Endothelial function provides early prognostic information in patients with COVID-19: A cohort study

Recovery of Endothelium-dependent vascular relaxation impairment in convalescent COVID-19 patients: Insight from a pilot study

BACKGROUND

Endothelial dysfunction is a key-feature in acute COVID-19. However, follow-up data regarding endothelial dysfunction and injury after COVID-19 infection are lacking. We aimed to investigate the changes in endothelium-dependent vasorelaxation at baseline and four months after hospital discharge in COVID-19 patients.

METHODS

Twenty COVID-19 patients were compared to 24 healthy controls. Clinical and morphological data were collected after hospital admission for SARS-CoV-2 infection and reactive hyperaemia index (RHI) measurement was performed with a delay between 24 and 48 h after hospital admission and four months after hospital discharge in the outpatient clinics. Blood tests including inflammatory markers and measurement of post-occlusive vasorelaxation by digital peripheral arterial tonometry were performed at both visits.

RESULTS

At baseline, COVID-19 patients exhibited reduced RHI compared to controls (p < 0.001), in line with an endothelial dysfunction. At four months follow-up, there was a 51% increase in the RHI (1.69 ± 0.32 to 2.51 ± 0.91; p < 0.01) in favor of endothelium-dependent vascular relaxation recovery. RHI changes were positively correlated with baseline C-reactive protein (r = 0.68; p = 0.02). Compared to COVID-19 patients with a decrease in RHI, COVID-19 patients with an increase in RHI beyond the day-to-day variability (i.e. >11%) had less severe systemic inflammation at baseline.

CONCLUSION

Convalescent COVID-19 patients showed a recovery of systemic artery endothelial dysfunction, in particular patients with lower inflammation at baseline. Further studies are needed to decipher the interplay between inflammation and endothelial dysfunction in COVID-19 patients.

Pathophysiological Aspects of COVID-19-Associated Vasculopathic Diseases

Since the beginning of coronavirus disease 2019 (COVID-19) pandemic, numerous data reported potential effects on the cardiovascular system due to infection by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), which may lead to COVID-19-associated vasculopathies during the acute phase and measurable vascular changes in the convalescent phase. Infection by SARS-CoV-2 seems to have specific direct and indirect effects on the endothelium, immune and coagulation systems thus promoting endothelial dysfunction, immunothrombosis, and formation of neutrophil extracellular traps although the exact mechanisms still need to be elucidated. This review represents a recent update of pathophysiological pathways of the respective three major mechanisms contributing to COVID-19 vasculopathies and vascular changes and includes clinical implications and significance of outcome data.

Endothelial dysfunction in COVID-19: an overview of evidence, biomarkers, mechanisms and potential therapies

The fight against coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection is still raging. However, the pathophysiology of acute and post-acute manifestations of COVID-19 (long COVID-19) is understudied. Endothelial cells are sentinels lining the innermost layer of blood vessel that gatekeep micro- and macro-vascular health by sensing pathogen/danger signals and secreting vasoactive molecules. SARS-CoV-2 infection primarily affects the pulmonary system, but accumulating evidence suggests that it also affects the pan-vasculature in the extrapulmonary systems by directly (via virus infection) or indirectly (via cytokine storm), causing endothelial dysfunction (endotheliitis, endothelialitis and endotheliopathy) and multi-organ injury. Mounting evidence suggests that SARS-CoV-2 infection leads to multiple instances of endothelial dysfunction, including reduced nitric oxide (NO) bioavailability, oxidative stress, endothelial injury, glycocalyx/barrier disruption, hyperpermeability, inflammation/leukocyte adhesion, senescence, endothelial-to-mesenchymal transition (EndoMT), hypercoagulability, thrombosis and many others. Thus, COVID-19 is deemed as a (micro)vascular and endothelial disease. Of translational relevance, several candidate drugs which are endothelial protective have been shown to improve clinical manifestations of COVID-19 patients. The purpose of this review is to provide a latest summary of biomarkers associated with endothelial cell activation in COVID-19 and offer mechanistic insights into the molecular basis of endothelial activation/dysfunction in macro- and micro-vasculature of COVID-19 patients. We envisage further development of cellular models and suitable animal models mimicking endothelial dysfunction aspect of COVID-19 being able to accelerate the discovery of new drugs targeting endothelial dysfunction in pan-vasculature from COVID-19 patients.

