The Cross-Talk between Thrombosis and Inflammatory Storm in Acute and Long-COVID-19: Therapeutic Targets and Clinical Cases

Safety and efficacy of favipiravir in COVID-19 patients with pneumonia. A randomized, double-blind, placebo-controlled study (FAVID)

PURPOSE

To design a randomized clinical trial to assess the efficacy and safety of favipiravir in patients with COVID-19 disease with pneumonia.

METHODS

A randomized, double blind, placebo-controlled clinical trial of favipiravir in patients with COVID-19 pneumonia was conducted in three Spanish sites. Randomization 1:1 to favipiravir or placebo (in both groups added to the Standard of Care) was performed to treat the patients with COVID-19 pneumonia. The primary endpoint was "time to clinical improvement," measured as an improvement for ≥ two categories on a 7-point WHO ordinal scale in an up to 28 days' time frame.

RESULTS

Forty-four patients were randomized (23 in the favipiravir group and 21 in the placebo group). The median time to clinical improvement was not different between the favipiravir and the placebo arms (10 days for both groups) and none of the secondary endpoints showed significant differences between arms. The proportion of adverse events (both serious and non-serious) was statistically different between the favipiravir group (68.29%) and the placebo group (31.7%) (p = 0.019), but there was insufficient statistical evidence to correlate the degree of severity of the events with the treatment group.

CONCLUSIONS

Favipiravir administered for ten days to patients with COVID-19 and pneumonia did not improve outcomes compared with placebo. Although this is an underpowered negative study, efficacy results align with other randomized trials. However, in the present study, the non-serious adverse events were more frequent in the favipiravir group.

Traumatic Brain Injury in the Long-COVID Era

Major determinants of the biological background or reserve, such as age, biological sex, comorbidities (diabetes, hypertension, obesity, etc.), and medications (e.g., anticoagulants), are known to affect outcome after traumatic brain injury (TBI). With the unparalleled data richness of coronavirus disease 2019 (COVID-19; ∼375,000 and counting!) as well as the chronic form, long-COVID, also called post-acute sequelae SARS-CoV-2 infection (PASC), publications (∼30,000 and counting) covering virtually every aspect of the diseases, pathomechanisms, biomarkers, disease phases, symptomatology, etc., have provided a unique opportunity to better understand and appreciate the holistic nature of diseases, interconnectivity between organ systems, and importance of biological background in modifying disease trajectories and affecting outcomes. Such a holistic approach is badly needed to better understand TBI-induced conditions in their totality. Here, I briefly review what is known about long-COVID/PASC, its underlying-suspected-pathologies, the pathobiological changes induced by TBI, in other words, the TBI endophenotypes, discuss the intersection of long-COVID/PASC and TBI-induced pathobiologies, and how by considering some of the known factors affecting the person's biological background and the inclusion of mechanistic molecular biomarkers can help to improve the clinical management of TBI patients.

[Predictors of thromboembolic complications in patients with severe SARS-CoV-2 coronavirus infection]

AIM

To identify predictors of the development of thromboembolic complications (TECs) in patients with severe SARS-CoV-2 coronavirus infection.

MATERIALS AND METHODS

A single-center observational retrospective study included 1634 patients with a confirmed diagnosis of SARS-CoV-2 coronavirus infection. The patients were divided into 2 groups depending on the availability of the feasibility study. The criterion for inclusion of patients in the main group was the presence of venous feasibility studies in 127 patients (group I), the comparison group consisted of 1507 patients in whom the course of COVID-19 was not complicated by the development of feasibility studies (group II).

RESULTS

When performing computed tomography of the chest organs, it was revealed that patients with a feasibility study had a higher percentage of lung tissue damage than patients in the comparison group: 55% [37.5; 67.5] and 37.5% [25.0; 47.5], respectively (p<0.001). The average values of C-reactive protein in I patients group were 129 [60.1; 211] ng/l, which was significantly higher than in II patients group - 41.0 [12.2; 97.6] ng/l (p<0.001), interleukin-6 - 176 [52.9; 471] pg/ml and 39.4 [11.0; 107] pg/ml (p<0.001), respectively. A one-factor regression analysis proved a significant contribution of comorbid pathology to the development of feasibility studies in patients with COVID-19. The presence of three nosologies at the same time: arterial hypertension, coronary heart disease (CHD) and chronic kidney disease increased the probability of a feasibility study by 4.81 times (odds ratio 4.8117, 95% confidence interval 3.2064-7.2207), in patients with arterial hypertension, CHD, chronic kidney disease and type 2 diabetes - by 5.63 times (odds ratio 5.6321, 95% confidence interval 3.1870-9.9531).

