Systematic review and meta-analysis of randomized controlled trials of mesenchymal stromal cells to treat coronavirus disease 2019: is it too late?

BACKGROUND AIMS: Evidence regarding the extent that mesenchymal stromal cells (MSCs) may improve clinical outcomes in patients with coronavirus disease 2019 (COVID-19) has been limited by marked inter-study heterogeneity, inconsistent product characterization and appreciable risk of bias (RoB). Given the evolution of treatment options and trajectory of the pandemic, an updated analysis of high-quality evidence from randomized controlled trials is needed for a timely and conclusive understanding of the effectiveness of MSCs. METHODS: A systematic literature search through March 30, 2022, identified all English language, full-text randomized controlled trials examining the use of MSCs in the treatment of COVID-19. RESULTS: Eight studies were identified (316 patients, 165 administered MSCs and 151 controls). Controls evolved significantly over time with a broad range of comparison treatments. All studies reported mortality at study endpoint. Random effects meta-analysis revealed that MSCs decreased relative risk of death (risk ratio, 0.63, 95% confidence interval, 0.42-0.94, P = 0.02, I2 = 14%) with no significant difference in absolute risk of death. MSCs decreased length of hospital stay and C-reactive protein levels and increased odds of clinical improvement at study endpoint compared with controls. Rates of adverse events and severe adverse events were similar between MSC and control groups. Only two (25%) studies reported all four International Society for Cell & Gene Therapy criteria for MSC characterization. Included studies had low (n = 7) or some (n = 1) concerns regarding RoB. CONCLUSIONS: MSCs may reduce risk of death in patients with severe or critical COVID-19 and improve secondary clinical outcomes. Variable outcome reporting, inconsistent product characterization and variable control group treatments remain barriers to higher-quality evidence and may constrain clinical usage. A master protocol is proposed and appears necessary for accelerated translation of higher-quality evidence for future applications of MSC therapy.

Updated Living Systematic Review and Meta-analysis of Controlled Trials of Mesenchymal Stromal Cells to Treat COVID-19: A Framework for Accelerated Synthesis of Trial Evidence for Rapid Approval-FASTER Approval.

BACKGROUND: Mesenchymal stromal cells (MSCs) may reduce mortality in patients with COVID-19; however, early evidence is based on few studies with marked interstudy heterogeneity. The second iteration of our living systematic review and meta-analysis evaluates a framework needed for synthesizing evidence from high-quality studies to accelerate consideration for approval. METHODS: A systematic search of the literature was conducted on November 15, 2021, to identify all English-language, full-text, and controlled clinical studies examining MSCs to treat COVID-19 (PROSPERO: CRD42021225431). FINDINGS: Eleven studies were identified (403 patients with severe and/or critical COVID-19, including 207 given MSCs and 196 controls). All 11 studies reported mortality and were pooled through random-effects meta-analysis. MSCs decreased relative risk of death at study endpoint (RR: 0.50 [95% CI, 0.34-0.75]) and RR of death at 28 days after treatment (0.19 [95% CI], 0.05-0.78) compared to controls. MSCs also decreased length of hospital stay (mean difference (MD: -3.97 days [95% CI, -6.09 to -1.85], n = 5 studies) and increased oxygenation levels at study endpoint compared to controls (MD: 105.62 mmHg O2 [95% CI, 73.9-137.3,], n = 3 studies). Only 2 of 11 studies reported on all International Society for Cellular Therapy (ISCT) criteria for MSC characterization. Included randomized controlled trials were found to have some concerns (n = 2) to low (n = 4) risk of bias (RoB), while all non-randomized studies were found to have moderate (n = 5) RoB. INTERPRETATION: Our updated living systematic review concludes that MSCs can likely reduce mortality in patients with severe or critical COVID-19. A master protocol based on our Faster Approval framework appears necessary to facilitate the more accelerated accumulation of high-quality evidence that would reduce RoB, improve consistency in product characterization, and standardize outcome reporting.

Airway recommendations for perioperative patients during the COVID-19 pandemic: a scoping review.

PURPOSE: Numerous guideline recommendations for airway and perioperative management during the COVID-19 pandemic have been published. We identified, synthesized, and compared guidelines intended for anesthesiologists. SOURCE: Member society websites of the World Federation of Societies of Anesthesiologists and the European Society of Anesthesiologists were searched. Recommendations that focused on perioperative airway management of patients with proven or potential COVID-19 were included. Accelerated screening was used; data were extracted by one reviewer and verified by a second. Data were organized into themes based on perioperative phase of care. PRINCIPAL FINDINGS: Thirty unique sets of recommendations were identified. None reported methods for systematically searching or selecting evidence to be included. Four were updated following initial publication. For induction and airway management, most recommended minimizing personnel and having the most experienced anesthesiologist perform tracheal intubation. Significant congruence was observed among recommendations that discussed personal protective equipment. Of those that discussed tracheal intubation methods, most (96%) recommended videolaryngoscopy, while discordance existed regarding use of flexible bronchoscopy. Intraoperatively, 23% suggested specific anesthesia techniques and most (63%) recommended a specific operating room for patients with COVID-19. Postoperatively, a minority discussed extubation procedures (33%), or care in the recovery room (40%). Non-technical considerations were discussed in 27% and psychological support for healthcare providers in 10%. CONCLUSION: Recommendations for perioperative airway management of patients with COVID-19 overlap to a large extent but also show significant differences. Given the paucity of data early in the pandemic, it is not surprising that identified publications largely reflected expert opinion rather than empirical evidence. We suggest future efforts should promote coordinated responses and provide suggestions for studying and establishing best practices in perioperative patients. STUDY REGISTRATION: Open Science Framework ( https://osf.io/a2k4u/ ); date created, 26 March 2020.

