Impaired Endothelial Function in Convalescent Phase of COVID-19: A 3 Month Follow Up Observational Prospective Study

Cutting-Edge Techniques and Drugs for the Treatment of Pulmonary Embolism: Current Knowledge and Future Perspectives

Pulmonary embolism (PE) is a potentially life-threatening condition requiring prompt diagnosis and treatment. Recent advances have led to the development of newer techniques and drugs aimed at improving PE management, reducing its associated morbidity and mortality and the complications related to anticoagulation. This review provides an overview of the current knowledge and future perspectives on PE treatment. Anticoagulation represents the first-line treatment of hemodynamically stable PE, direct oral anticoagulants being a safe and effective alternative to traditional anticoagulation: these drugs have a rapid onset of action, predictable pharmacokinetics, and low bleeding risk. Systemic fibrinolysis is suggested in patients with cardiac arrest, refractory hypotension, or shock due to PE. With this narrative review, we aim to assess the state of the art of newer techniques and drugs that could radically improve PE management in the near future: (i) mechanical thrombectomy and pulmonary embolectomy are promising techniques reserved to patients with massive PE and contraindications or failure to systemic thrombolysis; (ii) catheter-directed thrombolysis is a minimally invasive approach that can be suggested for the treatment of massive or submassive PE, but the lack of large, randomized controlled trials represents a limitation to widespread use; (iii) novel pharmacological approaches, by agents inhibiting thrombin-activatable fibrinolysis inhibitor, factor Xia, and the complement cascade, are currently under investigation to improve PE-related outcomes in specific settings.

Endothelial Extracellular Vesicles Enriched in microRNA-34a Predict New-Onset Diabetes in Coronavirus Disease 2019 (COVID-19) Patients: Novel Insights for Long COVID Metabolic Sequelae

Emerging evidence indicates that the relationship between coronavirus disease 2019 (COVID-19) and diabetes is 2-fold: 1) it is known that the presence of diabetes and other metabolic alterations poses a considerably high risk to develop a severe COVID-19; 2) patients who survived a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have an increased risk of developing new-onset diabetes. However, the mechanisms underlying this association are mostly unknown, and there are no reliable biomarkers to predict the development of new-onset diabetes. In the present study, we demonstrate that a specific microRNA (miR-34a) contained in circulating extracellular vesicles released by endothelial cells reliably predicts the risk of developing new-onset diabetes in COVID-19. This association was independent of age, sex, body mass index (BMI), hypertension, dyslipidemia, smoking status, and D-dimer. SIGNIFICANCE STATEMENT: We demonstrate for the first time that a specific microRNA (miR-34a) contained in circulating extracellular vesicles released by endothelial cells is able to reliably predict the risk of developing diabetes after having contracted coronavirus disease 2019 (COVID-19). This association was independent of age, sex, body mass index (BMI), hypertension, dyslipidemia, smoking status, and D-dimer. Our findings are also relevant when considering the emerging importance of post-acute sequelae of COVID-19, with systemic manifestations observed even months after viral negativization (long COVID).

SARS-CoV-2 induced vascular endothelial dysfunction: direct or indirect effects?

Clinical evidence reveals that manifestations of endothelial dysfunction are widely observed in COVID-19 and long-COVID patients. However, whether these detrimental effects are caused by direct infection of the endothelium or are indirectly mediated by systemic inflammation has been a matter of debate. It has been well acknowledged that endothelial cells (ECs) of the cardiovascular system ubiquitously express the SARS-CoV-2 entry receptor angiotensin-converting enzyme 2 (ACE2), yet accumulating evidence suggests that it is more predominantly expressed by pericytes and vascular smooth muscle cells of the mammalian blood vessel. Besides, replicative infection of ECs by SARS-CoV-2 has yet to be demonstrated both in vitro and in vivo. In this study, we review latest research on endothelial ACE2 expression in different vascular beds, and the heterogeneity in various EC subsets with differential ACE2 expression in response to SARS-CoV-2. We also discuss ACE2-independent alternative mechanisms underlying endothelial activation in COVID-19, and the clinical manifestations of SARS-CoV-2-induced endothelial dysfunction. Altogether, understanding ACE2-dependent and ACE2-independent mechanisms driving SARS-CoV-2-induced vascular dysfunction would shed light on strategies of more effective therapies targeting cardiovascular complications associated with COVID-19.

SGLT2 Inhibitors in Long COVID Syndrome: Is There a Potential Role?

