Use of latent class analysis and patient reported outcome measures to identify distinct long COVID phenotypes: A longitudinal cohort study.

OBJECTIVES: We sought to 1) identify long COVID phenotypes based on patient reported outcome measures (PROMs) and 2) determine whether the phenotypes were associated with quality of life (QoL) and/or lung function. METHODS: This was a longitudinal cohort study of hospitalized and non-hospitalized patients from March 2020 to January 2022 that was conducted across 4 Post-COVID Recovery Clinics in British Columbia, Canada. Latent class analysis was used to identify long COVID phenotypes using baseline PROMs (fatigue, dyspnea, cough, anxiety, depression, and post-traumatic stress disorder). We then explored the association between the phenotypes and QoL (using the EuroQoL 5 dimensions visual analogue scale [EQ5D VAS]) and lung function (using the diffusing capacity of the lung for carbon monoxide [DLCO]). RESULTS: There were 1,344 patients enrolled in the study (mean age 51 ±15 years; 780 [58%] were females; 769 (57%) were of a non-White race). Three distinct long COVID phenotypes were identified: Class 1) fatigue and dyspnea, Class 2) anxiety and depression, and Class 3) fatigue, dyspnea, anxiety, and depression. Class 3 had a significantly lower EQ5D VAS at 3 (50±19) and 6 months (54 ± 22) compared to Classes 1 and 2 (p<0.001). The EQ5D VAS significantly improved between 3 and 6 months for Class 1 (median difference of 6.0 [95% CI, 4.0 to 8.0]) and Class 3 (median difference of 5.0 [95% CI, 0 to 8.5]). There were no differences in DLCO between the classes. CONCLUSIONS: There were 3 distinct long COVID phenotypes with different outcomes in QoL between 3 and 6 months after symptom onset. These phenotypes suggest that long COVID is a heterogeneous condition with distinct subpopulations who may have different outcomes and warrant tailored therapeutic approaches.

Evaluating fatigue in patients recovering from COVID-19: validation of the fatigue severity scale and single item screening questions.

BACKGROUND: Fatigue is a common symptom in hospitalized and non-hospitalized patients recovering from COVID-19, but no fatigue measurement scales or questions have been validated in these populations. The objective of this study was to perform validity assessments of the fatigue severity scale (FSS) and two single-item screening questions (SISQs) for fatigue in patients recovering from COVID-19. METHODS: We examined patients ≥ 28 days after their first SARS-CoV-2 infection who were hospitalized for their acute illness, as well as non-hospitalized patients referred for persistent symptoms. Patients completed questionnaires through 1 of 4 Post COVID-19 Recovery Clinics in British Columbia, Canada. Construct validity was assessed by comparing FSS scores to quality of life and depression measures. Two SISQs were evaluated based on the ability to classify fatigue (FSS score ≥ 4). RESULTS: Questionnaires were returned in 548 hospitalized and 546 non-hospitalized patients, with scores computable in 96.4% and 98.2% of patients respectively. Cronbach's alpha was 0.96 in both groups. The mean ± SD FSS score was 4.4 ± 1.8 in the hospitalized and 5.2 ± 1.6 in the non-hospitalized group, with 62.5% hospitalized and 78.9% non-hospitalized patients classified as fatigued. Ceiling effects were 7.6% in the hospitalized and 16.1% in non-hospitalized patients. FSS scores negatively correlated with EQ-5D scores in both groups (Spearman's rho - 0.6 in both hospitalized and non-hospitalized; p < 0.001) and were higher among patients with a positive PHQ-2 depression screen (5.4 vs. 4.0 in hospitalized and 5.9 vs. 4.9 in non-hospitalized; p < 0.001). An SISQ asking whether there was "fatigue present" had a sensitivity of 70.6% in hospitalized and 83.2% in non-hospitalized patients; the "always feeling tired" SISQ, had a sensitivity of 70.5% and 89.6% respectively. CONCLUSIONS: Fatigue was common and severe in patients referred for post COVID-19 assessment. Overall, the FSS is suitable for measuring fatigue in these patients, as there was excellent data quality, strong internal consistency, and construct validity. However, ceiling effects may be a limitation in the non-hospitalized group. SISQs had good sensitivity for identifying clinically relevant fatigue in non-hospitalized patients but only moderate sensitivity in the hospitalized group, indicating that there were more false negatives.