Current topic of vascular function in hypertension

Vascular function assessment is useful for the evaluation of atherosclerosis severity, which may provide additional information for cardiovascular risk stratification. In addition, vascular function assessment is helpful for a better understanding of pathophysiological associations between vascular dysfunction and cardiometabolic disorders. In 2020 and 2021, although coronavirus disease 2019 (COVID-19) was still a worldwide challenge for health care systems, many excellent articles regarding vascular function were published in Hypertension Research and other major cardiovascular and hypertension journals. In this review, we summarize new findings on vascular function and discuss the association between vascular function and COVID-19, the importance of lifestyle modifications for the maintenance of vascular function, and the usefulness of vascular function tests for cardiovascular risk assessment. We hope this review will be helpful for the management of cardiovascular risk factors, including hypertension and cardiovascular diseases, in clinical practice.

Clinical implications of vascular dysfunction in acute and convalescent COVID-19: A systematic review

BACKGROUND

Accumulating evidence suggests that endothelial dysfunction is implicated in the pathogenesis and severity of coronavirus disease 2019 (COVID-19). In this context, vascular impairment in COVID-19 might be associated with clinical manifestations and could refine risk stratification in these patients.

METHODS

This systematic review aims to synthesize current evidence on the frequency and the prognostic value of vascular dysfunction during acute and post-recovery COVID-19. After systematically searching the MEDLINE, clinicaltrials.gov and the Cochrane Library from 1 December 2019 until 05 March 2022, we identified 24 eligible studies with laboratory confirmed COVID-19 and a thorough examination of vascular function. Flow-mediated dilation (FMD) was assessed in 5 and 12 studies in acute and post-recovery phase respectively; pulse wave velocity (PWV) was the marker of interest in three studies in the acute and four studies in the post-recovery phase.

RESULTS

All studies except for one in the acute and in the post-recovery phase showed positive association between vascular dysfunction and COVID-19 infection. Endothelial dysfunction in two studies and increased arterial stiffness in three studies were related to inferior survival in COVID-19.

DISCUSSION

Overall, a detrimental effect of COVID-19 on markers of endothelial function and arterial stiffness that could persist even for months after the resolution of the infection and provide prognostic value was congruent across published studies. Further research is warranted to elucidate clinical implications of this association.

Vaccination Against SARS-CoV-2 Protects from COVID-19-induced Endothelial Dysfunction

BACKGROUND

Coronavirus Disease-19 (COVID-19) is implicated in endotheliitis, which adversely affects cardiovascular events. The impact of vaccination with COVID-19 on the clinical outcome of patients is documented.

OBJECTIVE

To evaluate the impact of vaccination with COVID-19 on the severe acute respiratory syndrome, coronavirus-2 (SARS-CoV-2) infection-related endothelial impairment.

METHODS

We enrolled 45 patients hospitalized for COVID-19 (either vaccinated or not against SARS-CoV-2). Clinical and laboratory data were collected, and brachial artery flow-mediated dilation (FMD) was evaluated. Subjects without COVID-19 were used as the control group.

RESULTS

There was no difference in age (64.7 ± 7.5 years vs. 61.2 ± 11.1 years vs. 62.4 ± 9.5, p = 0.28), male sex (49% vs. 60% vs. 52%, p = 0.71), control subjects, vaccinated, and unvaccinated subjects with COVID-19, respectively. Of the patients with COVID-19, 44% were vaccinated against SARS-CoV-2. Unvaccinated COVID-19 patients had significantly impaired FMD compared to vaccinated COVID-19 patients and Control subjects (2.05 ± 2.41 % vs. 7.24 ± 2.52% vs. 7.36 ± 2.94 %, p <0.001). Importantly, post hoc tests revealed that unvaccinated COVID-19 patients had significantly impaired FMD from both Vaccinated COVID-19 subjects (p <0.001) and from Control subjects (p <0.001). There was no difference in FMD between the control group and the vaccinated COVID-19 group (p = 0.99).