RéSUMé: OBJECTIF: De nombreuses recommandations ont été publiées pour la prise en charge des voies aériennes et périopératoires pendant la pandémie de COVID-19. Nous avons identifié, synthétisé et comparé les lignes directrices destinées aux anesthésiologistes. SOURCES: Les sites internet des sociétés membres de la Fédération mondiale des sociétés d'anesthésiologistes et de la Société européenne d'anesthésiologie ont été consultés. Les recommandations axées sur la prise en charge périopératoire des voies aériennes des patients atteints de COVID-19 prouvée ou potentielle ont été incluses. Une sélection accélérée a été utilisée; les données ont été extraites par un examinateur et vérifiées par un second. Les données ont été thématiquement organisées en fonction de la phase périopératoire des soins. CONSTATATIONS PRINCIPALES: Trente ensembles uniques de recommandations ont été identifiés. Aucun de ces ensemble n'a fait état de méthodes de recherche ou de sélection systématiques des données probantes à inclure. Quatre ont été mis à jour après leur publication initiale. Pour l'induction et la prise en charge des voies aériennes, la plupart ont recommandé de minimiser le personnel et de demander à l'anesthésiologiste le plus expérimenté de réaliser l'intubation trachéale. Une congruence significative a été observée parmi les recommandations qui portaient sur les équipements de protection individuelle. Parmi les lignes directrices évoquant les méthodes d'intubation trachéale, la plupart (96 %) ont recommandé la vidéolaryngoscopie, alors qu'il existait une discordance concernant l'utilisation de bronchoscopes flexibles. En peropératoire, 23 % ont suggéré des techniques d'anesthésie spécifiques et la plupart (63 %) ont recommandé une salle d'opération spécifique pour les patients atteints de COVID-19. En postopératoire, une minorité a abordé le sujet des procédures d'extubation (33 %) ou des soins en salle de réveil (40 %). Les considérations non techniques ont été traitées dans 27 % des cas et le soutien psychologique aux fournisseurs de soins de santé dans 10 %. CONCLUSION: Les recommandations pour la prise en charge périopératoire des voies aériennes des patients atteints de COVID-19 se chevauchent dans une large mesure, mais montrent également des différences significatives. Compte tenu de la rareté des données au début de la pandémie, il n'est pas surprenant que les publications identifiées reflètent en grande partie l'opinion d'experts plutôt que de se fonder sur des données probantes empiriques. Nous suggérons que les efforts futurs soient déployés de manière à promouvoir des réponses coordonnées et proposer des suggestions pour étudier et établir les meilleures pratiques chez les patients en période périopératoire. ENREGISTREMENT DE L'éTUDE: Open Science Framework ( https://osf.io/a2k4u/ ); date de création, 26 mars 2020.

Mesenchymal stem/stromal cell-based therapies for COVID-19: First iteration of a living systematic review and meta-analysis: MSCs and COVID-19.

BACKGROUND: Mesenchymal stem/stromal cells (MSCs) and their secreted products are a promising therapy for COVID-19 given their immunomodulatory and tissue repair capabilities. Many small studies were launched at the onset of the pandemic, and repeated meta-analysis is critical to obtain timely and sufficient statistical power to determine efficacy. METHODS AND FINDINGS: All English-language published studies identified in our systematic search (up to February 3, 2021) examining the use of MSC-derived products to treat patients with COVID-19 were identified. Risk of bias (RoB) was assessed for all studies. Nine studies were identified (189 patients), four of which were controlled (93 patients). Three of the controlled studies reported on mortality (primary analysis) and were pooled through random-effects meta-analysis. MSCs decreased the risk of death at study endpoint compared with controls (risk ratio, 0.18; 95% confidence interval [CI], 0.04 to 0.74; P = .02; I2 = 0%), although follow-up differed. Among secondary outcomes, interleukin-6 levels were most commonly reported and were decreased compared with controls (standardized mean difference, -0.69; 95% CI, -1.15 to -0.22; P = .004; I2 = 0%) (n = 3 studies). Other outcomes were not reported consistently, and pooled estimates of effect were not performed. Substantial heterogeneity was observed between studies in terms of study design. Adherence to published ISCT criteria for MSC characterization was low. In two of nine studies, RoB analysis revealed a low to moderate risk of bias in controlled studies, and uncontrolled case series were of good (3 studies) or fair (2 studies) quality. CONCLUSION: Use of MSCs to treat COVID-19 appears promising; however, few studies were identified, and potential risk of bias was detected in all studies. More controlled studies that report uniform clinical outcomes and use MSC products that meet standard ISCT criteria should be performed. Future iterations of our systematic search should refine estimates of efficacy and clarify potential adverse effects.

