Persistent dyspnea after COVID-19 is not related to cardiopulmonary impairment; a cross-sectional study of persistently dyspneic COVID-19, non-dyspneic COVID-19 and controls

Longitudinal assessment of lung function in patients following COVID-19

BACKGROUND

While effects of COVID-19 on lung function are commonly described in those with severe illness, less is known about those with less severe illness, and most studies do not extend beyond 6 months following initial presentation.

RESEARCH QUESTION

What are the effects of COVID-19 on lung function in a cohort of participants that included those with more severe and less severe disease over a 1 year period from time of enrollment?

STUDY DESIGN

We enrolled 52 participants who included those with more severe (had been hospitalized) and less severe (not hospitalized) illness and measured spirometry, lung volumes, diffusing capacity, oscillometry, maximal muscle pressures, inspiratory drive, exercise capacity, and symptom and quality of life surveys at presentation, and repeated the measurements 6 and 12 months later.

RESULTS

While participants who had been hospitalized had consistently lower lung function in all measures, all values were within normal reference ranges. The pattern of lung function change suggested a predominant restrictive physiologic defect with reduced exercise capacity. Over 1 year, there was no significant improvement in lung function. Similar findings were seen when participants were stratified by whether they had shortness of breath at presentation.

INTERPRETATION

In our cohort of participants with both more severe and less severe disease, there were only minor differences in lung function associated with severe illness or whether participants had shortness of breath. COVID-19 resulted in subtle changes related to physiologic restriction, but overall lung function remained in the normal range with little change over time, suggesting that other factors besides lung function contribute to shortness of breath in participants following COVID-19.

Maximal oxygen uptake, pulmonary function and walking economy are not impaired in patients diagnosed with long COVID

INTRODUCTION

SARS-CoV-2 may result in the development of new symptoms, known as long COVID, a few months after the original infection.

PURPOSE

It is elusive to what extent physical capacity in patients diagnosed with long COVID is impacted.

METHODS

We compared maximal oxygen uptake (V̇O2max), one of the single most important factors for cardiovascular health and mortality, expired lung volumes and air flow, oxygen cost of walking and 6-min-walking-test (6MWT), in 20 patients diagnosed with long COVID (11 males and 9 females; 44 ± 16 years (SD); 26.7 ± 3.8BMI, duration of acute phase 1.7 ± 1.2 weeks, tested 4 ± 3 months after long COVID diagnosis) with 20 healthy age and sex matched controls (11 males and 9 females; 44 ± 16 years; 25.9 ± 4.0BMI).

RESULTS

Long COVID patients had a V̇O2max of 41.4 ± 16.2 mL∙kg-1∙min-1(men) and 38.2 ± 7.5 (women) and this was not different from controls. Similarly, mean spirometry measures in the patient group (VC; FVC; FEV1; FEV1/FVC) were also not different (85-106%) from predicted healthy values. Finally, inclined treadmill (5%, 4 km∙h-1) walking economy was not different between the groups (long COVID: 15.2 ± 1.1 mL∙kg-1∙min-1; controls: 15.2 ± 1.2 mL∙kg-1∙min-1), while the 6MWT revealed a difference (long COVID: 606 ± 118 m; controls: 685 ± 85 m; p = 0.036).

CONCLUSION

V̇O2max, oxygen cost of walking, and spirometry measurements did not appear to be impaired in patients diagnosed with long COVID with a prior mild to moderate SARS-CoV-2 infection. The typical outcomes in these essential factors for health and longevity implies that while long COVID can present with a range of symptoms, caution should be made when attributing these symptoms directly to compromised pulmonary function or V̇O2max.

Persistent symptoms and clinical findings in adults with post-acute sequelae of COVID-19/post-COVID-19 syndrome in the second year after acute infection: A population-based, nested case-control study

BACKGROUND

Self-reported health problems following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are common and often include relatively non-specific complaints such as fatigue, exertional dyspnoea, concentration or memory disturbance and sleep problems. The long-term prognosis of such post-acute sequelae of COVID-19/post-COVID-19 syndrome (PCS) is unknown, and data finding and correlating organ dysfunction and pathology with self-reported symptoms in patients with non-recovery from PCS is scarce. We wanted to describe clinical characteristics and diagnostic findings among patients with PCS persisting for >1 year and assessed risk factors for PCS persistence versus improvement.