CONCLUSION

Hospitalized patients with COVID-19 present endothelial dysfunction in the acute phase of the disease. Endothelial function in unvaccinated patients with COVID-19 is impaired compared to control subjects as well compared to vaccinated patients with COVID-19. Vaccinated hospitalized subjects with COVID-19 do not show endothelial dysfunction, strengthening the protective role of vaccination against SARS-CoV-2.

Lower brachial artery flow-mediated dilation is associated with a worse prognosis and more lung parenchymal involvement in Covid-19: Prospective observational study

Severe acute respiratory syndrome coronavirus-2 is a highly infectious pathogenic coronavirus, which has appeared toward the end of 2019. The virus seen all over the world caused a pandemic of an acute respiratory disease named coronavirus disease 2019 (Covid-19). It has been shown that the virus that uses angiotensin-converting enzyme 2 receptors is causing endothelial dysfunction resulting in vascular inflammation and coagulopathy. It is possible to assess endothelial dysfunction by the flow-mediated dilatation (FMD) technique. Our study aimed to demonstrate the effect of endothelial dysfunction assessed using the FMD on prognosis and mortality in the patients hospitalized with the diagnosis of Covid-19. In this prospective observational study, endothelial functions of 94 patients hospitalized due to the Covid-19 in the ward or intensive care unit (ICU) were evaluated by FMD. The relationship among endothelial dysfunction and prognosis of disease, biochemical parameters, lung involvement, and mortality was investigated. We found that the FMD% values of the Covid-19 ICU patients compared to those followed up in the ward (2.66 ± 0.62 vs. 5.23 ± 1.46/P < .001) and those who died due to Covid-19 compared to those who were discharged alive (2.57 ± 0.22 vs. 4.66 ± 1.7/P < .001) were significantly lower. There were moderate negative correlation between FMD% and peak values of D-dimer (r = -0.52, P < .001), troponin (r = -0.45, P < .001), ferritin (r = -0.47, P < .001), lactate dehydrogenase (r = -0.49, P < .001), and white blood cells count (r = -0.23, P = .024). Lower FMD% was associated with higher lung parenchymal involvement (P < .001). The optimum cutoff point of FMD in predicting mortality was found to be 3.135% (sensitivity: 1, selectivity: 0.70). According to our results, lower FMD% was associated with higher lung parenchyma involvement, ICU admission, and mortality rate in Covid-19 patients. The best cutoff point for predicting mortality of FMD was 3.135%. Nevertheless, largescale, multicenter studies are needed to evaluate lower FMD values as a risk factor for mortality in Covid-19.

Hospital length of stay for COVID-19 patients: A systematic review and meta-analysis

The length of stay in the hospital for COVID-19 can aid in understanding the disease's prognosis. Thus, the goal of this study was to collectively estimate the hospital length of stay (LoS) in COVID-19 hospitalized individuals. To locate related studies, international databases (including Google Scholar, Science Direct, PubMed, and Scopus) were searched. The I² index, the Cochran Q test, and T² were used to analyze study heterogeneity. The mean LoS in COVID- 19 hospitalized patients was estimated using a random-effects model. COVID-19's total pooled estimated hospital LoS was 15.35, 95%CI:13.47-17.23; p<0.001, I² = 80.0). South America had the highest pooled estimated hospital LoS of COVID-19 among the continents, at 20.85 (95%CI: 14.80-26.91; p<0.001, I² = 0.01), whereas Africa had the lowest at 8.56 8 (95%CI: 1.00-22.76). The >60 age group had the highest pooled estimated COVID-19 hospital LoS of 16.60 (95%CI: 12.94-20.25; p<0.001, I² = 82.6), while the 40 age group had the lowest hospital LoS of 10.15 (95% CI: 4.90-15.39, p<0.001, I² = 22.1). The metanalysis revealed that COVID-19's hospital LoS was more than 10 days. However, it appears that this duration varies depending on a number of factors, including the patient's age and the availability of resources.

