Tracking peripheral vascular function for six months in young adults following SARS-CoV-2 infection.

SARS-CoV-2 infection is known to instigate a range of physiologic perturbations, including vascular dysfunction. However, little work has concluded how long these effects may last, especially among young adults with mild symptoms. To determine potential recovery from acute vascular dysfunction in young adults (8 M/8F, 21 ± 1 yr, 23.5 ± 3.1 kg⋅m-2 ), we longitudinally tracked brachial artery flow-mediated dilation (FMD) and reactive hyperemia (RH) in the arm and hyperemic response to passive limb movement (PLM) in the leg, with Doppler ultrasound, as well as circulating biomarkers of inflammation (interleukin-6, C-reactive protein), oxidative stress (thiobarbituric acid reactive substances, protein carbonyl), antioxidant capacity (superoxide dismutase), and nitric oxide bioavailability (nitrite) monthly for a 6-month period post-SARS-CoV-2 infection. FMD, as a marker of macrovascular function, improved from month 1 (3.06 ± 1.39%) to month 6 (6.60 ± 2.07%; p < 0.001). FMD/Shear improved from month one (0.10 ± 0.06 AU) to month six (0.18 ± 0.70 AU; p = 0.002). RH in the arm and PLM in the leg, as markers of microvascular function, did not change during the 6 months (p > 0.05). Circulating markers of inflammation, oxidative stress, antioxidant capacity, and nitric oxide bioavailability did not change during the 6 months (p > 0.05). Together, these results suggest some improvements in macrovascular, but not microvascular function, over 6 months following SARS-CoV-2 infection. The data also suggest persistent ramifications for cardiovascular health among those recovering from mild illness and among young, otherwise healthy adults with SARS-CoV-2.

[Changes in ocular hemodynamics in patients recovered from COVID-19]. / Oftal'mogemodinamicheskie narusheniya posle perenesennoi koronavirusnoi infektsii, vyzvannoi virusom SARS-CoV-2.

PURPOSE: To evaluate the severity of hemodynamic changes in the ocular vessels of patients recovered from COVID-19. MATERIAL AND METHODS: The study included 44 patients (88 eyes) aged 28-60 years, among them 24 (54.5%) women and 20 (45.4%) men, with SARS-CoV-2 infection confirmed by PCR no more than 2 months prior to enrollment and with no ophthalmological complaints within 2 months before the disease, as well as 20 healthy volunteers (40 eyes). At the time of the study all patients had a negative PCR result for SARS-CoV-2. The patients were divided into 2 groups. The first group comprised 24 patients who did not take any anticoagulants during the treatment. The second group consisted of 20 patients who received anticoagulants (Rivaroxaban (Xarelto)) at a dosage of 10 mg per day for 1-1.5 months. The maximum systolic (Vs), end-diastolic (Vd) blood flow velocity, as well as resistance index (RI) in the ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were measured in all study patients with the ultrasound imaging system VOLUSON E8 Expert («Kretz¼, USA). Additionally, the flowmetry method was used to assess the volumetric ocular blood flow (VOBF) on Ocular Blood Flow Analyzer system («Paradigm Medical Industries, Inc.¼, USA). RESULTS: In the first group, a decrease in Vs and Vd was noted amid a significant increase of RI in CRA and SPCA, as well as an increase of RI in OA compared with the age-normal values (p<0.05). In the second group, a decrease in Vs and Vd was noted amid a significant increase of RI in CRA, as well as a decrease in Vs in SPCA and an increase of RI in OA relative to the age-normal values (p<0.05). A decrease in VOBF was noted in the first group in comparison to the second group and the age norm (p<0.05). CONCLUSION: Blood flow velocity parameters in the ocular vessels are reduced in patients recovered from COVID-19 compared to the age-normal values. There was a significant decrease in volumetric ocular blood flow parameters in COVID-19 patients who did not take any anticoagulants compared to the age-normal values. Anticoagulants intake has a positive impact on hemodynamic characteristics in the ocular vessels and volumetric ocular blood flow in patients with COVID-19.

Altered central and peripheral haemodynamics during rhythmic handgrip exercise in young adults with SARS-CoV-2.