METHODS AND FINDINGS

This nested population-based case-control study included subjects with PCS aged 18-65 years with (n = 982) and age- and sex-matched control subjects without PCS (n = 576) according to an earlier population-based questionnaire study (6-12 months after acute infection, phase 1) consenting to provide follow-up information and to undergo comprehensive outpatient assessment, including neurocognitive, cardiopulmonary exercise, and laboratory testing in four university health centres in southwestern Germany (phase 2, another 8.5 months [median, range 3-14 months] after phase 1). The mean age of the participants was 48 years, and 65% were female. At phase 2, 67.6% of the patients with PCS at phase 1 developed persistent PCS, whereas 78.5% of the recovered participants remained free of health problems related to PCS. Improvement among patients with earlier PCS was associated with mild acute index infection, previous full-time employment, educational status, and no specialist consultation and not attending a rehabilitation programme. The development of new symptoms related to PCS among participants initially recovered was associated with an intercurrent secondary SARS-CoV-2 infection and educational status. Patients with persistent PCS were less frequently never smokers (61.2% versus 75.7%), more often obese (30.2% versus 12.4%) with higher mean values for body mass index (BMI) and body fat, and had lower educational status (university entrance qualification 38.7% versus 61.5%) than participants with continued recovery. Fatigue/exhaustion, neurocognitive disturbance, chest symptoms/breathlessness and anxiety/depression/sleep problems remained the predominant symptom clusters. Exercise intolerance with post-exertional malaise (PEM) for >14 h and symptoms compatible with myalgic encephalomyelitis/chronic fatigue syndrome were reported by 35.6% and 11.6% of participants with persistent PCS patients, respectively. In analyses adjusted for sex-age class combinations, study centre and university entrance qualification, significant differences between participants with persistent PCS versus those with continued recovery were observed for performance in three different neurocognitive tests, scores for perceived stress, subjective cognitive disturbances, dysautonomia, depression and anxiety, sleep quality, fatigue and quality of life. In persistent PCS, handgrip strength (40.2 [95% confidence interval (CI) [39.4, 41.1]] versus 42.5 [95% CI [41.5, 43.6]] kg), maximal oxygen consumption (27.9 [95% CI [27.3, 28.4]] versus 31.0 [95% CI [30.3, 31.6]] ml/min/kg body weight) and ventilatory efficiency (minute ventilation/carbon dioxide production slope, 28.8 [95% CI [28.3, 29.2]] versus 27.1 [95% CI [26.6, 27.7]]) were significantly reduced relative to the control group of participants with continued recovery after adjustment for sex-age class combinations, study centre, education, BMI, smoking status and use of beta blocking agents. There were no differences in measures of systolic and diastolic cardiac function at rest, in the level of N-terminal brain natriuretic peptide blood levels or other laboratory measurements (including complement activity, markers of Epstein-Barr virus [EBV] reactivation, inflammatory and coagulation markers, serum levels of cortisol, adrenocorticotropic hormone and dehydroepiandrosterone sulfate). Screening for viral persistence (PCR in stool samples and SARS-CoV-2 spike antigen levels in plasma) in a subgroup of the patients with persistent PCS was negative. Sensitivity analyses (pre-existing illness/comorbidity, obesity, medical care of the index acute infection) revealed similar findings. Patients with persistent PCS and PEM reported more pain symptoms and had worse results in almost all tests. A limitation was that we had no objective information on exercise capacity and cognition before acute infection. In addition, we did not include patients unable to attend the outpatient clinic for whatever reason including severe illness, immobility or social deprivation or exclusion.

CONCLUSIONS

In this study, we observed that the majority of working age patients with PCS did not recover in the second year of their illness. Patterns of reported symptoms remained essentially similar, non-specific and dominated by fatigue, exercise intolerance and cognitive complaints. Despite objective signs of cognitive deficits and reduced exercise capacity, there was no major pathology in laboratory investigations, and our findings do not support viral persistence, EBV reactivation, adrenal insufficiency or increased complement turnover as pathophysiologically relevant for persistent PCS. A history of PEM was associated with more severe symptoms and more objective signs of disease and might help stratify cases for disease severity.

Self-Reported Dyspnea Is Associated with Reduced Health-Related Quality of Life in Quaternary Hospital Workers 1 Year Post Mild COVID-19 Infection

BACKGROUND/OBJECTIVES

The COVID-19 pandemic had significant implications for healthcare workers (HWs), especially those that work in hospitals. This study evaluated health related quality of life (HRQOL) and its relationship with dyspnea approximately one year after COVID-19 infection in HWs.