Redefining critical illness.

Research and practice in critical care medicine have long been defined by syndromes, which, despite being clinically recognizable entities, are, in fact, loose amalgams of heterogeneous states that may respond differently to therapy. Mounting translational evidence-supported by research on respiratory failure due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-suggests that the current syndrome-based framework of critical illness should be reconsidered. Here we discuss recent findings from basic science and clinical research in critical care and explore how these might inform a new conceptual model of critical illness. De-emphasizing syndromes, we focus on the underlying biological changes that underpin critical illness states and that may be amenable to treatment. We hypothesize that such an approach will accelerate critical care research, leading to a richer understanding of the pathobiology of critical illness and of the key determinants of patient outcomes. This, in turn, will support the design of more effective clinical trials and inform a more precise and more effective practice at the bedside.

Renin-Angiotensin System Pathway Therapeutics Associated With Improved Outcomes in Males Hospitalized With COVID-19.

OBJECTIVES: To determine whether angiotensin receptor blockers (ARBs) or angiotensin-converting enzyme (ACE) inhibitors are associated with improved outcomes in hospitalized patients with COVID-19 according to sex and to report sex-related differences in renin-angiotensin system (RAS) components. DESIGN: Prospective observational cohort study comparing the effects of ARB or ACE inhibitors versus no ARBs or ACE inhibitors in males versus females. Severe acute respiratory syndrome coronavirus 2 downregulates ACE-2, potentially increasing angiotensin II (a pro-inflammatory vasoconstrictor). Sex-based differences in RAS dysregulation may explain sex-based differences in responses to ARBs because the ACE2 gene is on the X chromosome. We recorded baseline characteristics, comorbidities, prehospital ARBs or ACE inhibitor treatment, use of organ support and mortality, and measured RAS components at admission and days 2, 4, 7, and 14 in a subgroup ( n = 46), recorded d -dimer ( n = 967), comparing males with females. SETTING: ARBs CORONA I is a multicenter Canadian observational cohort of patients hospitalized with acute COVID-19. This analysis includes patients admitted to 10 large urban hospitals across the four most populated provinces. PATIENTS: One-thousand six-hundred eighty-six patients with polymerase chain reaction-confirmed COVID-19 (February 2020 to March 2021) for acute COVID-19 illness were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Males on ARBs before admission had decreased use of ventilation (adjusted odds ratio [aOR] = 0.52; p = 0.007) and vasopressors (aOR = 0.55; p = 0.011) compared with males not on ARBs or ACE inhibitors. No significant effects were observed in females for these outcomes. The test for interaction was significant for use of ventilation ( p = 0.006) and vasopressors ( p = 0.044) indicating significantly different responses to ARBs according to sex. Males had significantly higher plasma ACE-1 at baseline and angiotensin II at day 7 and 14 than females. CONCLUSIONS: ARBs use was associated with less ventilation and vasopressors in males but not females. Sex-based differences in RAS dysregulation may contribute to sex-based differences in outcomes and responses to ARBs in COVID-19.

Organ dysfunction and death in patients admitted to hospital with COVID-19 in pandemic waves 1 to 3 in British Columbia, Ontario and Quebec, Canada: a cohort study.