The coronavirus disease (COVID)-19 has turned into a pandemic causing a global public health crisis. While acute COVID-19 mainly affects the respiratory system and can cause acute respiratory distress syndrome, an association with persistent inflammatory stress affecting different organ systems has been elucidated in long COVID syndrome (LCS). Increased severity and mortality rates have been reported due to cardiophysiological and metabolic systemic disorders as well as multiorgan failure in COVID-19, additionally accompanied by chronic dyspnea and fatigue in LCS. Hence, novel therapies have been tested to improve the outcomes of LCS of which one potential candidate might be sodium-glucose cotransporter 2 (SGLT2) inhibitors. The aim of this narrative review was to discuss rationales for investigating SGLT2 inhibitor therapy in people suffering from LCS. In this regard, we discuss their potential positive effects-next to the well described "cardio-renal-metabolic" conditions-with a focus on potential anti-inflammatory and beneficial systemic effects in LCS. However, potential beneficial as well as potential disadvantageous effects of SGLT2 inhibitors on the prevalence and long-term outcomes of COVID-19 will need to be established in ongoing research.

The Relationship between Post-COVID Syndrome and the Burden of Comorbidities Assessed Using the Charlson Comorbidity Index

Introduction: The post-COVID-19 syndrome is a clinical entity characterized by the manifestation of signs and symptoms that develop after the acute phase of COVID-19, which persist for a duration of more than 12 weeks and are not explained by any alternative diagnosis. It has been observed that individuals with pre-existing chronic diseases, including cardiovascular and pulmonary diseases, are at a greater risk of developing post-COVID-19 syndrome. The Charlson Comorbidity Index (CCI) is a useful tool employed to evaluate the burden of comorbidities and predict the prognosis of patients with post-COVID-19 syndrome. The present study aims to assess whether the burden of comorbidities, evaluated using the CCI, correlates with post-COVID-19 syndrome. Materials and Methods: Between 21 April 2020 and 15 May 2023, we enrolled all consecutive outpatients with previous COVID-19 admissions to a post-acute day-hospital service three months after a negative SARS-CoV-2 molecular test. We assessed age, sex, BMI, acute COVID-19 and post-COVID-19 signs, and symptoms and calculated CCI according to its current definition. Post-COVID-19 syndrome was defined as the persistence of at least one sign or symptom lasting more than 12 weeks after COVID-19 resolution and not explained by an alternative diagnosis. The relationship between post-COVID-19 and CCI was explored first with the chi-squared test, then with different binary logistic regression models. We considered significant values of p lower than 0.05. Results: We obtained a cohort of 3636 patients and observed a significant association between the number of post-COVID-19 symptoms and CCI. Patients developing post-COVID-19 were more commonly affected by a greater burden of comorbidities. Patients with at least one CCI point had an increased risk of post-COVID-19 syndrome (OR:2.961; 95%CI: 2.269-3.863; p < 0.0001), which increased further for CCI ≥ 4 (OR:6.062; 95%CI: 3.163-11.618; p < 0.0001). Conclusions: Patients affected by post-COVID-19 show a greater clinical complexity and a larger burden of comorbidities, synthesized by a higher CCI; moreover, a higher CCI seems to correlate with an increasing post-COVID-19 risk, being the presence of ≥1 or ≥4 CCI points associated with a 3-fold and 6-fold increased risk of post-COVID-19 syndrome, respectively.

Role of Endothelium in Cardiovascular Sequelae of Long COVID

The global action against coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 infection, shed light on endothelial dysfunction. Although SARS-CoV-2 primarily affects the pulmonary system, multiple studies have documented pan-vascular involvement in COVID-19. The virus is able to penetrate the endothelial barrier, damaging it directly or indirectly and causing endotheliitis and multi-organ injury. Several mechanisms cooperate to development of endothelial dysfunction, including endothelial cell injury and pyroptosis, hyperinflammation and cytokine storm syndrome, oxidative stress and reduced nitric oxide bioavailability, glycocalyx disruption, hypercoagulability, and thrombosis. After acute-phase infection, some patients reported signs and symptoms of a systemic disorder known as long COVID, in which a broad range of cardiovascular (CV) disorders emerged. To date, the exact pathophysiology of long COVID remains unclear: in addition to the persistence of acute-phase infection mechanisms, specific pathways of CV damage have been postulated, such as persistent viral reservoirs in the heart or an autoimmune response to cardiac antigens through molecular mimicry. The aim of this review is to provide an overview of the main molecular patterns of enduring endothelial activation following SARS-CoV-2 infection and to offer the latest summary of CV complications in long COVID.