NEW FINDINGS: What is the central question of this study? Are central and peripheral haemodynamics during handgrip exercise different in young adults 3-4 weeks following infection with of SARS-CoV-2 compared with young healthy adults. What is the main finding and its importance? Exercising heart rate was higher while brachial artery blood flow and vascular conductance were lower in the SARS-CoV-2 compared with the control group. These findings provide evidence for peripheral impairments to exercise among adults with SARS-CoV-2, which may contribute to exercise limitations. ABSTRACT: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can have a profound impact on vascular function. While exercise intolerance may accompany a variety of symptoms associated with SARS-CoV-2 infection, the impact of SARS-CoV-2 on exercising blood flow (BF) remains unclear. Central (photoplethysmography) and peripheral (Doppler ultrasound) haemodynamics were determined at rest and during rhythmic handgrip (HG) exercise at 30% and 45% of maximal voluntary contraction (MVC) in young adults with mild symptoms 25 days after testing positive for SARS-CoV-2 (SARS-CoV-2: n = 8M/5F; age: 21 ± 2 years; height: 176 ± 11 cm; mass: 71 ± 11 kg) and were cross-sectionally compared with control subjects (Control: n = 8M/5F; age: 27 ± 6 years; height: 178 ± 8 cm; mass: 80 ± 25 kg). Systolic blood pressure, end systolic arterial pressure and rate pressure product were higher in the SARS-CoV-2 group during exercise at 45% MVC compared with controls. Brachial artery BF was lower in the SARS-CoV-2 group at both 30% MVC (Control: 384.8 ± 93.3 ml min-1 ; SARS-CoV-2: 307.8 ± 105.0 ml min-1 ; P = 0.041) and 45% MVC (Control: 507.4 ± 109.9 ml min-1 ; SARS-CoV-2: 386.3 ± 132.5 ml min-1 ; P = 0.002). Brachial artery vascular conductance was lower at both 30% MVC (Control: 3.93 ± 1.07 ml min-1  mmHg-1 ; SARS-CoV-2: 3.11 ± 0.98 ml min-1  mmHg-1 ; P = 0.022) and 45% MVC (Control: 4.74 ± 1.02 ml min-1  mmHg-1 ; SARS-CoV-2: 3.46 ± 1.10 ml min-1  mmHg-1 ; P < 0.001) in the SARS-CoV-2 group compared to control group. The shear-induced dilatation of the brachial artery increased similarly across exercise intensities in the two groups, suggesting the decrease in exercising BF may be due to microvascular impairments. Brachial artery BF is attenuated during HG exercise in young adults recently diagnosed with mild SARS-CoV-2, which may contribute to diminished exercise capacity among those recovering from SARS-CoV-2 like that seen in severe cases.

The short external rotators dissection during the posterior approach in total hip arthroplasty did not change the blood flow.

OBJECTIVES: The posterior approach in total hip arthroplasty (THA) often requires dissection of the short external rotators (SERs), which could increase the postoperative dislocation rate. The reattachment of the dissected SERs has been reported to reduce the dislocation rate, while such repair generally causes progression of muscle atrophy. 1 of the suggested causes of atrophy is reduced blood flow to the repaired SERs. The present study aimed to measure the blood flow of the SERs before dissection (pre-tenotomy) and after reattachment (post-reattachment) during the posterior approach in THA. METHODS: This prospective study included 26 patients who underwent THA via the posterior approach. A laser-Doppler rheometer was used to measure the blood flow in the following SERs at the time of pre-tenotomy and post-reattachment: the piriformis muscle (PM), superior gemellus (SG), inferior gemellus (IG), obturator internus (OI), and subcutaneous tissue as a control. RESULTS: The average pre-tenotomy and post-reattachment blood flows (mL/minutes/100 g) were: 1.90 ± 0.28 and 1.92 ± 0.40 in the PM, 1.94 ± 0.20 and 1.99 ± 0.39 in the SG, 1.91 ± 0.21 and 1.94 ± 0.30 in the IG, 1.93 ± 0.22 and 1.98 ± 0.36 in the OI, and 1.94 ± 0.24 and 1.87 ± 0.38 in the subcutaneous tissue. The pre-tenotomy and post-reattachment blood flows did not show significant difference in any muscle. CONCLUSIONS: Laser-Doppler blood flow measurements showed that the blood flow is preserved, even when the SERs are dissected and reattached in THA via the posterior approach.