CONCLUSION

The presence of severe comorbid pathology significantly increased the risk of developing a feasibility study in patients with COVID-19. The most significant predictors of the development of feasibility studies in patients with severe SARS-CoV-2 coronavirus infection. They are: CHD, arterial hypertension and type 2 diabetes.

Viral anti-inflammatory serpin reduces immuno-coagulopathic pathology in SARS-CoV-2 mouse models of infection

SARS-CoV-2 acute respiratory distress syndrome (ARDS) induces uncontrolled lung inflammation and coagulopathy with high mortality. Anti-viral drugs and monoclonal antibodies reduce early COVID-19 severity, but treatments for late-stage immuno-thrombotic syndromes and long COVID are limited. Serine protease inhibitors (SERPINS) regulate activated proteases. The myxoma virus-derived Serp-1 protein is a secreted immunomodulatory serpin that targets activated thrombotic, thrombolytic, and complement proteases as a self-defense strategy to combat clearance. Serp-1 is effective in multiple animal models of inflammatory lung disease and vasculitis. Here, we describe systemic treatment with purified PEGylated Serp-1 as a therapy for immuno-coagulopathic complications during ARDS. Treatment with PEGSerp-1 in two mouse-adapted SARS-CoV-2 models in C57Bl/6 and BALB/c mice reduced lung and heart inflammation, with improved outcomes. PEGSerp-1 significantly reduced M1 macrophages in the lung and heart by modifying urokinase-type plasminogen activator receptor (uPAR), thrombotic proteases, and complement membrane attack complex (MAC). Sequential changes in gene expression for uPAR and serpins (complement and plasminogen inhibitors) were observed. PEGSerp-1 is a highly effective immune-modulator with therapeutic potential for severe viral ARDS, immuno-coagulopathic responses, and Long COVID.

Long COVID and risk of erectile dysfunction in recovered patients from mild to moderate COVID-19

Patients with coronavirus disease 2019 (COVID-19) were shown to have reduced serum testosterone levels compared to healthy individuals. Low testosterone levels are linked with the development of erectile dysfunction (ED). In this case-controlled study, 20 healthy controls and 39 patients with ED 3 months after recovering from mild-to-moderate COVID-19 pneumonia were studied. The patients ranged in age from 31 to 47 years. To identify early and late COVID-19 infections, real-time polymerase-chain reaction (RT-PCR) and COVID-19 antibody testing were done. The levels of luteinizing hormone (LH), follicular stimulating hormone (FSH), total testosterone (TT), free testosterone (FT), free androgenic index (FAI), and sex hormone-binding globulin (SHBG) were measured. The sexual health inventory for patients (SHIM) score was used to measure the erectile function of the patients and controls. When compared to the controls, the TT serum level in long COVID-19 (LC) patients with ED was low (p = 0.01). In contrast to controls, FT and FAI were both lower in LC patients with ED. (p = 0.001). FSH serum levels did not significantly differ (p = 0.07), but in ED patients, LH serum levels were elevated. SHIM scores were associated with low TT (p = 0.30), FT (p = 0.09), and high LH (p = 0.76) in LC patients with ED. Male patients with decreased serum levels of LH and testosterone may have hypothalamic-pituitary-gonadal axis dysfunction, which could lead to the development of LC-induced ED. Therefore, an in-depth research is necessary to confirm the causal link between COVID-19 and ED in LC patients.