Long-term hypercoagulability, endotheliopathy and inflammation following acute SARS-CoV-2 infection

INTRODUCTION

both symptomatic and asymptomatic SARS-CoV-2 infections - coined Coronavirus disease 2019 (COVID-19) - have been linked to a higher risk of cardiovascular events after recovery.

AREAS COVERED

our review aims to summarize the latest evidence on the increased thrombotic and cardiovascular risk in recovered COVID-19 patients and to examine the pathophysiological mechanisms underlying the interplay among endothelial dysfunction, inflammatory response and coagulation in long-COVID. We performed a systematic search of studies on hypercoagulability, endothelial dysfunction and inflammation after SARS-CoV-2 infection.

EXPERT OPINION

endothelial dysfunction is a major pathophysiological mechanism responsible for most clinical manifestations in COVID-19. The pathological activation of endothelial cells by a virus infection results in a pro-adhesive and chemokine-secreting phenotype, which in turn promotes the recruitment of circulating leukocytes. Cardiovascular events after COVID-19 appear to be related to persistent immune dysregulation. Patients with long-lasting symptoms display higher amounts of proinflammatory molecules such as tumor necrosis factor-α, interferon γ and interleukins 2 and 6. Immune dysregulation can trigger the activation of the coagulation pathway. The formation of extensive microclots in vivo, both during acute COVID-19 and in long-COVID-19, appears to be a relevant mechanism responsible for persistent symptoms and cardiovascular events.

ME/CFS and Long COVID share similar symptoms and biological abnormalities: road map to the literature

Some patients remain unwell for months after "recovering" from acute COVID-19. They develop persistent fatigue, cognitive problems, headaches, disrupted sleep, myalgias and arthralgias, post-exertional malaise, orthostatic intolerance and other symptoms that greatly interfere with their ability to function and that can leave some people housebound and disabled. The illness (Long COVID) is similar to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) as well as to persisting illnesses that can follow a wide variety of other infectious agents and following major traumatic injury. Together, these illnesses are projected to cost the U.S. trillions of dollars. In this review, we first compare the symptoms of ME/CFS and Long COVID, noting the considerable similarities and the few differences. We then compare in extensive detail the underlying pathophysiology of these two conditions, focusing on abnormalities of the central and autonomic nervous system, lungs, heart, vasculature, immune system, gut microbiome, energy metabolism and redox balance. This comparison highlights how strong the evidence is for each abnormality, in each illness, and helps to set priorities for future investigation. The review provides a current road map to the extensive literature on the underlying biology of both illnesses.

Vascular mechanisms of post-COVID-19 conditions: Rho-kinase is a novel target for therapy

BACKGROUND

In post-coronavirus disease-19 (post-COVID-19) conditions (long COVID), systemic vascular dysfunction is implicated, but the mechanisms are uncertain, and the treatment is imprecise.

METHODS AND RESULTS

Patients convalescing after hospitalization for COVID-19 and risk factor matched controls underwent multisystem phenotyping using blood biomarkers, cardiorenal and pulmonary imaging, and gluteal subcutaneous biopsy (NCT04403607). Small resistance arteries were isolated and examined using wire myography, histopathology, immunohistochemistry, and spatial transcriptomics. Endothelium-independent (sodium nitroprusside) and -dependent (acetylcholine) vasorelaxation and vasoconstriction to the thromboxane A2 receptor agonist, U46619, and endothelin-1 (ET-1) in the presence or absence of a RhoA/Rho-kinase inhibitor (fasudil), were investigated. Thirty-seven patients, including 27 (mean age 57 years, 48% women, 41% cardiovascular disease) 3 months post-COVID-19 and 10 controls (mean age 57 years, 20% women, 30% cardiovascular disease), were included. Compared with control responses, U46619-induced constriction was increased (P = 0.002) and endothelium-independent vasorelaxation was reduced in arteries from COVID-19 patients (P < 0.001). This difference was abolished by fasudil. Histopathology revealed greater collagen abundance in COVID-19 arteries {Masson's trichrome (MT) 69.7% [95% confidence interval (CI): 67.8-71.7]; picrosirius red 68.6% [95% CI: 64.4-72.8]} vs. controls [MT 64.9% (95% CI: 59.4-70.3) (P = 0.028); picrosirius red 60.1% (95% CI: 55.4-64.8), (P = 0.029)]. Greater phosphorylated myosin light chain antibody-positive staining in vascular smooth muscle cells was observed in COVID-19 arteries (40.1%; 95% CI: 30.9-49.3) vs. controls (10.0%; 95% CI: 4.4-15.6) (P < 0.001). In proof-of-concept studies, gene pathways associated with extracellular matrix alteration, proteoglycan synthesis, and viral mRNA replication appeared to be upregulated.