METHODS

HWs with previous COVID-19 infections were interviewed, and the EuroQol five-dimensional three-level questionnaire (EQ-5D-3L) with a visual analog scale (VAS) was used to evaluate HRQOL. Self-reported clinical and sociodemographic data were also obtained. Data were stratified by the presence of self-reported dyspnea in the moment of the study interview. The association between self-reported dyspnea and HRQOL was evaluated by regression models, either unadjusted or adjusted for potential confounders (for age and sex, marital status, work category, number of comorbidities, and number of days between diagnosis and evaluation).

RESULTS

A total of 109 HWs were interviewed; the median number of days post COVID-19 diagnosis for this group was 400 (IIQ 25-75% 321-428). The majority were women (67.9%); the median age was 44 (IIQ 25-75% 38-52) years. Overall, the median EQ-5D-3L score was 0.79 (IIQ 25-75% 0.74-0.85), and the median VAS score was 80 (IIQ 25-75% 70-90). Self-reported dyspnea was indicated by 22 individuals (20.2%). Self-reported dyspnea was associated with lower EQ-5D-3L and VAS scores, both in adjusted and non-adjusted models. In addition, self-reported dyspnea was associated with more problems in carrying out usual activities in both the non-adjusted and adjusted models (p < 0.01).

CONCLUSIONS

Our results underscore the long-term implications of COVID-19, based on persistent perceptions of self-reported dyspnea and its relationship with HRQOL in HWs. Future studies, with extended follow-up and the employment of cardiopulmonary and mental health testing, may help to elucidate the nature and extent of COVID-19 sequelae.

A deeper look at long-term effects of COVID-19 on myocardial function in survivors with no prior heart diseases: a GRADE approach systematic review and meta-analysis

Objectives

The COVID-19 pandemic has challenged global health systems since December 2019, with the novel virus SARS-CoV-2 causing multi-systemic disease, including heart complications. While acute cardiac effects are well-known, long-term implications are understudied. This review hopes to fill a gap in the literature and provide valuable insights into the long-term cardiac consequences of the virus, which can inform future public health policies and clinical practices.

Methods

This systematic review was prepared using PRISMA reporting guidelines. The databases searched were PubMed, Scopus, Web of Science, and Cochrane. Risk of Bias was assessed using ROBINS-I. The GRADE approach was employed to evaluate the level of certainty in the evidence for each outcome. A meta-analysis was conducted using the Comprehensive Meta-Analysis (CMA) software. In order to identify the underlying cause of high heterogeneity, a subgroup analysis was conducted. Sensitivity analysis was checked.

Results

Sixty-six studies were included in this review. Thirty-two of them enrolled in meta-analysis and the rest in qualitative synthesis. Most outcomes showed a moderate certainty of evidence according to the GRADE framework. Post-COVID individuals with no prior heart diseases showed significant changes in left ventricular (LV) and right ventricular (RV) echocardiographic indices compared to controls. These significant findings were seen in both post-acute and long-COVID survivors regardless of the severity of initial infection.

Conclusion

This review implies that individuals recovering from post-acute and long-term effects of COVID-19 may experience changes in myocardial function as a result of the novel coronavirus. These changes, along with cardiac symptoms, have been observed in patients without prior heart diseases or comorbidities.

Systematic Review Registration

PROSPERO, identifier (CRD42024481337).

Physical exercise-related manifestations of long COVID: A systematic review and meta-analysis

Objective

This study aims to systematically assess physical exercise-related symptoms of post-acute sequelae of SARS-CoV-2 infection (PASC or long COVID) in coronavirus disease 2019 (COVID-19) survivors.

Methods

Eight databases were systematically searched on March 03, 2024. Original studies that compared physical exercise-related parameters measured by exercise testing between COVID-19 survivors who recovered from SARS-CoV-2 infection over 3 months and non-COVID-19 controls were included. A random-effects model was utilized to determine the mean differences (MDs) or standardized MDs in the meta-analysis.

Results

A total of 40 studies with 6241 COVID-19 survivors were included. The 6-min walk test, maximal oxygen consumption (VO2max), and anaerobic threshold were impaired in COVID-19 survivors 3 months post-infection compared with non-COVID-19 controls in exercise testing, while VO2 were comparable between the two groups at rest. In contrast, no differences were observed in SpO2, heart rate, blood pressure, fatigue, and dyspnea between COVID-19 survivors and non-COVID-19 controls in exercise testing.

Conclusion

The findings suggest an underestimation of the manifestations of PASC. COVID-19 survivors also harbor physical exercise-related symptoms of PASC that can be determined by the exercise testing and are distinct from those observed at rest. Exercise testing should be included while evaluating the symptoms of PASC in COVID-19 survivors.