Host-directed immunotherapy of viral and bacterial infections: past, present and future

The advent of COVID-19 and the persistent threat of infectious diseases such as tuberculosis, malaria, influenza and HIV/AIDS remind us of the marked impact that infections continue to have on public health. Some of the most effective protective measures are vaccines but these have been difficult to develop for some of these infectious diseases even after decades of research. The development of drugs and immunotherapies acting directly against the pathogen can be equally challenging, and such pathogen-directed therapeutics have the potential disadvantage of selecting for resistance. An alternative approach is provided by host-directed therapies, which interfere with host cellular processes required for pathogen survival or replication, or target the host immune response to infection (immunotherapies) to either augment immunity or ameliorate immunopathology. Here, we provide a historical perspective of host-directed immunotherapeutic interventions for viral and bacterial infections and then focus on SARS-CoV-2 and Mycobacterium tuberculosis, two major human pathogens of the current era, to indicate the key lessons learned and discuss candidate immunotherapeutic approaches, with a focus on drugs currently in clinical trials.

Long COVID: A New Challenge for Prevention of Obesity in Women

The long COVID affects individuals that do not recover for several weeks or months following the onset of symptoms of COVID-19. Obesity could play a role in the long COVID syndrome. During the pandemic, various factors contributed greatly to aggravating obesity in women leading to a pro-inflammatory and prothrombotic status. The present commentary explores the relationship between long COVID and obesity in women.

The trajectory of COVID-19 cardiopulmonary disease: insights from an autopsy study of community-based, pre-hospital deaths

Background

Post mortem examination of lung and heart tissue has been vital to developing an understanding of COVID-19 pathophysiology; however studies to date have almost uniformly used tissue obtained from hospital-based deaths where individuals have been exposed to major medical and pharmacological interventions.

Methods

In this study we investigated patterns of lung and heart injury from 46 community-based, pre-hospital COVID-19-attributable deaths who underwent autopsy.

Results

The cohort comprised 22 females and 24 males, median age 64 years (range 19-91) at time of death with illness duration range 0-23 days. Comorbidities associated with poor outcomes in COVID-19 included obesity (body mass index >30 kg·m-2) in 19 out of 46 cases (41.3%). Diffuse alveolar damage in its early exudative phase was the most common pattern of lung injury; however significant heterogeneity was identified with bronchopneumonia, pulmonary oedema consistent with acute cardiac failure, pulmonary thromboembolism and microthrombosis also identified and often in overlapping patterns. Review of clinical records and next of kin accounts suggested a combination of unexpectedly low symptom burden, rapidly progressive disease and psychosocial factors may have contributed to a failure of hospital presentation prior to death.

Conclusions

Identifying such advanced acute lung injury in community-based deaths is extremely unusual and raises the question why some with severe COVID-19 pneumonitis were not hospitalised. Multiple factors including low symptom burden, rapidly progressive disease trajectories and psychosocial factors provide possible explanations.

COVID-19 pandemic: A multidisciplinary perspective on the pathogenesis of a novel coronavirus from infection, immunity and pathological responses

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus2 (SARS-CoV-2), has spread to more than 200 countries and regions, having a huge impact on human health, hygiene, and economic activities. The epidemiological and clinical phenotypes of COVID-19 have increased since the onset of the epidemic era, and studies into its pathogenic mechanisms have played an essential role in clinical treatment, drug development, and prognosis prevention. This paper reviews the research progress on the pathogenesis of the novel coronavirus (SARS-CoV-2), focusing on the pathogenic characteristics, loci of action, and pathogenic mechanisms leading to immune response malfunction of SARS-CoV-2, as well as summarizing the pathological damage and pathological manifestations it causes. This will update researchers on the latest SARS-CoV-2 research and provide directions for future therapeutic drug development.

Comparison of Side Effects of COVID-19 Vaccines: Sinopharm, AstraZeneca, Sputnik V, and Covaxin in Women in Terms of Menstruation Disturbances, Hirsutism, and Metrorrhagia: A Descriptive-Analytical Cross-Sectional Study