CONCLUSION

Patients with post-COVID-19 conditions have enhanced vascular fibrosis and myosin light change phosphorylation. Rho-kinase activation represents a novel therapeutic target for clinical trials.

Imbalance of Peripheral Temperature, Sympathovagal, and Cytokine Profile in Long COVID

A persistent state of inflammation has been reported during the COVID-19 pandemic. This study aimed to assess short-term heart rate variability (HRV), peripheral body temperature, and serum cytokine levels in patients with long COVID. We evaluated 202 patients with long COVID symptoms categorized them according to the duration of their COVID symptoms (≤120 days, n = 81; >120 days, n = 121), in addition to 95 healthy individuals selected as controls. All HRV variables differed significantly between the control group and patients with long COVID in the ≤120 days group (p < 0.05), and participants in the long COVID ≤120 days group had higher temperatures than those in the long COVID >120 days group in all regions analysed (p < 0.05). Cytokine analysis showed higher levels of interleukin 17 (IL-17) and interleukin 2 (IL-2), and lower levels of interleukin 4 (IL-4) (p < 0.05). Our results suggest a reduction in parasympathetic activation during long COVID and an increase in body temperature due to possible endothelial damage caused by the maintenance of elevated levels of inflammatory mediators. Furthermore, high serum levels of IL-17 and IL-2 and low levels of IL-4 appear to constitute a long-term profile of COVID-19 cytokines, and these markers are potential targets for long COVID-treatment and prevention strategies.

Targeted Blood Plasma Proteomics and Hemostasis Assessment of Post COVID-19 Patients with Acute Myocardial Infarction

The molecular mechanisms underlying cardiovascular complications after the SARS-CoV-2 infection remain unknown. The goal of our study was to analyze the features of blood coagulation, platelet aggregation, and plasma proteomics in COVID-19 convalescents with AMI. The study included 66 AMI patients and 58 healthy volunteers. The groups were divided according to the anti-N IgG levels (AMI post-COVID (n = 44), AMI control (n = 22), control post-COVID (n = 31), and control (n = 27)). All participants underwent rotational thromboelastometry, thrombodynamics, impedance aggregometry, and blood plasma proteomics analysis. Both AMI groups of patients demonstrated higher values of clot growth rates, thrombus size and density, as well as the elevated levels of components of the complement system, proteins modifying the state of endothelium, acute-phase and procoagulant proteins. In comparison with AMI control, AMI post-COVID patients demonstrated decreased levels of proteins connected to inflammation and hemostasis (lipopolysaccharide-binding protein, C4b-binding protein alpha-chain, plasma protease C1 inhibitor, fibrinogen beta-chain, vitamin K-dependent protein S), and altered correlations between inflammation and fibrinolysis. A new finding is that AMI post-COVID patients opposite the AMI control group, are characterized by a less noticeable growth of acute-phase proteins and hemostatic markers that could be explained by prolonged immune system alteration after COVID-19.

Effects of l-Arginine Plus Vitamin C Supplementation on Physical Performance, Endothelial Function, and Persistent Fatigue in Adults with Long COVID: A Single-Blind Randomized Controlled Trial

Long COVID, a condition characterized by symptom and/or sign persistence following an acute COVID-19 episode, is associated with reduced physical performance and endothelial dysfunction. Supplementation of l-arginine may improve endothelial and muscle function by stimulating nitric oxide synthesis. A single-blind randomized, placebo-controlled trial was conducted in adults aged between 20 and 60 years with persistent fatigue attending a post-acute COVID-19 outpatient clinic. Participants were randomized 1:1 to receive twice-daily orally either a combination of 1.66 g l-arginine plus 500 mg liposomal vitamin C or a placebo for 28 days. The primary outcome was the distance walked on the 6 min walk test. Secondary outcomes were handgrip strength, flow-mediated dilation, and fatigue persistence. Fifty participants were randomized to receive either l-arginine plus vitamin C or a placebo. Forty-six participants (median (interquartile range) age 51 (14), 30 [65%] women), 23 per group, received the intervention to which they were allocated and completed the study. At 28 days, l-arginine plus vitamin C increased the 6 min walk distance (+30 (40.5) m; placebo: +0 (75) m, p = 0.001) and induced a greater improvement in handgrip strength (+3.4 (7.5) kg) compared with the placebo (+1 (6.6) kg, p = 0.03). The flow-mediated dilation was greater in the active group than in the placebo (14.3% (7.3) vs. 9.4% (5.8), p = 0.03). At 28 days, fatigue was reported by two participants in the active group (8.7%) and 21 in the placebo group (80.1%; p < 0.0001). l-arginine plus vitamin C supplementation improved walking performance, muscle strength, endothelial function, and fatigue in adults with long COVID. This supplement may, therefore, be considered to restore physical performance and relieve persistent symptoms in this patient population.