BACKGROUND: There have been multiple waves in the COVID-19 pandemic in many countries. We sought to compare mortality and respiratory, cardiovascular and renal dysfunction between waves in 3 Canadian provinces. METHODS: We conducted a substudy of the ARBs CORONA I study, a multicentre Canadian pragmatic observational cohort study that examined the association of pre-existing use of angiotensin receptor blockers with outcomes in adults admitted to hospital with acute COVID-19 up to April 2021 from 9 community and teaching hospitals in 3 Canadian provinces (British Columbia, Ontario and Quebec). We excluded emergency department admissions without hospital admission, readmissions and admissions for another reason. We used logistic and 0-1-inflated ß regression models to compare 28-day and in-hospital mortality, and the use of invasive mechanical ventilation, vasopressors and renal replacement therapy (RRT) between the first 3 waves of the COVID-19 pandemic in these provinces. RESULTS: A total of 520, 572 and 245 patients in waves 1, 2 and 3, respectively, were included. Patients in wave 3 were on average younger and had fewer comorbidities than those in waves 1 and 2. The unadjusted 28-day mortality rate was significantly lower in wave 3 (7.8%) than in wave 1 (18.3%) (odds ratio [OR] 0.43, 95% confidence interval [CI] 0.24-0.78) and wave 2 (16.3%) (OR 0.46, 95% CI 0.27-0.79). After adjustment for differences in baseline characteristics, the difference in 28-day mortality remained significant (adjusted OR wave 3 v. wave 1: 0.46, 95% CI 0.26-0.81; wave 3 v. wave 2: 0.52, 95% CI 0.29-0.91). In-hospital mortality findings were similar. Use of invasive mechanical ventilation or vasopressors was less common in waves 2 and 3 than in wave 1, and use of RRT was less common in wave 3 than in wave 1. INTERPRETATION: Severity of illness decreased (lower mortality and less use of organ support) across waves among patients admitted to hospital with acute COVID-19, possibly owing to changes in patient demographic characteristics and management, such as increased use of dexamethasone. Continued application of proven therapies may further improve outcomes. STUDY REGISTRATION: ClinicalTrials.gov, no. NCT04510623.

Longitudinal Plasma Proteomics Analysis Reveals Novel Candidate Biomarkers in Acute COVID-19.

The host response to COVID-19 pathophysiology over the first few days of infection remains largely unclear, especially the mechanisms in the blood compartment. We report on a longitudinal proteomic analysis of acute-phase COVID-19 patients, for which we used blood plasma, multiple reaction monitoring with internal standards, and data-independent acquisition. We measured samples on admission for 49 patients, of which 21 had additional samples on days 2, 4, 7, and 14 after admission. We also measured 30 externally obtained samples from healthy individuals for comparison at baseline. The 31 proteins differentiated in abundance between acute COVID-19 patients and healthy controls belonged to acute inflammatory response, complement activation, regulation of inflammatory response, and regulation of protein activation cascade. The longitudinal analysis showed distinct profiles revealing increased levels of multiple lipid-associated functions, a rapid decrease followed by recovery for complement activation, humoral immune response, and acute inflammatory response-related proteins, and level fluctuation in the regulation of smooth muscle cell proliferation, secretory mechanisms, and platelet degranulation. Three proteins were differentiated between survivors and nonsurvivors. Finally, increased levels of fructose-bisphosphate aldolase B were determined in patients with exposure to angiotensin receptor blockers versus decreased levels in those exposed to angiotensin-converting enzyme inhibitors. Data are available via ProteomeXchange PXD029437.

Acute Cardiac Injury in Coronavirus Disease 2019 and Other Viral Infections-A Systematic Review and Meta-Analysis.