ERS International Congress 2021: highlights from the Respiratory Clinical Care and Physiology Assembly

It is a challenge to keep abreast of all the clinical and scientific advances in the field of respiratory medicine. This article contains an overview of laboratory-based science, randomised controlled trials and qualitative research that were presented during the 2021 European Respiratory Society International Congress within the sessions from the five groups of the Assembly 1 - Respiratory clinical care and physiology. Selected presentations are summarised from a wide range of topics: clinical problems, rehabilitation and chronic care, general practice and primary care, electronic/mobile health (e-health/m-health), clinical respiratory physiology, exercise and functional imaging.

Long-term cardio-vascular risk assessment in chronic kidney disease and kidney transplanted patients following SARS-COV-2 disease: protocol for multi-center observational match controlled trial

BACKGROUND

The coronavirus disease (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) produced a pandemic since March 2020 by affecting more than 243 million people with more than 5 million deaths globally. SARS-CoV-2 infection is produced by binding to angiotensin-converting enzyme, which among other sites is highly expressed in the endothelial cells of the blood vessels, pericytes and the heart, as well as in renal podocytes and proximal tubular epithelial cells. SARS-CoV-2 and cardiovascular disease (CVD) are interconnected by risk factors association with an increased incidence of the disease and by determining de novo cardiac complications. At the same time, COVID-19 disease can lead to acute kidney injury directly, or due to sepsis, multi-organ failure and shock. Therefore, the pre-existence of both CVD and chronic kidney disease (CKD) is linked with a higher risk of severe disease and worse prognosis.

METHODS

The main aim of this study is to assess the CV risk in a CKD (stage 3 to 5), dialysis and kidney transplanted population, following SARS-CoV-2 infection, with focus on the endothelial dysfunction as compared to a control group of matched patients. By using clinical evaluation, flow-mediated dilatation, carotid-femoral pulse wave velocity, intima-media thickness, echocardiographic parameters, lung ultrasound, bioimpedance spectroscopy and a series of novel biomarkers, the investigators will determine the long-term impact of this disease on CV and renal outcomes.

DISCUSSION

This study will address the challenges and implications in long-term CV sequeale of COVID-19 and focus on a better understanding of the underlying mechanisms and possible therapeutic options.

TRIAL REGISTRATION

Patient enrolment in the trial started in January 2021 and is expected to finish at the end of 2022. The study can be found on ClinicalTrials.gov database with NCT05125913 identifier. Registered on 18 November 2021 - Retrospectively registered.

Carotid intima-media thickness and flow-mediated dilation do not predict acute in-hospital outcomes in hospitalized patients with COVID-19

Studies have suggested a potential role of endothelial dysfunction and atherosclerosis in the pathophysiology of COVID-19. Herein we tested whether brachial flow-mediated dilation (FMD) and carotid intima-media thickness (cIMT) measured upon hospital admission are associated with acute in-hospital outcomes in hospitalized COVID-19 patients. A total of 211 hospitalized patients with COVID-19 were submitted to assessments of FMD and mean and maximum cIMT (cIMT_mean and cIMT_max) within the first 72 hours of hospital admission. Study primary outcome was a composite of intensive care unit admission, mechanical ventilation, or death during the hospitalization. These outcomes were also considered independently. Thrombotic events were included as a secondary outcome. Odds ratios (OR) and confidence intervals (CI) were calculated using unadjusted and adjusted multivariable logistic regression models. Eighty-eight (42%) participants demonstrated at least one of the composite outcomes. cIMT_mean and cIMT_max were predictors of mortality and thrombotic events in the univariate analysis (cIMT_mean and mortality: unadjusted OR 13.0[95%CI 1.7-105], P=0.015; cIMT_mean and thrombotic events: unadjusted OR 13.0[95%CI 1.7-93]; P=0.013; cIMT_max and mortality: unadjusted OR 8.3[95%CI 1.3-53]; P=0.026; cIMT_max and thrombotic events: unadjusted OR 12.0[95%CI 2.0-74]; P=0.007). However, these associations were no longer present after adjustment for potential confounders (P=0.06-0.79). Additionally, FMD% was not associated with any outcome. In conclusion, cIMT and FMD are not independent predictors of clinical outcomes in hospitalized patients with COVID-19. These results suggest that subclinical atherosclerosis and endothelial dysfunction may not be the main drivers of COVID-19 complications in hospitalized COVID-19 patients.