The occurrence mechanism, assessment, and non-pharmacological treatment of dyspnea

Dyspnea is a subjective sensation often described as a feeling of respiratory effort, tightness, or air hunger. The underlying mechanisms of this symptom are multifaceted and involve factors such as respiratory centers, cardiovascular system, airways, neuromuscular components, and metabolic factors, although not fully elucidated. The classical theory of imbalance between inspiratory neural drive (IND) and the simultaneous dynamic responses of the respiratory system posits that the disruption of a normal and harmonious relationship fundamentally shapes the expression of respiratory discomfort. Assessment and comprehensive treatment of dyspnea are crucial for patient rehabilitation, including subjective self-reporting and objective clinical measurements. Non-pharmacological interventions, such as pulmonary rehabilitation, fan therapy, exercise, chest wall vibration, virtual reality technology, traditional Chinese medicine (acupuncture and acupressure), and yoga, have shown promise in alleviating dyspnea symptoms. Additionally, oxygen therapy, has demonstrated short-term benefits for patients with pre-hospital respiratory distress and hypoxemia. This review provides a comprehensive overview of dyspnea, emphasizing the importance of a multifaceted approach for its assessment and management, with a focus on non-pharmacological interventions that contribute to enhanced patient outcomes and quality of life.

Factors associated with phenotypes of dyspnea in post-COVID-19 condition: a cross-sectional study

Post-COVID-19 condition (PCC) is defined as the persistence of symptoms, like fatigue and dyspnea, at least 3 months post-COVID infection. As dyspnea is a common symptom, we attempted to further clinically phenotype those with PCC-associated dyspnea. 1642 adults (average age of 49.6y with 63% female-predominance and BMI of 31.2 kg/m2) with physician confirmed diagnosis of PCC from June 2020-April 2023 in Alberta, Canada were included. Those with dyspnea were more likely to be female (56.5%, p = 0.005) and have higher BMI (31.3 kg/m2 vs. 29.5 kg/m2; p = 0.0008), history of asthma (21.1% vs. 12.3%; p < 0.001), more persistent PCC symptoms (p = 0.0001), more functional limitations, as well as lower quality of life (p < 0.0001). Multivariable-adjusted logistic regression analysis demonstrated dyspnea was independently associated with fatigue (OR = 4.20; CI = 2.71,6.59) and inversely associated with hospitalization for COVID-19 (OR = 0.53; CI = 0.32,0.91), age (OR = 0.98 per one year of age; CI = 0.96,0.99) and 6-min-walk-distance per 10 m difference (OR = 0.98, CI = 0.96,1.0). Fatigue was a predictor of dyspnea, and was associated with milder infection, higher BMI, and reduced 6-min-walk-distance despite normal pulmonary function. Reduced TLC or DLCO was associated with more severe infection and reduced 6-min-walk-distance. Thus, we speculate there are at least two dyspnea-associated phenotypes: phenotype with pronounced fatigue (normal PFT) and phenotype with pronounced pulmonary abnormalities (abnormal PFT). Improved understanding of the dyspnea-associated phenotypes may allow for better targeted rehabilitation.

Variant-specific Symptoms After COVID-19: A Hospital-based Study in Hiroshima

BACKGROUND

Symptoms after novel coronavirus disease 2019 (COVID-19) recovery by severe acute respiratory syndrome coronavirus 2 strains are unspecified.

METHODS

This self-administered questionnaire-based study was conducted to investigate symptoms after COVID-19 recovery at one of the main hospitals for COVID-19 treatment in Hiroshima, Japan, from September 2020 to March 2022 for patients who visited follow-up consultations after COVID-19. Study subjects were divided into four groups (Wild-type, Alpha, Delta, and Omicron periods) according to COVID-19 onset date. Hierarchical cluster analysis was performed to determine symptom clusters and investigate risk factors for each symptom cluster using multivariate analysis.

RESULTS

Among 385 patients who enrolled in this study, 249 patients had any persistent symptoms at a median of 23.5 (interquartile range, 20-31) days after COVID-19 onset. Among patients with any persistent symptoms, symptom clusters including olfactory or taste disorders, respiratory symptoms, and cardiac symptoms were found. Respiratory symptoms were more frequent among patients infected in the Omicron period compared to the Wild-type period (adjusted odds ratio [AOR] 3.13; 95% confidence interval [CI], 1.31-7.48). Compared to patients who recovered from mild COVID-19, patients who needed oxygen or ventilation support suffered fewer post-COVID-19 respiratory symptoms (AOR 0.46; 95% CI, 0.22-0.97) but more post-COVID-19 cardiac symptoms among them (AOR 2.67; 95% CI, 1.26-5.65). Olfactory or taste disorders were fewer among patients infected in the Omicron period compared to the Wild-type period (AOR 0.14; 95% CI, 0.04-0.46).