OBJECTIVES: Severe acute respiratory syndrome-related coronavirus-2 binds and inhibits angiotensin-converting enzyme-2. The frequency of acute cardiac injury in patients with coronavirus disease 2019 is unknown. The objective was to compare the rates of cardiac injury by angiotensin-converting enzyme-2-binding viruses from viruses that do not bind to angiotensin-converting enzyme-2. DATA SOURCES: We performed a systematic review of coronavirus disease 2019 literature on PubMed and EMBASE. STUDY SELECTION: We included studies with ten or more hospitalized adults with confirmed coronavirus disease 2019 or other viral pathogens that described the occurrence of acute cardiac injury. This was defined by the original publication authors or by: 1) myocardial ischemia, 2) new cardiac arrhythmia on echocardiogram, or 3) new or worsening heart failure on echocardiogram. DATA EXTRACTION: We compared the rates of cardiac injury among patients with respiratory infections with viruses that down-regulate angiotensin-converting enzyme-2, including H1N1, H5N1, H7N9, and severe acute respiratory syndrome-related coronavirus-1, to those with respiratory infections from other influenza viruses that do not bind angiotensin-converting enzyme-2, including Influenza H3N2 and influenza B. DATA SYNTHESIS: Of 57 studies including 34,072 patients, acute cardiac injury occurred in 50% (95% CI, 44-57%) of critically ill patients with coronavirus disease 2019. The overall risk of acute cardiac injury was 21% (95% CI, 18-26%) among hospitalized patients with coronavirus disease 2019. In comparison, 37% (95% CI, 26-49%) of critically ill patients with other respiratory viruses that bind angiotensin-converting enzyme-2 (p = 0.061) and 12% (95% CI, 7-22%) of critically ill patients with other respiratory viruses that do not bind angiotensin-converting enzyme-2 (p < 0.001) experienced a cardiac injury. CONCLUSIONS: Acute cardiac injury may be associated with whether the virus binds angiotensin-converting enzyme-2. Acute cardiac injury occurs in half of critically ill coronavirus disease 2019 patients, but only 12% of patients infected by viruses that do not bind to angiotensin-converting enzyme-2.

Angiotensin Receptor Blockers and Angiotensin-Converting Enzyme Inhibitors in COVID-19: Meta-analysis/Meta-regression Adjusted for Confounding Factors.

BACKGROUND: Angiotensin receptor blockers (ARBs) and/or angiotensin-converting enzyme (ACE) inhibitors could alter mortality from coronavirus disease 2019 (COVID-19), but existing meta-analyses that combined crude and adjusted results may be confounded by the fact that comorbidities are more common in ARB/ACE inhibitor users. METHODS: We searched PubMed/MEDLINE/Embase for cohort studies and meta-analyses reporting mortality by preexisting ARB/ACE inhibitor treatment in hospitalized COVID-19 patients. Random effects meta-regression was used to compute pooled odds ratios for mortality adjusted for imbalance in age, sex, and prevalence of cardiovascular disease, hypertension, diabetes mellitus, and chronic kidney disease between users and nonusers of ARBs/ACE inhibitors at the study level during data synthesis. RESULTS: In 30 included studies of 17,281 patients, 22%, 68%, 25%, and 11% had cardiovascular disease, hypertension, diabetes mellitus, and chronic kidney disease. ARB/ACE inhibitor use was associated with significantly lower mortality after controlling for potential confounding factors (odds ratio 0.77 [95% confidence interval: 0.62, 0.96]). In contrast, meta-analysis of ARB/ACE inhibitor use was not significantly associated with mortality when all studies were combined with no adjustment made for confounders (0.87 [95% confidence interval: 0.71, 1.08]). CONCLUSIONS: ARB/ACE inhibitor use was associated with decreased mortality in cohorts of COVID-19 patients after adjusting for age, sex, cardiovascular disease, hypertension, diabetes, and chronic kidney disease. Unadjusted meta-analyses may not be appropriate for determining whether ARBs/ACE inhibitors are associated with mortality from COVID-19 because of indication bias.