Endothelial dysfunction in acute and long standing COVID−19: A prospective cohort study

Background

Coronavirus disease-19 (COVID-19) is implicated by active endotheliitis, and cardiovascular morbidity. The long-COVID-19 syndrome implications in atherosclerosis have not been elucidated yet. We assessed the immediate, intermediate, and long-term effects of COVID-19 on endothelial function.

Methods

In this prospective cohort study, patients hospitalized for COVID-19 at the medical ward or Intensive Care Unit (ICU) were enrolled and followed up to 6 months post-hospital discharge. Medical history and laboratory examinations were performed while the endothelial function was assessed by brachial artery flow-mediated dilation (FMD). Comparison with propensity score-matched cohort (control group) was performed at the acute (upon hospital admission) and follow-up (1 and 6 months) stages.

Results

Seventy-three patients diagnosed with COVID-19 (37% admitted in ICU) were recruited. FMD was significantly (p < 0.001) impaired in the COVID-19 group (1.65 ± 2.31%) compared to the control (6.51 ± 2.91%). ICU-treated subjects presented significantly impaired (p = 0.001) FMD (0.48 ± 1.01%) compared to those treated in the medical ward (2.33 ± 2.57%). During hospitalization, FMD was inversely associated with Interleukin-6 and Troponin I (p < 0.05 for all). Although, a significant improvement in FMD was noted during the follow-up (acute: 1.75 ± 2.19% vs. 1 month: 4.23 ± 2.02%, vs. 6 months: 5.24 ± 1.62%; p = 0.001), FMD remained impaired compared to control (6.48 ± 3.08%) at 1 month (p < 0.001) and 6 months (p = 0.01) post-hospital discharge.

Conclusion

COVID-19 patients develop a notable endothelial dysfunction, which is progressively improved over a 6-month follow-up but remains impaired compared to healthy controls subjects. Whether chronic dysregulation of endothelial function following COVID-19 could be accompanied by a residual risk for cardiovascular and thrombotic events merits further research.

Persistent Endothelial Dysfunction in Coronavirus Disease-2019 Survivors Late After Recovery

Background

Coronavirus disease 2019 (COVID-19) can result in an endothelial dysfunction in acute phase. However, information on the late vascular consequences of COVID-19 is limited.

Methods

Brachial artery flow-mediated dilation (FMD) examination were performed, and inflammatory biomarkers were assessed in 86 survivors of COVID-19 for 327 days (IQR 318–337 days) after recovery. Comparisons were made with 28 age-matched and sex-matched healthy controls and 30 risk factor-matched patients.

Results

Brachial artery FMD was significantly lower in the survivors of COVID-19 than in the healthy controls and risk factor-matched controls [median (IQR) 7.7 (5.1–10.7)% for healthy controls, 6.9 (5.5–9.4)% for risk factor-matched controls, and 3.5(2.2–4.6)% for COVID-19, respectively, p < 0.001]. The FMD was lower in 25 patients with elevated tumor necrosis factor (TNF)-α [2.7(1.2–3.9)] than in 61 patients without elevated TNF-α [3.8(2.6–5.3), p = 0.012]. Furthermore, FMD was inversely correlated with serum concentration of TNF-α (r = −0.237, p = 0.007).

