Tag: long covid pathophysiology

Sonographic Diaphragm Abnormalities are an Unexpectedly Frequent Feature of Long COVID Outpatients with Unexplained Dyspnea and Fatigue

Abstract:

Purpose: The primary aim of this study is to define the sonographic diaphragm phenotype of Long COVID rehabilitation outpatients with non-specific dyspnea and fatigue. We analyzed patients referred from a pulmonary post-COVID clinic that were lacking a specific cardiopulmonary diagnosis for their symptoms. Additionally, we report the functional outcomes of subset of patients who completed an outpatient cardiopulmonary physical therapy program.

Methods: This was a retrospective cohort study (n = 58) of consecutive patients referred for neuromuscular ultrasound assessment of diaphragm muscle using B-mode technique. Patients were recruited from a single academic hospital between February 25, 2021 and November 22, 2022.

Results: Sonographic abnormalities were identified in 57% (33/58) of patients, and in the vast majority of cases (33/33) was defined by a low diaphragm muscle thickness. Thinner diaphragm muscles are correlated with lower serum creatinine and creatine kinase values, but there was no association with markers of systemic inflammation. Thirty three patients participated in outpatient cardiopulmonary physical therapy that included respiratory muscle training, and 75.8% (25/33) had documented improvement.

Conclusion: In the outpatient rehabilitation setting, patients with Long COVID display low diaphragm muscle thickness, but intact muscle contractility, with surprising frequency on neuromuscular ultrasound. We speculate this represents a form of disuse atrophy. Also, these patients appear to have a favorable response to cardiopulmonary physical therapy that includes respiratory muscle training.

Source: Prabhav P. Deo, Joseph I. Bailey, Alexandra S. Jensen, Ellen Farr, Meghan Fahey, Matthew Isherwood, Keerthana Chakka, Lisa F. Wolfe, Ishan Roy, Marc A. Sala, Colin K. Franz. Sonographic Diaphragm Abnormalities are an Unexpectedly Frequent Feature of Long COVID Outpatients with Unexplained Dyspnea and Fatigue. medRxiv 2022.06.29.22277054; doi: https://doi.org/10.1101/2022.06.29.22277054 (Full text)

Thromboembolism in the Complications of Long COVID-19

Abstract:

SARS-CoV-2 is a +ssRNA helical coronavirus responsible for the global pandemic caused by coronavirus disease 19 (COVID-19). Classical clinical symptoms from primary COVID-19 when symptomatic include cough, fever, pneumonia or even ARDS; however, they are limited primarily to the respiratory system. Long-COVID-19 sequalae is responsible for many pathologies in almost every organ system and may be present in up to 30% of patients who have developed COVID-19.

Our review focuses on how long-COVID-19 (3 -24 weeks after primary symptoms) may lead to an increased risk for stroke and thromboembolism. Patients who were found to be primarily at risk for thrombotic events included critically ill and immunocompromised patients. Additional risk factors for thromboembolism and stroke included diabetes, hypertension, respiratory and cardiovascular disease, and obesity.

The etiology of how long-COVID-19 leads to a hypercoagulable state are yet to be definitively elucidated. However, anti-phospholipid antibodies and elevated D-dimer are present in many patients who develop thromboembolism. In addition, chronic upregulation and exhaustion of the immune system may lead to a pro-inflammatory and hypercoagulable state, increasing the likelihood for induction of thromboembolism or stroke. ‘

This article provides an up-to-date review on the proposed etiologies for thromboembolism and stroke in patients with long-COVID-19 and to assist health care providers in examining patients who may be at a higher risk for developing these pathologies.

Source: Leilani A Lopes, Devendra K Agrawal. Thromboembolism in the Complications of Long COVID-19. Cardiology and Cardiovascular
Medicine. 7 (2023): 123-128. https://fortunepublish.com/articles/10.26502.fccm.92920317.pdf (Full text)

Reduced exercise capacity, chronotropic incompetence, and early systemic inflammation in cardiopulmonary phenotype Long COVID

Abstract:

Background: Mechanisms underlying persistent cardiopulmonary symptoms following SARS-CoV-2 infection (post-acute sequelae of COVID-19 “PASC” or “Long COVID”) remain unclear. This study sought to elucidate mechanisms of cardiopulmonary symptoms and reduced exercise capacity.

Methods: We conducted cardiopulmonary exercise testing (CPET), cardiac magnetic resonance imaging (CMR) and ambulatory rhythm monitoring among adults > 1 year after confirmed SARS-CoV-2 infection in a post-COVID cohort, compared those with or without symptoms, and correlated findings with previously measured biomarkers.