BACKGROUND

Present study assessed whether Sinopharm, AstraZeneca, Sputnik V, and Covaxin's vaccinated women
reveal a distinct incidence of menstruation disturbances, hirsutism, and metrorrhagia.
Materials and Methods: Data collection was performed from June to August 2021, and 427 women working in seven
selected hospitals in Tehran were studied in this descriptive-analytical cross-sectional study. All of these women had
received one or both doses of the vaccines with one of the assessed vaccines. Required data was collected via questionnaire
and imported to SPSS 16 for further assessment and analysis. Fisher's Exact Test and Chi-Squared test were
main statistical tests used to understand whether any significant relation exists or not.
Results: The participant's mean age and body mass index (BMI) were 29.78 ± 10.55 and 23.27 ± 3.82, respectively.
Three hundred ninety-five cases (92.4%) had received both doses of the vaccines. Also, 154 cases (36.1%) had a history
of COVID-19. A total of 38 cases (8.8%) of menstruation disturbances, 20 cases (4.6%) of metrorrhagia, and 7
cases (1.6%) of hirsutism were reported after receiving the vaccines. There was a significant difference among the
vaccinated groups with the vaccines as mentioned earlier in terms of menstruation disturbances (hypermenorrhea,
dysmenorrhea, Amenorrhea) (P=0.01). The highest and the lowest incidence of menstruation disturbances were recorded
in the group vaccinated with Covaxin (17.6%) and Sputnik V (5%), respectively. There was also no significant
difference amongst the vaccinated groups with the four vaccines regarding the incidence of metrorrhagia and
hirsutism (P=0.10 and P=0.12, respectively). There was no significant relationship between all three complications
incidence with the previous infection concerning all vaccines (coefficient=0.46, 1.27, -0.15 respectively for menstruation
disturbances, metrorrhagia, and, hirsutism).
Conclusion: Seemingly, Covaxin revealed the most side effects in terms of menstruation disturbances. As a result, professionals
must carry out several studies with reasonable samples to recommend the vaccine to those women confidently.

Epidemiology and Management of Cerebral Venous Thrombosis during the COVID-19 Pandemic

Cerebral venous thrombosis (CVT) is a rare type of stroke that may cause an intracranial hypertension syndrome as well as focal neurological deficits due to venous infarcts. MRI with venography is the method of choice for diagnosis, and treatment with anticoagulants should be promptly started. CVT incidence has increased in COVID-19-infected patients due to a hypercoagulability state and endothelial inflammation. CVT following COVID-19 vaccination could be related to vaccine-induced immune thrombotic thrombocytopenia (VITT), a rare but severe complication that should be promptly identified because of its high mortality rate. Platelet count, D-dimer and PF4 antibodies should be dosed. Treatment with non-heparin anticoagulants and immunoglobulin could improve recuperation. Development of headache associated with seizures, impaired consciousness or focal signs should raise immediate suspicion of CVT. In patients who received a COVID-19 adenovirus-vector vaccine presenting thromboembolic events, VITT should be suspected and rapidly treated. Nevertheless, vaccination benefits clearly outweigh risks and should be continued.

Mast Cell Activation Syndrome in COVID-19 and Female Reproductive Function: Theoretical Background vs. Accumulating Clinical Evidence

Coronavirus disease 2019 (COVID-19), a pandemic disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, can affect almost all systems and organs of the human body, including those responsible for reproductive function in women. The multisystem inflammatory response in COVID-19 shows many analogies with mast cell activation syndrome (MCAS), and MCAS may be an important component in the course of COVID-19. Of note, the female sex hormones estradiol (E2) and progesterone (P4) significantly influence mast cell (MC) behavior. This review presents the importance of MCs and the mediators from their granules in the female reproductive system, including pregnancy, and discusses the mechanism of potential disorders related to MCAS. Then, the available data on COVID-19 in the context of hormonal disorders, the course of endometriosis, female fertility, and the course of pregnancy were compiled to verify intuitively predicted threats. Surprisingly, although COVID-19 hyperinflammation and post-COVID-19 illness may be rooted in MCAS, the available clinical data do not provide grounds for treating this mechanism as significantly increasing the risk of abnormal female reproductive function, including pregnancy. Further studies in the context of post COVID-19 condition (long COVID), where inflammation and a procoagulative state resemble many aspects of MCAS, are needed.

Subclinical myocardial injury, coagulopathy, and inflammation in COVID-19: A meta-analysis of 41,013 hospitalized patients

Background

Infection with the SARS-CoV-2 virus can lead to myocardial injury, evidenced by increases in specific biomarkers and imaging.

Objective

To quantify the association between biomarkers of myocardial injury, coagulation, and severe COVID-19 and death in hospitalized patients.