Pulmonale Manifestationen bei Long-COVID

Hintergrund

Pulmonale Manifestationen sind sehr häufige Folgeerscheinungen nach einer Severe-acute-respiratory-syndrome-coronavirus-type-2(SARS-CoV-2)-Infektion, die unter dem Begriff Long-COVID-Syndrom (COVID „coronavirus disease“) zusammengefasst werden.

Ziel und Methoden

Zusammenfassung der aktuellen Literatur zu den pulmonalen Manifestationen mit einem Fokus auf Expertenempfehlungen.

Ergebnisse

Dyspnoe ist nach der chronischen Fatigue das häufigste Symptom bei Patienten mit Long-COVID-Syndrom. Auffällige Befunde finden sich vor allem nach schwerem akutem COVID-19-Verlauf und beinhalten radiologische Veränderungen im Sinne interstitieller Lungenerkrankungen, restriktive lungenfunktionelle Befunde und Einschränkungen der Diffusionskapazität als häufigsten pathologischen Befund. Obwohl sich sowohl Beschwerden als auch pathologische pulmonale Befunde im Verlauf bessern, können einige Patienten noch Monate nach der akuten Infektion unter Auffälligkeiten leiden. Dabei ist die Relevanz der pathologischen Befunde sowie eine Beteiligung funktioneller respiratorischer Einschränkungen, einer kardiopulmonalen Dekonditionierung, nichtsomatischer Ursachen und vorbestehender Erkrankungen aktuell unklar. Die diagnostische Abklärung fokussiert entsprechend auf Risikopatienten und schließt neben einer bildgebenden und lungenfunktionellen Abklärung eine Belastungsuntersuchung und bei unklaren Befunden eine Echokardiographie zur Diagnose einer pulmonalvaskulären Komponente ein. Die therapeutischen Möglichkeiten beinhalten aktuell die leitliniengerechte Therapie von Ursachen der Beschwerden (beispielsweise interstitielle Lungenerkrankungen, Husten) und Rehabilitationsmaßnahmen.

Schlussfolgerung

Das aktuelle Wissen zum Krankheitsbild wird ständig erweitert, allerdings existieren aufgrund mangelnder Studienlage noch keine evidenzbasierten Leitlinien zur Diagnostik und Therapie pulmonaler Manifestationen beim Long-COVID-Syndrom.

Radial Peripapillary Capillary Plexus Perfusion and Endothelial Dysfunction in Early Post-SARS-CoV-2 Infection

Background: Endothelial cells damage and thromboinflammation are considered key elements in the generation of organ impairment in patients with COVID-19 disease. The endothelial function is evaluated by measuring flow-mediated dilation (FMD). We aimed to analyze the association between FMD impairment and retinal vascular parameters in early post-COVID-19 patients. 00118-00199Tomography (OCT), OCT Angiography (OCTA) and slit lamp examination were performed. FMD ≤ 7% was considered as pathological. Our primary outcome was to assess potential differences in the radial peripapillary capillary plexus flow index (RPCP-FI) and RPCP density (RPCP-D) values between post-COVID-19 patients with and without FMD impairment. The associations of other retinal vascular parameters with FMD impairment were assessed as secondary endpoints. Results: FMD impairment was detected in 31 patients (37.8%). RPCP-FI (p = 0.047), age (p = 0.048) and prevalence of diabetes (p = 0.046) significantly differed in patients with FMD ≤ 7% in regression analysis. RPCP-FI was linearly correlated with FMD values (R = 0.244, p =0.027). SCT was found to be lower in patients with impaired FMD (p = 0.004), although this difference was only a trend in binary logistic regression output (p = 0.07). Conclusions: Early post-COVID-19 patients showed a higher prevalence of FMD impairment compared to the general population. Age, diabetes and RPCP-FI were independently correlated with the presence of endothelial impairment in the early post-infective period.