Results: Sixty participants (median age 53, 42% female, 87% non-hospitalized) were studied at median 17.6 months following SARS-CoV-2 infection. On CPET, 18/37 (49%) with symptoms had reduced exercise capacity (<85% predicted) compared to 3/19 (16%) without symptoms (p = 0.02). Adjusted peak VO2 was 5.2 ml/kg/min lower (95%CI 2.1-8.3; p = 0.001) or 16.9% lower percent predicted (95%CI 4.3-29.6; p = 0.02) among those with symptoms. Chronotropic incompetence was common. Inflammatory markers and antibody levels early in PASC were negatively correlated with peak VO2 more than 1 year later. Late-gadolinium enhancement on CMR and arrhythmias were absent.

Conclusions: Cardiopulmonary symptoms >1 year following COVID-19 were associated with reduced exercise capacity, which was associated with elevated inflammatory markers early in PASC. Chronotropic incompetence may explain exercise intolerance among some with cardiopulmonary Long COVID.

Source: Durstenfeld MS, Peluso MJ, Kaveti P, Hill C, Li D, Sander E, Swaminathan S, Arechiga VM, Lu S, Goldberg SA, Hoh R, Chenna A, Yee BC, Winslow JW, Petropoulos CJ, Kelly JD, Glidden DV, Henrich TJ, Martin JN, Lee YJ, Aras MA, Long CS, Grandis DJ, Deeks SG, Hsue PY. Reduced exercise capacity, chronotropic incompetence, and early systemic inflammation in cardiopulmonary phenotype Long COVID. J Infect Dis. 2023 May 11:jiad131. doi: 10.1093/infdis/jiad131. Epub ahead of print. PMID: 37166076. https://academic.oup.com/jid/advance-article/doi/10.1093/infdis/jiad131/7159960 (Full text available as PDF file)

Pulmonary circulation abnormalities in post-acute COVID-19 syndrome: dual-energy CT angiographic findings in 79 patients

Abstract:

Objectives: To evaluate the frequency and pattern of pulmonary vascular abnormalities in the year following COVID-19.

Methods: The study population included 79 patients remaining symptomatic more than 6 months after hospitalization for SARS-CoV-2 pneumonia who had been evaluated with dual-energy CT angiography.

Results: Morphologic images showed CT features of (a) acute (2/79; 2.5%) and focal chronic (4/79; 5%) PE; and (b) residual post COVID-19 lung infiltration (67/79; 85%). Lung perfusion was abnormal in 69 patients (87.4%). Perfusion abnormalities included (a) perfusion defects of 3 types: patchy defects (n = 60; 76%); areas of non-systematized hypoperfusion (n = 27; 34.2%); and/or PE-type defects (n = 14; 17.7%) seen with (2/14) and without (12/14) endoluminal filling defects; and (b) areas of increased perfusion in 59 patients (74.9%), superimposed on ground-glass opacities (58/59) and vascular tree-in-bud (5/59). PFTs were available in 10 patients with normal perfusion and in 55 patients with abnormal perfusion. The mean values of functional variables did not differ between the two subgroups with a trend toward lower DLCO in patients with abnormal perfusion (74.8 ± 16.7% vs 85.0 ± 8.1).

Conclusion: Delayed follow-up showed CT features of acute and chronic PE but also two types of perfusion abnormalities suggestive of persistent hypercoagulability as well as unresolved/sequelae of microangiopathy.

Clinical relevance statement: Despite dramatic resolution of lung abnormalities seen during the acute phase of the disease, acute pulmonary embolism and alterations at the level of lung microcirculation can be identified in patients remaining symptomatic in the year following COVID-19.

Key points: • This study demonstrates newly developed proximal acute PE/thrombosis in the year following SARS-CoV-2 pneumonia. • Dual-energy CT lung perfusion identified perfusion defects and areas of increased iodine uptake abnormalities, suggestive of unresolved damage to lung microcirculation. • This study suggests a complementarity between HRCT and spectral imaging for proper understanding of post COVID-19 lung sequelae.

Source: Mohamed I, de Broucker V, Duhamel A, Giordano J, Ego A, Fonne N, Chenivesse C, Remy J, Remy-Jardin M. Pulmonary circulation abnormalities in post-acute COVID-19 syndrome: dual-energy CT angiographic findings in 79 patients. Eur Radiol. 2023 Apr 25:1–13. doi: 10.1007/s00330-023-09618-9. Epub ahead of print. PMID: 37145145; PMCID: PMC10129318. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10129318/ (Full text)

Post-acute Sequelae of SARS Co-V2 and Chronic Fatigue/Myalgic Encephalitis Share Similar Pathophysiologic Mechanisms of Exercise Limitation

Abstract:

Abstract available online: https://www.atsjournals.org/doi/abs/10.1164/ajrccm-conference.2023.207.1_MeetingAbstracts.A6470

Source: S. Jothi, G. Claessen, M. Insel, S. Kubba, E. Howden, S.-R. Carmona, F.P. Rischard. Post-acute Sequelae of SARS Co-V2 and Chronic Fatigue/Myalgic Encephalitis Share Similar Pathophysiologic Mechanisms of Exercise Limitation. https://www.atsjournals.org/doi/abs/10.1164/ajrccm-conference.2023.207.1_MeetingAbstracts.A6470

Netosis -A double-edged sword in the Pathogenesis of LONG COVID

Abstract:

The emergence of COVID-19 as a global pandemic has had far-reaching effects on the health of individuals worldwide. Although there has been a decrease in the severity of the disease, there is a growing concern about the long-term impact of COVID-19 on the health of individuals, particularly cardiovascular complications, known as Long-COVID, which can significantly increase morbidity and mortality rates in people recovering from COVID-19 in the recent past.
The severity of COVID-19 has been linked to various factors, including the role of neutrophils and neutrophil extracellular traps (NET). These extracellular webs, composed of chromatin, microbicidal proteins, and oxidant enzymes, are released by neutrophils to fight infections. However, if not properly regulated, NETs can lead to thrombo-inflammatory states and microangiopathy in the body, resulting in complications such as sepsis, thrombosis, and respiratory failure.
Understanding the detailed pathophysiology and association of NETs with the prognosis of COVID-19 infection is crucial for future implications and management. The purpose of this review is to analyze the potential contribution of NETosis in the pathophysiology of COVID-19 and its subsequent complications apart from its beneficial effect. This may provide insight into potential therapeutic interventions for COVID-19 patients.
Source: Durre Aden, vagisha sharma, sufian zaheer, et al. Netosis -A double-edged sword in the Pathogenesis of LONG COVID. Authorea. April 28, 2023. https://www.authorea.com/users/570888/articles/640398-netosis-a-double-edged-sword-in-the-pathogenesis-of-long-covid (Full text available as PDF file)

Damage to endothelial barriers and its contribution to long COVID

Abstract:

The world continues to contend with COVID-19, fueled by the emergence of viral variants. At the same time, a subset of convalescent individuals continues to experience persistent and prolonged sequelae, known as long COVID. Clinical, autopsy, animal and in vitro studies all reveal endothelial injury in acute COVID-19 and convalescent patients. Endothelial dysfunction is now recognized as a central factor in COVID-19 progression and long COVID development.

Different organs contain different types of endothelia, each with specific features, forming different endothelial barriers and executing different physiological functions. Endothelial injury results in contraction of cell margins (increased permeability), shedding of glycocalyx, extension of phosphatidylserine-rich filopods, and barrier damage.

During acute SARS-CoV-2 infection, damaged endothelial cells promote diffuse microthrombi and destroy the endothelial (including blood-air, blood-brain, glomerular filtration and intestinal-blood) barriers, leading to multiple organ dysfunction. During the convalescence period, a subset of patients is unable to fully recover due to persistent endothelial dysfunction, contributing to long COVID. There is still an important knowledge gap between endothelial barrier damage in different organs and COVID-19 sequelae. In this article, we mainly focus on these endothelial barriers and their contribution to long COVID.

Source: Wu X, Xiang M, Jing H, Wang C, Novakovic VA, Shi J. Damage to endothelial barriers and its contribution to long COVID. Angiogenesis. 2023 Apr 27:1–18. doi: 10.1007/s10456-023-09878-5. Epub ahead of print. PMID: 37103631; PMCID: PMC10134732. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10134732/ (Full text)

A Post-Pandemic Enigma: The Cardiovascular Impact of Post-Acute Sequelae of SARS-CoV-2

Abstract:

COVID-19 has become the first modern-day pandemic of historic proportion, affecting >600 million individuals worldwide and causing >6.5 million deaths. While acute infection has had devastating consequences, postacute sequelae of SARS-CoV-2 infection appears to be a pandemic of its own, impacting up to one-third of survivors and often causing symptoms suggestive of cardiovascular phenomena. This review will highlight the suspected pathophysiology of postacute sequelae of SARS-CoV-2, its influence on the cardiovascular system, and potential treatment strategies.