Conclusion

Survivors of COVID-19 have a reduced brachial artery FMD, which is inversely correlated with increased serum concentration of TNF-α. Prospective studies on the association of endothelial dysfunction with long-term cardiovascular outcomes, especially the early onset of atherosclerosis, are warranted in survivors of COVID-19.

Low Brachial Artery Flow-Mediated Dilation Predicts Worse Prognosis in Hospitalized Patients with COVID-19

Background: Endothelial injury can be induced by coronavirus disease 2019 (COVID-19) and seems to exert a crucial pathogenic role in its most severe clinical manifestations. We aimed to investigate the association between brachial artery flow-mediated dilation (bFMD), a potential clinical and non-invasive measure of endothelial function, and in-hospital prognosis of COVID-19 patients. Methods: Brachial artery flow-mediated dilation was assessed in hospitalized COVID-19 patients within 48 h of hospital admission. The association between bFMD and either intensive care unit (ICU) admission or in-hospital death was explored using univariable and multivariable analyses. Results: Four hundred and eight patients were enrolled. Significantly lower bFMD values emerged in COVID-19 patients with either radiographic signs of pneumonia, respiratory distress, or the need for non-invasive ventilation compared with patients without these signs (p < 0.001, p = 0.001, and p < 0.001, respectively). Forty-two (10%) patients were admitted to the ICU, 76 (19%) patients died, and 118 (29%) patients met the composite endpoint of ICU admission/in-hospital death. At unadjusted Cox regression analysis showed that low bFMD (<4.4%, the median value) was associated with a higher risk for the composite endpoint of ICU admission/in-hospital death compared with high bFMD (≥4.4%, the median value) (HR 1.675, 95% CI 1.155–2.428, p = 0.007). Multi-adjusted Cox regression analyses showed that low bFMD was independently associated with a 1.519- to 1.658-fold increased risk for the composite endpoint of ICU admission/in-hospital death. Conclusions: Low bFMD predicts an unfavorable in-hospital prognosis in COVID-19 patients. The measurement of bFMD may be clinically useful in the prognostic stratification of COVID-19 patients upon hospital admission.

Persistent Endothelial Dysfunction in Post-Acute COVID-19 Syndrome: A Case-Control Study

Background: Endothelial dysfunction has a key role in the pathogenesis of coronavirus disease 2019 (COVID-19) and its disabling complications. We designed a case-control study to assess the alterations of endothelium-dependent flow-mediated dilation (FMD) among convalescent COVID-19 patients. Methods: COVID-19 patients referred to a Pulmonary Rehabilitation Unit within 2 months from swab test negativization were consecutively evaluated for inclusion and compared to controls matched for age, gender, and cardiovascular risk factors. Results: A total of 133 convalescent COVID-19 patients (81.2% males, mean age 61.6 years) and 133 matched controls (80.5% males, mean age 60.4 years) were included. A significantly lower FMD was documented in convalescent COVID-19 patients as compared to controls (3.2% ± 2.6 vs. 6.4% ± 4.1 p < 0.001), confirmed when stratifying the study population according to age and major clinical variables. Among cases, females exhibited significantly higher FMD values as compared to males (6.1% ± 2.9 vs. 2.5% ± 1.9, p < 0.001). Thus, no significant difference was observed between cases and controls in the subgroup analysis on females (6.1% ± 2.9 vs. 5.3% ± 3.4, p = 0.362). Among convalescent COVID-19 patients, FMD showed a direct correlation with arterial oxygen tension (rho = 0.247, p = 0.004), forced expiratory volume in 1 s (rho = 0.436, p < 0.001), forced vital capacity (rho = 0.406, p < 0.001), and diffusing capacity for carbon monoxide (rho = 0.280, p = 0.008). Overall, after adjusting for major confounders, a recent COVID-19 was a major and independent predictor of FMD values (β = −0.427, p < 0.001). Conclusions: Post-acute COVID-19 syndrome is associated with a persistent and sex-biased endothelial dysfunction, directly correlated with the severity of pulmonary impairment.