CONCLUSION

This study revealed that symptoms after COVID-19 may vary depending on the infected strain.

Pathophysiological Mechanisms in Long COVID: A Mixed Method Systematic Review

INTRODUCTION

Long COVID (LC) is a global public health crisis affecting more than 70 million people. There is emerging evidence of different pathophysiological mechanisms driving the wide array of symptoms in LC. Understanding the relationships between mechanisms and symptoms helps in guiding clinical management and identifying potential treatment targets.

METHODS

This was a mixed-methods systematic review with two stages: Stage one (Review 1) included only existing systematic reviews (meta-review) and Stage two (Review 2) was a review of all primary studies. The search strategy involved Medline, Embase, Emcare, and CINAHL databases to identify studies that described symptoms and pathophysiological mechanisms with statistical analysis and/or discussion of plausible causal relationships between mechanisms and symptoms. Only studies that included a control arm for comparison were included. Studies were assessed for quality using the National Heart, Lung, and Blood Institute quality assessment tools.

RESULTS

19 systematic reviews were included in Review 1 and 46 primary studies in Review 2. Overall, the quality of reporting across the studies included in this second review was moderate to poor. The pathophysiological mechanisms with strong evidence were immune system dysregulation, cerebral hypoperfusion, and impaired gas transfer in the lungs. Other mechanisms with moderate to weak evidence were endothelial damage and hypercoagulation, mast cell activation, and auto-immunity to vascular receptors.

CONCLUSIONS

LC is a complex condition affecting multiple organs with diverse clinical presentations (or traits) underpinned by multiple pathophysiological mechanisms. A 'treatable trait' approach may help identify certain groups and target specific interventions. Future research must include understanding the response to intervention based on these mechanism-based traits.

Carotid body dysregulation contributes to Long COVID symptoms

BACKGROUND

The symptoms of long COVID, which include fatigue, breathlessness, dysregulated breathing, and exercise intolerance, have unknown mechanisms. These symptoms are also observed in heart failure and are partially driven by increased sensitivity of the carotid chemoreflex. As the carotid body has an abundance of ACE2 (the cell entry mechanism for SARS-CoV-2), we investigated whether carotid chemoreflex sensitivity was elevated in participants with long COVID.

METHODS

Non-hositalised participants with long-COVID (n = 14) and controls (n = 14) completed hypoxic ventilatory response (HVR; the measure of carotid chemoreflex sensitivity) and cardiopulmonary exercise tests. Parametric and normally distributed data were compared using Student's unpaired t-tests or ANOVA. Nonparametric equivalents were used where relevant. Peason's correlation coefficient was used to examine relationships between variables.

RESULTS

During cardiopulmonary exercise testing the VE/VCO2 slope (a measure of breathing efficiency) was higher in the long COVID group (37.8 ± 4.4) compared to controls (27.7 ± 4.8, P = 0.0003), indicating excessive hyperventilation. The HVR was increased in long COVID participants (-0.44 ± 0.23 l/min/ SpO2%, R2 = 0.77 ± 0.20) compared to controls (-0.17 ± 0.13 l/min/SpO2%, R2 = 0.54 ± 0.38, P = 0.0007). The HVR correlated with the VE/VCO2 slope (r = -0.53, P = 0.0036), suggesting that excessive hyperventilation may be related to carotid body hypersensitivity.

CONCLUSIONS

The carotid chemoreflex is sensitised in long COVID and may explain dysregulated breathing and exercise intolerance in these participants. Tempering carotid body excitability may be a viable treatment option for long COVID patients.

Symptomatic post COVID patients have impaired alveolar capillary membrane function and high VE/VCO2

BACKGROUND

Post COVID-19 syndrome is characterized by several cardiorespiratory symptoms but the origin of patients' reported symptomatology is still unclear.

METHODS

Consecutive post COVID-19 patients were included. Patients underwent full clinical evaluation, symptoms dedicated questionnaires, blood tests, echocardiography, thoracic computer tomography (CT), spirometry including alveolar capillary membrane diffusion (DM) and capillary volume (Vcap) assessment by combined carbon dioxide and nitric oxide lung diffusion (DLCO/DLNO) and cardiopulmonary exercise test. We measured surfactant derive protein B (immature form) as blood marker of alveolar cell function.