Source: Singh TK, Zidar DA, McCrae K, Highland KB, Englund K, Cameron SJ, Chung MK. A Post-Pandemic Enigma: The Cardiovascular Impact of Post-Acute Sequelae of SARS-CoV-2. Circ Res. 2023 May 12;132(10):1358-1373. doi: 10.1161/CIRCRESAHA.122.322228. Epub 2023 May 11. PMID: 37167358; PMCID: PMC10171306. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10171306/ (Full text)

The fatal trajectory of pulmonary COVID-19 is driven by lobular ischemia and fibrotic remodelling

Abstract:

Background: COVID-19 is characterized by a heterogeneous clinical presentation, ranging from mild symptoms to severe courses of disease. 9-20% of hospitalized patients with severe lung disease die from COVID-19 and a substantial number of survivors develop long-COVID. Our objective was to provide comprehensive insights into the pathophysiology of severe COVID-19 and to identify liquid biomarkers for disease severity and therapy response.

Methods: We studied a total of 85 lungs (n = 31 COVID autopsy samples; n = 7 influenza A autopsy samples; n = 18 interstitial lung disease explants; n = 24 healthy controls) using the highest resolution Synchrotron radiation-based hierarchical phase-contrast tomography, scanning electron microscopy of microvascular corrosion casts, immunohistochemistry, matrix-assisted laser desorption ionization mass spectrometry imaging, and analysis of mRNA expression and biological pathways. Plasma samples from all disease groups were used for liquid biomarker determination using ELISA. The anatomic/molecular data were analyzed as a function of patients’ hospitalization time.

Findings: The observed patchy/mosaic appearance of COVID-19 in conventional lung imaging resulted from microvascular occlusion and secondary lobular ischemia. The length of hospitalization was associated with increased intussusceptive angiogenesis. This was associated with enhanced angiogenic, and fibrotic gene expression demonstrated by molecular profiling and metabolomic analysis. Increased plasma fibrosis markers correlated with their pulmonary tissue transcript levels and predicted disease severity. Plasma analysis confirmed distinct fibrosis biomarkers (TSP2, GDF15, IGFBP7, Pro-C3) that predicted the fatal trajectory in COVID-19.

Interpretation: Pulmonary severe COVID-19 is a consequence of secondary lobular microischemia and fibrotic remodelling, resulting in a distinctive form of fibrotic interstitial lung disease that contributes to long-COVID.

Source: Ackermann M, Kamp JC, Werlein C, Walsh CL, Stark H, Prade V, Surabattula R, Wagner WL, Disney C, Bodey AJ, Illig T, Leeming DJ, Karsdal MA, Tzankov A, Boor P, Kühnel MP, Länger FP, Verleden SE, Kvasnicka HM, Kreipe HH, Haverich A, Black SM, Walch A, Tafforeau P, Lee PD, Hoeper MM, Welte T, Seeliger B, David S, Schuppan D, Mentzer SJ, Jonigk DD. The fatal trajectory of pulmonary COVID-19 is driven by lobular ischemia and fibrotic remodelling. EBioMedicine. 2022 Nov;85:104296. doi: 10.1016/j.ebiom.2022.104296. Epub 2022 Oct 4. PMID: 36206625; PMCID: PMC9535314. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9535314/ (Full text)

Lung diffusing capacities for nitric oxide and carbon monoxide at rest and post-walking in long COVID

Abstract:

Background: Approximately one-third of long coronavirus disease 2019 (long COVID) patients report breathlessness and fatigue even during activities of daily living. We hypothesised that abnormalities of combined diffusing capacity of the lung for nitric oxide (D LNO) and carbon monoxide (D LCO) at rest or after mild exercise are associated with breathlessness in patients with long COVID.

Methods: Single-breath combined D LNO and D LCO were measured at rest and immediately after a short bout of treadmill exercise simulating ordinary walking in 32 Caucasian patients with long COVID and dyspnoea at rest. 20 subjects served as a control group.

Results: At rest, combined D LNO, D LCO and alveolar volume (V A) were significantly lower in long COVID than in controls, with D LNO and D LCO being below the limits of normal in 69% and 41% of cases, respectively. Mean values of D LNO/V A and D LCO/V A in long COVID patients were less than controls, yet, in only 22% and 12% of long COVID patients were the values of D LNO/V A and D LCO/V A below the limits of normal. After treadmill exercise, D LNO, D LNO/D LCO, V A and heart rate increased significantly without differences between groups. D LNO remained below the limit of normal in 47% of long COVID patients.

Conclusion: These data suggest localised discrete loss of lung units in approximately half of long COVID patients, not completely explained by loss of V A or of alveolar-capillary recruitment during exercise.

Source: Barisione G, Brusasco V. Lung diffusing capacities for nitric oxide and carbon monoxide at rest and post-walking in long COVID. ERJ Open Res. 2023 Apr 17;9(2):00363-2022. doi: 10.1183/23120541.00363-2022. PMID: 37070120; PMCID: PMC9638122. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9638122/ (Full text)