracture management during COVID-19 pandemic: A systematic review

PURPOSE

The COVID-19 pandemic has affected orthopedic practices worldwide. Few studies focusing on epidemiology and management of fractures in COVID-19 patients have been published. We conducted a systematic review to evaluate the fracture types, presentation, treatment, complications, and early outcomes of fractures occurring amidst COVID-19 pandemic.

METHODS

A systematic review of the all published papers was conducted with a comprehensive search of PubMed, Google Scholar, Scopus, and Cochrane Library database using keywords 'COVID-19', 'Coronavirus', 'trauma∗'and 'fracture' from January-April 2020.

RESULTS

The searches yielded a total of ten studies with 112 Patients who were positive for COVID-19 associated with fractures was performed for six studies, reporting data separately for 44 patients with COVID 19 and an associated fracture. A diagnosis of COVID 19 was made on the basis of positive Computed Tomography scan in 39 patients and 30 patients had a positive Reverse Transcription-Polymerase Chain Reaction test. Overall, there were 29 proximal femoral fractures, 8 spine fractures, 7 fractures of the other bones. The fractures were treated surgically in 30 cases (68.18%) and the remaining 14 cases (31.82%) were managed conservatively. There were 16 patients (36.36%) who died, mostly due to respiratory failure with a median age of 82 years.

CONCLUSION

COVID-19 has led to a significant reduction in a load of fracture patients globally, though the incidence of fragility fractures continues to be unaffected. There is a significantly higher risk of mortality in elderly patients with fractures and hence they should only be operated in a facility with a robust intensive care. Conservative treatment should be adopted as far as possible in non-obligatory fractures and in lesser equipped centers. Surgery in patients with proximal femur fragility fractures when judiciously selected did result in improvement in respiratory status. Reorganizing medical services is vital to deliver effective fracture care and also mitigate disease transmission.