RESULTS

We evaluated 204 consecutive post COVID-19 patients (56.5 ± 14.5 years, 89 females) 171 ± 85 days after the end of acute COVID-19 infection. We measured: forced expiratory volume (FEV1) 99 ± 17%pred, FVC 99 ± 17%pred, DLCO 82 ± 19%, DM 47.6 ± 14.8 mL/min/mmHg, Vcap 59 ± 17 mL, residual parenchymal damage at CT 7.2 ± 3.2% of lung tissue, peakVO2 84 ± 18%pred, VE/VCO2 slope 112 [102-123]%pred. Major reported symptoms were: dyspnea 45% of cases, tiredness 60% and fatigability 77%. Low FEV1, Vcap and high VE/VCO2 slope were associated with persistence of dyspnea. Tiredness was associated with high VE/VCO2 slope and low PeakVO2 and FEV1 while fatigability with high VE/VCO2 slope. SPB was fivefold higher in post COVID-19 than in normal subjects, but not associated to any of the referred symptoms. SPB was negatively associated to Vcap.

CONCLUSIONS

In patients with post COVID-19, cardiorespiratory symptoms are linked to VE/VCO2 slope. In these patients the alveolar cells are dysregulated as shown by the very high SPB. The Vcap is low likely due to post COVID-19 pulmonary endothelial/vasculature damage but DLCO is only minimally impaired being DM preserved.

Long-term outcomes, residual symptoms and quality of life in COVID-19 hospitalized patients: A 12-month longitudinal study

The long-term impact of the coronavirus disease 2019 (COVID-19) pandemic is a critical public health concern. The presence of residual symptoms in COVID-19 survivors has been investigated with various results; however, there is limited data documenting outcomes longer than 6 months post-hospitalization. We aimed to investigate the 12-month lasting effects of COVID-19 in hospitalized patients. From October 2020 through March 2021, 92 patients were enrolled. At admission and 1, 3, 6, and 12 months post-hospitalization, demographic, clinical, laboratory and imaging data, and echocardiography and spirometry test results were recorded. Possible cognitive and functional impairment, as well as the quality of life (QoL), were also assessed. In our cohort (median age: 61 years), 31.5% had severe disease at admission, which correlated with worse laboratory findings and a longer hospital stay (p < 0.001). Inflammatory markers were associated with severity initially, but reverted to normal after 3 months. In total, 55%, 37%, 19%, and 15.5% of patients reported at least one persistent symptom in months 1, 3, 6, and 12, respectively, while "brain fog" persisted up to 12 months in 10% of patients. Spirometry and echocardiography tests returned to normal in most patients during the evaluation, and no one had substantial residual disease. Our study provides insight into the long-term effects of COVID-19 on patients' physical and mental health. Despite the lack of significant residual disease or major complications after a year of thorough follow-up, COVID-19 survivors experienced lasting symptoms and a negative impact on their QoL.

Assessment of a close respiratory follow-up schedule at 3 and 6 months after acute COVID-19 and its related investigations

BACKGROUND

Respiratory sequela after acute COVID-19 is common and requires medical follow-up. Considering its vast economic impact, there is still no consensus regarding the mid-term follow-up plan after recovery.

OBJECTIVE

To evaluate the necessity of a close pulmonary follow-up schedule after acute COVID-19 and its related investigations.

METHODS

A prospective cohort study including adult patients after acute COVID-19 pneumonia. Patients were invited or referred to a 3- and 6-month follow-up visits at a large pulmonary institute in a tertiary center. Before each visit, patients completed demographic and clinical questionnaires, pulmonary function tests (PFTs), and chest CT scans.

RESULTS

168 patients were included after completing both visits (medians of 80 and 177 days). Their mean age was 58 ± 15 and 52% recovered from severe or critical COVID-19. Between the two visits, there was no change in DLCOc (mean 73 ± 18 %predicted in both visits) and FVC (mean 90 ± 16 vs. 89 ± 16 %predicted). The COPD assessment tool and modified Medical Research Council scale had inverse correlations with the DLCOc, and similarly did not change between the visits. Occupational exposures were the only factor associated with a change in DLCOc during follow-up (3% decrease, p = 0.04). An improvement in chest CT findings at the second visit was not associated with a change in PFTs.

CONCLUSIONS

Most clinical variables did not change during a close follow-up schedule in the first six months after acute COVID-19. Such a follow-up plan does not appear necessary and should be personalized to limit excessive costs and resources.