INTRODUCTION: Les antagonistes des récepteurs de l'angiotensine (ARA) et/ou les inhibiteurs de l'enzyme de conversion de l'angiotensine (IECA) feraient varier la mortalité liée à la COVID-19, mais il est possible que les méta-analyses actuelles qui combinaient les résultats bruts et ajustés soient invalidées du fait que les comorbidités sont plus fréquentes chez les utilisateurs d'ARA/IECA. MÉTHODES: Nous avons effectué des recherches dans les bases de données PubMed/MEDLINE/Embase pour trouver des études de cohorte et des méta-analyses qui portent sur la mortalité associée à un traitement préexistant par ARA/IECA chez les patients hospitalisés atteints de la COVID-19. Nous avons utilisé la métarégression à effets aléatoires pour calculer les rapports de cotes regroupés de mortalité ajustés en fonction du déséquilibre de l'âge, du sexe, et de la prévalence des maladies cardiovasculaires, de l'hypertension, du diabète sucré et de l'insuffisance rénale chronique entre les utilisateurs et les non-utilisateurs d'ARA/IECA dans le cadre de l'étude durant la synthèse des données. RÉSULTATS: Dans les 30 études portant sur 17 281 patients, 22 %, 68 %, 25 % et 11 % avaient respectivement une maladie cardiovasculaire, de l'hypertension, le diabète sucré et de l'insuffisance rénale chronique. L'utilisation des ARA/IECA a été associée à une mortalité significativement plus faible après avoir tenu compte des facteurs confusionnels potentiels (rapport de cotes 0,77 [intervalle de confiance à 95 % : 0,62, 0,96]). En revanche, la méta-analyse sur l'utilisation des ARA/IECA n'a pas été associée de façon significative à la mortalité lorsque toutes les études ont été combinées sans ajustement sur les facteurs confusionnels (0,87 [intervalle de confiance à 95 % : 0,71, 1,08]). CONCLUSIONS: L'utilisation des ARA/IECA a été associée à la diminution de la mortalité au sein des cohortes de patients atteints de la COVID-19 après l'ajustement en fonction de l'âge, du sexe, des maladies cardiovasculaires, de l'hypertension, du diabète et de l'insuffisance rénale chronique. Les méta-analyses non ajustées peuvent ne pas permettre de déterminer si les ARA/IECA sont associés à la mortalité liée à la COVID-19 en raison du biais d'indication.

Study protocol for a multicentre, prospective cohort study of the association of angiotensin II type 1 receptor blockers on outcomes of coronavirus infection.

INTRODUCTION: The COVID-19 epidemic grows and there are clinical trials of antivirals. There is an opportunity to complement these trials with investigation of angiotensin II type 1 receptor blockers (ARBs) because an ARB (losartan) was effective in murine influenza pneumonia. METHODS AND ANALYSIS: Our innovative design includes: ARBs; alignment with the WHO Ordinal Scale (primary endpoint) to align with other COVID-19 trials; joint longitudinal analysis; and predictive biomarkers (angiotensins I, 1-7, II and ACE1 and ACE2). Our hypothesis is: ARBs decrease the need for hospitalisation, severity (need for ventilation, vasopressors, extracorporeal membrane oxygenation or renal replacement therapy) or mortality of hospitalised COVID-19 infected adults. Our two-pronged multicentre pragmatic observational cohort study examines safety and effectiveness of ARBs in (1) hospitalised adult patients with COVID-19 and (2) out-patients already on or not on ARBs. The primary outcome will be evaluated by ordinal logistic regression and main secondary outcomes by both joint longitudinal modelling analyses. We will compare rates of hospitalisation of ARB-exposed versus not ARB-exposed patients. We will also determine whether continuing ARBs or not decreases the primary outcome. Based on published COVID-19 cohorts, assuming 15% of patients are ARB-exposed, a total sample size of 497 patients can detect a proportional OR of 0.5 (alpha=0.05, 80% power) comparing WHO scale of ARB-exposed versus non-ARB-exposed patients. ETHICS AND DISSEMINATION: This study has core institution approval (UBC Providence Healthcare Research Ethics Board) and site institution approvals (Health Research Ethics Board, University of Alberta; Comite d'etique de la recerche, CHU Sainte Justine (for McGill University and University of Sherbrook); Conjoint Health Research Ethics Board, University of Calgary; Queen's University Health Sciences & Affiliated Hospitals Research Ethics Board; Research Ethics Board, Sunnybrook Health Sciences Centre; Veritas Independent Research Board (for Humber River Hospital); Mount Sinai Hospital Research Ethics Board; Unity Health Toronto Research Ethics Board, St. Michael's Hospital). Results will be disseminated by peer-review publication and social media releases. TRIAL REGISTRATION NUMBER: NCT04510623.