Methods

Studies were identified through a systematic search of indexed articles in PubMed, Embase, CINAHL, Cochrane, Web of Science, and Scopus, published between December 2019 to August 2021. Effect estimates from individual studies for association between markers of myocardial injury (Troponin), myocardial stretch (N-terminal-pro hormone BNP, NT-proBNP), and coagulopathy (D-Dimer) and death or severe/critical COVID-19 were pooled using inverse variance weighted random-effects model. Odds Ratios (OR), Hazard Ratios (HR), and 95% Confidence Intervals (CI) were pooled separately and reported by outcomes of critical/severe COVID-19 and death. A meta-analysis of proportions was also performed to summarize the pooled prevalence of co-morbidities in patients hospitalized with COVID-19.

Results

We included 62 articles, with a total of 41,013 patients. The pooled proportion of patients with history of hypertension was 39% (95% CI: 34-44%); diabetes, 21% (95% CI: 18%-24%); coronary artery disease, 13% (95% CI: 10-16%); chronic obstructive pulmonary disease, 7% (95% CI: 5-8%); and history of cancer, 5% (95% CI: 4-7%). Elevated troponin was associated with higher pooled odds of critical/severe COVID-19 and death [Odds Ratio (OR: 1.76, 95% CI: 1.42-2.16)]; and also separately for death (OR: 1.72, 95% CI: 1.32-2.25), and critical/severe COVID-1919 (OR: 1.93, 95% CI: 1.45-2.40). Elevations in NT-proBNP were also associated with higher severe COVID-19 and death (OR: 3.00, 95% CI: 1.58-5.70). Increases in D-dimer levels was also significantly associated with critical/severe COVID-19 and death (pooled OR: 1.38, 95% CI: 1.07-1.79).

Conclusions

This meta-analysis synthesizes existing evidence showing that myocardial injury, and coagulopathy are complications of COVID-19. The durability of these complications and their contributions to long-term cardiac implications of the disease is still being investigated. Patients who have recovered from COVID-19 may benefit from minimally invasive assessment for markers of myocardial injury, stretch and coagulopathy for early risk stratification purposes.

Cardiovascular complications in the Post-Acute COVID-19 syndrome (PACS)

•

The presence of stress-related (Takotsubo) cardiomyopathy has also been demonstrated in COVID-19.

•

The proposed mechanisms of cardiac damage during the acute phase of COVID-19 include both direct -viral penetration- and indirect routes -hypoxic injury and systemic inflammation.

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SARS-CoV-2 infection, especially in its severe form, is associated with an increased risk for venous thromboembolism (VTE).

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Unfractionated heparin (UFH) is the first-line treatment for hemodynamic instability and emergency reperfusion for PASC.

•

Further studies are needed to offer current screening for the occurrence of cardiovascular problems especially myocardial infarction and heart failure in COVID-19 patients.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV 2) or coronavirus disease 2019 (COVID-19) initially surfaced in December 2019 from Wuhan, China, sweeping the world with various strains, forcing the WHO to declare a pandemic epidemic in March 2020. Furthermore, COVID-19 manifests with a wide array of presentations from fever and fatigue to severe respiratory and cardiovascular complications. Post-COVID-19 syndrome is poorly understood affecting COVID-19 survivors at all levels of disease severity. The disease is most associated with post-discharge dyspnea and fatigue. However, other persistent symptoms as chest pains, palpitations, smell, and taste dysfunctions. Patients with high concentrations of CRP and creatinine in the acute phase of Covid-19 are more prone to cardiac sequelae. Therefore, high levels of cardiac-sensitive troponin and hypokalaemia can also be used for risk stratification. Furthermore, Cardiac damage can manifest as myocarditis, pericarditis, rhythm abnormalities. The use of different diagnostic modalities like electrocardiogram (ECG), echocardiogram, and cardiac magnetic resonance imaging (MRI)(CMR) to evaluate the myocardial damage were studied. However, Cardiovascular complications are a common manifestation of PASC, classification of severity of cardiac symptoms and the emergence of CMR as a diagnostic tool needs more evidence.