Dyspnea in Post-Acute COVID-19: A Multi-Parametric Cardiopulmonary Evaluation

Post-acute COVID-19 is characterized by the persistence of dyspnea, but the pathophysiology is unclear. We evaluated the prevalence of dyspnea during follow-up and factors at admission and follow-up associated with dyspnea persistence. After five months from discharge, 225 consecutive patients hospitalized for moderate to severe COVID-19 pneumonia were assessed clinically and by laboratory tests, echocardiography, six-minute walking test (6MWT), and pulmonary function tests. Fifty-one patients reported persistent dyspnea. C-reactive protein (p = 0.025, OR 1.01 (95% CI 1.00-1.02)) at admission, longer duration of hospitalization (p = 0.005, OR 1.05 (95% CI 1.01-1.10)) and higher body mass index (p = 0.001, OR 1.15 (95% CI 1.06-1.28)) were independent predictors of dyspnea. Absolute drop in SpO₂ at 6MWT (p = 0.001, OR 1.37 (95% CI 1.13-1.69)), right ventricular (RV) global longitudinal strain (p = 0.016, OR 1.12 (95% CI 1.02-1.25)) and RV global longitudinal strain/systolic pulmonary artery pressure ratio (p = 0.034, OR 0.14 (95% CI 0.02-0.86)) were independently associated with post-acute COVID-19 dyspnea. In conclusion, dyspnea is present in many patients during follow-up after hospitalization for COVID-19 pneumonia. While higher body mass index, C-reactive protein at admission, and duration of hospitalization are predictors of persistent dyspnea, desaturation at 6MWT, and echocardiographic RV dysfunction are associated with this symptom during the follow-up period.

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.

Impact of impaired pulmonary function on clinical outcomes in survivors of severe COVID-19 without pre-existing respiratory disease

OBJECTIVE

To investigate the impact of impaired pulmonary function on patient-centered outcomes after hospital discharge due to severe COVID-19 in patients without preexisting respiratory disease.

METHODS

This is an ongoing prospective cohort study evaluating patients (> 18 years of age) 2-6 months after hospital discharge due to severe COVID-19. Respiratory symptoms, health-related quality of life, lung function, and the six-minute walk test were assessed. A restrictive ventilatory defect was defined as TLC below the lower limit of normal, as assessed by plethysmography. Chest CT scans performed during hospitalization were scored for the presence and extent of parenchymal abnormalities.

RESULTS

At a mean follow-up of 17.2 ± 5.9 weeks after the diagnosis of COVID-19, 120 patients were assessed. Of those, 23 (19.2%) reported preexisting chronic respiratory diseases and presented with worse lung function and exertional dyspnea at the follow-up visit in comparison with their counterparts. When we excluded the 23 patients with preexisting respiratory disease plus another 2 patients without lung volume measurements, a restrictive ventilatory defect was observed in 42/95 patients (44%). This subgroup of patients (52.4% of whom were male; mean age, 53.9 ± 11.3 years) showed reduced resting gas exchange efficiency (DLCO), increased daily-life dyspnea, increased exertional dyspnea and oxygen desaturation, and reduced health-related quality of life in comparison with those without reduced TLC (50.9% of whom were male; mean age, 58.4 ± 11.3 years). Intensive care need and higher chest CT scores were associated with a subsequent restrictive ventilatory defect.

CONCLUSIONS

The presence of a restrictive ventilatory defect approximately 4 months after severe COVID-19 in patients without prior respiratory comorbidities implies worse clinical outcomes.

Post-COVID dyspnea: prevalence, predictors, and outcomes in a longitudinal, prospective cohort

BACKGROUND

The pathophysiology, evolution, and associated outcomes of post-COVID dyspnea remain unknown. The aim of this study was to determine the prevalence, severity, and predictors of dyspnea 12 months following hospitalization for COVID-19, and to describe the respiratory, cardiac, and patient-reported outcomes in patients with post-COVID dyspnea.

METHODS

We enrolled a prospective cohort of all adult patients admitted to 2 academic hospitals in Vancouver, Canada with PCR-confirmed SARS-CoV-2 during the first wave of COVID between March and June 2020. Dyspnea was measured 3, 6, and 12 months after initial symptom onset using the University of California San Diego Shortness of Breath Questionnaire.