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

BACKGROUND: The prothrombotic phenotype and diffuse intravascular coagulation observed in COVID-19 reflect endothelial dysfunction, which is linked to blood flow delivery deficiencies and cardiovascular risk. Assessments of detect vascular deficiencies among newly diagnosed and hospitalized patients due to COVID-19 have yet to be determined. OBJECTIVE: To assess endothelial function characteristics in relation to length of hospitalization and mortality in patients diagnosed with COVID-19 and compare to patients without COVID-19. METHODS: A prospective observational study involving 180 patients with confirmed COVID-19 (COVID-19 group) or suspected and ruled out COVID-19 (Non-COVID-19 group). Clinical evaluation and flow mediated vasodilation (FMD) were performed between the first 24-48 h of hospitalization. Patients were followed until death or discharge. RESULTS: We evaluated 98 patients (COVID-19 group) and 82 (Non-COVID-19 group), COVID-19 group remained hospitalized longer and more deaths occurred compared to the Non-COVID-19 group (p = 0.01; and p < 0.01). Patients in COVID-19 group also had a significantly greater reduction in both FMDmm and FMD% (p < 0.01 in both). We found that absolute FMD≤0.26 mm and relative FMD≤3.43% were the ideal cutoff point to predict mortality and longer hospital stay. In Kaplan Meyer's analysis patients had a high probability of death within a period of up to 10 days of hospitalization. CONCLUSION: Patients hospitalized for COVID-19 present endothelial vascular dysfunction early, remained hospitalized longer and had a higher number of deaths, when compared with patients without COVID-19.

Microvascular Dysfunction in Patients with Critical Covid-19, a Pilot Study.

BACKGROUND: Endothelial and microvascular dysfunction may be a key pathogenic feature of severe COVID-19. The aim of this study was to investigate endothelial-dependent and endothelial-independent skin microvascular reactivity in patients with critical COVID-19. METHODS: Twelve patients with COVID-19 treated with non-invasive or invasive mechanical ventilation were included in the study. We investigated skin microvascular reactivity on 2 separate days during hospitalization (study day 1 and 2) and at least 3 months after disease onset (study day 3). Twelve controls with no confirmed or suspected COVID-19 infection during 2020 were also examined. Skin perfusion was investigated through Laser Speckle Contrast Imaging before and after iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) to determine the endothelial-dependent and the endothelial-independent vasodilation, respectively. RESULTS: Compared to controls, patients with critical COVID-19 had higher basal skin perfusion and reduced responses to endothelial-dependent (ACh, P = 0.002) and endothelial-independent (SNP, P = 0.01) vasodilator drugs on study day 1. In addition, the ACh/SNP ratio was significantly reduced in patients (0.50 ±â€Š0.36 vs. 0.91 ±â€Š0.49 in controls, P = 0.02). Three months after disease onset, surviving patients tended to have reduced ACh-mediated vasodilation compared to controls (P = 0.08). CONCLUSIONS: This small-sized pilot study demonstrates that critical COVID-19 infection is associated with microvascular impairment and, in particular, a markedly reduced endothelial function. Our results also suggest that microvascular function may not be fully recovered 3 months after disease onset.

Critically Ill COVID-19 Patients With Acute Kidney Injury Have Reduced Renal Blood Flow and Perfusion Despite Preserved Cardiac Function: A Case-Control Study Using Contrast-Enhanced Ultrasound.

BACKGROUND: Acute kidney injury (AKI) is a common complication of COVID-19 critical illness but the pathophysiology is uncertain. Some evidence has indicated that a vascular aetiology may be implicated. We used contrast-enhanced ultrasound (CEUS) and echocardiography to study renal perfusion and global blood flow and compared our findings with measurements taken in a group of septic shock patients and healthy volunteers. METHODS: Prospective case-control study. Renal perfusion variables were assessed with CEUS; macrovascular blood flow was assessed using Doppler analysis of large renal vessels; echocardiography was used to assess right and left heart function and cardiac output. RESULTS: CEUS-derived parameters were reduced in COVID-19 associated AKI compared with healthy controls (perfusion index 3,415 vs. 548 a.u., P = 0·001; renal blood volume 7,794 vs. 3,338 a.u., P = 0·04). Renal arterial flow quantified using time averaged peak velocity was also reduced compared with healthy controls (36·6 cm/s vs. 20·9 cm/s, P = 0.004) despite cardiac index being similar between groups (2.8 L/min/m2 vs. 3.7 L/min/m2, P = 0.07). There were no differences in CEUS-derived or cardiac parameters between COVID-19 and septic shock patients but patients with septic shock had more heterogeneous perfusion variables. CONCLUSION: Both large and small vessel blood flow is reduced in patients with COVID-19 associated AKI compared with healthy controls, which does not appear to be a consequence of right or left heart dysfunction. A reno-vascular pathogenesis of COVID-19 AKI seems likely.