Impaired Vagal Activity in Long-COVID-19 Patients

Long-COVID-19 refers to the signs and symptoms that continue or develop after the “acute COVID-19” phase. These patients have an increased risk of multiorgan dysfunction, readmission, and mortality. In Long-COVID-19 patients, it is possible to detect a persistent increase in D-Dimer, NT-ProBNP, and autonomic nervous system dysfunction. To verify the dysautonomia hypothesis in Long-COVID-19 patients, we studied heart rate variability using 12-lead 24-h ECG monitoring in 30 Long-COVID-19 patients and 20 No-COVID patients. Power spectral analysis of heart rate variability was lower in Long-COVID-19 patients both for total power (7.46 ± 0.5 vs. 8.08 ± 0.6; p < 0.0001; Cohens-d = 1.12) and for the VLF (6.84 ± 0.8 vs. 7.66 ± 0.6; p < 0.0001; Cohens-d = 1.16) and HF (4.65 ± 0.9 vs. 5.33 ± 0.9; p = 0.015; Cohens-d = 0.76) components. The LF/HF ratio was significantly higher in Long-COVID-19 patients (1.46 ± 0.27 vs. 1.23 ± 0.13; p = 0.001; Cohens-d = 1.09). On multivariable analysis, Long-COVID-19 is significantly correlated with D-dimer (standardized β-coefficient = 0.259), NT-ProBNP (standardized β-coefficient = 0.281), HF component of spectral analysis (standardized β-coefficient = 0.696), and LF/HF ratio (standardized β-coefficient = 0.820). Dysautonomia may explain the persistent symptoms in Long COVID-19 patients. The persistence of a procoagulative state and an elevated myocardial strain could explain vagal impairment in these patients. In Long-COVID-19 patients, impaired vagal activity, persistent increases of NT-ProBNP, and a prothrombotic state require careful monitoring and appropriate intervention.

SARS-CoV-2 Infection and Lung Regeneration

The lung is the primary site of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced immunopathology whereby the virus enters the host cells by binding to angiotensin-converting enzyme 2 (ACE2). Sophisticated regeneration and repair programs exist in the lungs to replenish injured cell populations. However, known resident stem/progenitor cells have been demonstrated to express ACE2, raising a substantial concern regarding the long-term consequences of impaired lung regeneration after SARS-CoV-2 infection. Moreover, clinical treatments may also affect lung repair from antiviral drug candidates to mechanical ventilation. In this review, we highlight how SARS-CoV-2 disrupts a program that governs lung homeostasis. We also summarize the current efforts of targeted therapy and supportive treatments for COVID-19 patients. In addition, we discuss the pros and cons of cell therapy with mesenchymal stem cells or resident lung epithelial stem/progenitor cells in preventing post-acute sequelae of COVID-19. We propose that, in addition to symptomatic treatments being developed and applied in the clinic, targeting lung regeneration is also essential to restore lung homeostasis in COVID-19 patients.

A Scoping Review of Pharmacological Management of Postacute Sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 Infection in 2021

BACKGROUND

Postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection (PASC), or long-COVID, are signs and symptoms that persist after the acute phase of Coronavirus disease 2019 infection has passed. PASC is newly recognized, and research is ongoing to answer questions about pathology, symptoms, diagnosis, and optimal treatment.

AREAS OF UNCERTAINTY

Use of pharmacologic treatment for symptoms of PASC is currently evolving. This scoping review aims to assess medical literature for any evidence supporting or refuting use of any medications to specifically treat PASC.

DATA SOURCES

PubMed, EMBASE, Web of Science, and gray literature sources were searched for any study of medication use for PASC. Studies were included if they described medication use in patients with PASC. There were no exclusion criteria based on study type or if results were reported. Studies were divided into completed works and ongoing research.

RESULTS

Fifty-two records were included in final analysis from an initial 3524 records found, including 2 randomized controlled trials, 7 prospective, open-label or observational studies, 14 case reports or case series, 1 survey, 1 correspondence, 1 retrospective analysis, and 26 studies in progress. Seven of the 26 completed works investigate ivabradine or beta-blockers, whereas 7 investigate local or systemic corticosteroids. Three investigate multi-ingredient nutritional supplements. The other 9 completed works as well as the 26 studies in progress investigate a wide variety of other treatments including drugs in development, drugs used for other conditions, herbals, supplements, and vitamins.