RESULTS

A total of 76 patients were included. Clinically meaningful dyspnea (baseline score > 10 points) was present in 49% of patients at 3 months and 46% at 12 months following COVID-19. Between 3 and 12 months post-COVID-19, 24% patients had a clinically meaningful worsening in their dyspnea, 49% had no meaningful change, and 28% had a clinically meaningful improvement in their dyspnea. There was worse sleep, mood, quality of life, and frailty in patients with clinically meaningful dyspnea at 12 months post-COVID infection compared to patients without dyspnea. There was no difference in PFT findings, troponin, or BNP comparing patients with and without clinically meaningful dyspnea at 12 months. Severity of dyspnea and depressive symptoms at 3 months predicted severity of dyspnea at 12 months.

CONCLUSIONS

Post-COVID dyspnea is common, persistent, and negatively impacts quality of life. Mood abnormalities may play a causative role in post-COVID dyspnea in addition to potential cardiorespiratory abnormalities. Dyspnea and depression at initial follow-up predict longer-term post-COVID dyspnea, emphasizing that standardized dyspnea and mood assessment following COVID-19 may identify patients at high risk of post-COVID dyspnea and facilitating early and effective management.

Lung pathophysiology in patients with long COVID-19: one size definitely does not fit all

Despite reduced resting lung volumes and D LCO, patients with long COVID and dyspnoea have similar physiological response to exercise to healthy subjects. D LCO impairment can marginally explain heterogeneity of complex syndromes such as long COVID. https://bit.ly/40j4aX6.

Breathlessness and exercise with virtual reality system in long-post-coronavirus disease 2019 patients

Long-post-coronavirus disease-2019 (COVID-19) patients tend to claim residual symptomatology from various systems, most importantly the respiratory and central nervous systems. Breathlessness and brain fog are the main complaints. The pulmonary function pattern is consistent with restrictive defects, which, in most cases, are self-resolved, while the cognitive profile may be impaired. Rehabilitation is an ongoing field for holistic management of long-post-COVID-19 patients. Virtual reality (VR) applications may represent an innovative implementation of rehabilitation. We aimed to investigate the effect of exercise with and without the VR system and to assess further breathlessness and functional fitness indicators in long-post-COVID-19 patients with mild cognitive impairment after self-selected exercise duration using the VR system. Twenty long-post-COVID-19 patients were enrolled in our study (age: 53.9 ± 9.1 years, male: 80%, body mass index: 28.1 ± 3.1 kg/m²). Participants' anthropometric data were recorded, and they underwent pulmonary functional test evaluation as well as sleep quality and cognitive assessment. The participants randomly exercised with and without a VR system (VR vs. no-VR) and, later, self-selected the exercise duration using the VR system. The results showed that exercise with VR resulted in a lower dyspnea score than exercise without VR. In conclusion, VR applications seem to be an attractive and safe tool for implementing rehabilitation. They can enhance performance during exercise and benefit patients with both respiratory and cognitive symptoms.

Dyspnea: a map of Cochrane evidence relevant to rehabilitation for people with post COVID-19 condition

INTRODUCTION

Rehabilitation focuses on impairments, activity limitations and participation restrictions being informed by the underlying health condition. In the current absence of direct "evidence on" rehabilitation interventions for people with post COVID-19 condition (PCC), we can search and synthesize the indirect "evidence relevant to" coming from interventions effective on the symptoms of PCC in other health conditions. The World Health Organization (WHO) required this information to inform expert teams and provide specific recommendations in their Guidelines. With this overview of reviews with mapping we aimed to synthesize in a map the Cochrane evidence relevant to rehabilitation for dyspnea due to PCC.

EVIDENCE ACQUISITION

We searched the last five years' Cochrane Systematic Review (CSRs) using the terms "dyspnea" and its synonyms in the Cochrane Library. We extracted and summarized all the available evidence using a map. We grouped the included CSRs for health conditions and interventions, indicating the effect and the quality of evidence.

EVIDENCE SYNTHESIS

We found 371 CSRs published between 2016 and 2021 and included 15 in this overview. We found eight studies on chronic obstructive pulmonary disease, two on cancer, and one for bronchiectasis, chronic respiratory disease, cystic fibrosis, idiopathic pulmonary fibrosis and interstitial lung disease. Effective interventions included pulmonary rehabilitation, also in combination with exercise training, non-invasive ventilation, upper limb training and multicomponent integrated interventions, with very low- to moderate-quality evidence.

CONCLUSIONS

These results are the first step of indirect evidence to generate helpful hypotheses for clinical practice and future research on dyspnea in adults with PCC. They served as the basis for one recommendation on treatments for dyspnea as a PCC symptom published in the current WHO Guidelines for clinical practice.