CONCLUSIONS

There is limited, but evolving, literature on medication treatment for PASC. Providers who opt to use pharmacologic therapy for PASC need to be vigilant in their knowledge of these evolving data.

Cardiovascular Complications of COVID-19 Vaccines

Coronavirus disease 2019 (COVID-19) has become a global public health catastrophe. Vaccination against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is proven to be the most effective measure to suppress the pandemic. With the widespread application of the four vaccines, namely, ChAdOx1, Ad26.COV2.S, BNT162b2, and mRNA-1273.2, several adverse effects have been reported. The most serious type of complication is cardiovascularly related, including myocarditis, immune thrombocytopenia (ITP), cerebral sinus venous thrombosis, among others. All these adverse events undermine the health of the vaccinees and affect the administration of the vaccines. As the distribution of COVID-19 vaccines is surrounded by suspicion and rumors, it is essential to provide the public with accurate reports from trusted experts and journals. Monitoring the safety of COVID-19 vaccines is an important and ongoing process that is also urgent. Thus, we summarized the cardiovascular complications of the major types of COVID-19 vaccines, including mRNA vaccines, which are now generally considered to be innovative vaccines, and the future for vaccination against COVID-19, in addition to the underlying pathogenesis and potential therapeutics.

COVID-19, Vaccines, and Thrombotic Events: A Narrative Review

The coronavirus disease 2019 (COVID-19), a deadly pandemic that has affected millions of people worldwide, is associated with cardiovascular complications, including venous and arterial thromboembolic events. Viral spike proteins, in fact, may promote the release of prothrombotic and inflammatory mediators. Vaccines, coding for the spike protein, are the primary means for preventing COVID-19. However, some unexpected thrombotic events at unusual sites, most frequently located in the cerebral venous sinus but also splanchnic, with associated thrombocytopenia, have emerged in subjects who received adenovirus-based vaccines, especially in fertile women. This clinical entity was soon recognized as a new syndrome, named vaccine-induced immune thrombotic thrombocytopenia, probably caused by cross-reacting anti-platelet factor-4 antibodies activating platelets. For this reason, the regulatory agencies of various countries restricted the use of adenovirus-based vaccines to some age groups. The prevailing opinion of most experts, however, is that the risk of developing COVID-19, including thrombotic complications, clearly outweighs this potential risk. This point-of-view aims at providing a narrative review of epidemiological issues, clinical data, and pathogenetic hypotheses of thrombosis linked to both COVID-19 and its vaccines, helping medical practitioners to offer up-to-date and evidence-based counseling to their often-alarmed patients with acute or chronic cardiovascular thrombotic events.

Prothrombotic Phenotype in COVID-19: Focus on Platelets

COVID-19 infection is associated with a broad spectrum of presentations, but alveolar capillary microthrombi have been described as a common finding in COVID-19 patients, appearing as a consequence of a severe endothelial injury with endothelial cell membrane disruption. These observations clearly point to the identification of a COVID-19-associated coagulopathy, which may contribute to thrombosis, multi-organ damage, and cause of severity and fatality. One significant finding that emerges in prothrombotic abnormalities observed in COVID-19 patients is that the coagulation alterations are mainly mediated by the activation of platelets and intrinsically related to viral-mediated endothelial inflammation. Beyond the well-known role in hemostasis, the ability of platelets to also release various potent cytokines and chemokines has elevated these small cells from simple cell fragments to crucial modulators in the blood, including their inflammatory functions, that have a large influence on the immune response during infectious disease. Indeed, platelets are involved in the pathogenesis of acute lung injury also by promoting NET formation and affecting vascular permeability. Specifically, the deposition by activated platelets of the chemokine platelet factor 4 at sites of inflammation promotes adhesion of neutrophils on endothelial cells and thrombogenesis, and it seems deeply involved in the phenomenon of vaccine-induced thrombocytopenia and thrombosis. Importantly, the hyperactivated platelet phenotype along with evidence of cytokine storm, high levels of P-selectin, D-dimer, and, on the other hand, decreased levels of fibrinogen, von Willebrand factor, and thrombocytopenia may be considered suitable biomarkers that distinguish the late stage of COVID-19 progression in critically ill patients.