Mesenchymal stromal cell extracellular vesicles as therapy for acute and chronic respiratory diseases: A meta-analysis.

Preclinical studies suggest mesenchymal stromal cell extracellular vesicles (MSC-EVs) reduce inflammation and improve organ function in lung diseases; however, an objective analysis of all available data is needed prior to translation. Using rigorous meta-research methods, we determined the effectiveness of MSC-EVs for preclinical respiratory diseases and identified experimental conditions that may further refine this therapy. A systematic search of MEDLINE/Embase identified 1167 records. After screening, 52 articles were included for data extraction and evaluated for risk of bias and quality of reporting in study design. A random effects meta-analysis was conducted for acute lung injury (ALI; N = 23), bronchopulmonary dysplasia (BPD; N = 8) and pulmonary arterial hypertension (PAH; N = 7). Subgroup analyses identified EV methods/characteristics that may be associated with improved efficacy. Data is presented as standardized mean differences (SMD) or risk ratios (RR) with 95% confidence intervals (CI). For ALI, MSC-EVs markedly reduced lung injury (SMD -4.33, CI -5.73 to -2.92), vascular permeability (SMD -2.43, CI -3.05 to -1.82), and mortality (RR 0.39, CI 0.22 to 0.68). Small EVs were more consistently effective than large EVs whereas no differences were observed between tissue sources, immunocompatibility or isolation techniques. For BPD, alveolarization was improved by MSC-EVs (SMD -1.45, CI -2.08 to -0.82) with small EVs more consistently beneficial then small/large EVs. In PAH, right ventricular systolic pressure (SMD -4.16, CI -5.68 to -2.64) and hypertrophy (SMD -2.80, CI -3.68 to -1.91) were significantly attenuated by EVs. In BPD and PAH, EVs isolated by ultracentrifugation demonstrated therapeutic benefit whereas tangential flow filtration (N = 2) displayed minimal efficacy. Lastly, risk of bias and quality of reporting for experimental design were consistently unclear across all studies. Our findings demonstrate clear potential of MSC-EVs to be developed as therapy for acute and chronic lung diseases. However, greater transparency in research design and direct comparisons of isolation technique and EV subtypes are needed to generate robust evidence to guide clinical translation. Protocol Registration: PROSPERO CRD42020145334.

Post-discharge after surgery Virtual Care with Remote Automated Monitoring-1 (PVC-RAM-1) technology versus standard care: randomised controlled trial.

OBJECTIVE: To determine if virtual care with remote automated monitoring (RAM) technology versus standard care increases days alive at home among adults discharged after non-elective surgery during the covid-19 pandemic. DESIGN: Multicentre randomised controlled trial. SETTING: 8 acute care hospitals in Canada. PARTICIPANTS: 905 adults (≥40 years) who resided in areas with mobile phone coverage and were to be discharged from hospital after non-elective surgery were randomised either to virtual care and RAM (n=451) or to standard care (n=454). 903 participants (99.8%) completed the 31 day follow-up. INTERVENTION: Participants in the experimental group received a tablet computer and RAM technology that measured blood pressure, heart rate, respiratory rate, oxygen saturation, temperature, and body weight. For 30 days the participants took daily biophysical measurements and photographs of their wound and interacted with nurses virtually. Participants in the standard care group received post-hospital discharge management according to the centre's usual care. Patients, healthcare providers, and data collectors were aware of patients' group allocations. Outcome adjudicators were blinded to group allocation. MAIN OUTCOME MEASURES: The primary outcome was days alive at home during 31 days of follow-up. The 12 secondary outcomes included acute hospital care, detection and correction of drug errors, and pain at 7, 15, and 30 days after randomisation. RESULTS: All 905 participants (mean age 63.1 years) were analysed in the groups to which they were randomised. Days alive at home during 31 days of follow-up were 29.7 in the virtual care group and 29.5 in the standard care group: relative risk 1.01 (95% confidence interval 0.99 to 1.02); absolute difference 0.2% (95% confidence interval -0.5% to 0.9%). 99 participants (22.0%) in the virtual care group and 124 (27.3%) in the standard care group required acute hospital care: relative risk 0.80 (0.64 to 1.01); absolute difference 5.3% (-0.3% to 10.9%). More participants in the virtual care group than standard care group had a drug error detected (134 (29.7%) v 25 (5.5%); absolute difference 24.2%, 19.5% to 28.9%) and a drug error corrected (absolute difference 24.4%, 19.9% to 28.9%). Fewer participants in the virtual care group than standard care group reported pain at 7, 15, and 30 days after randomisation: absolute differences 13.9% (7.4% to 20.4%), 11.9% (5.1% to 18.7%), and 9.6% (2.9% to 16.3%), respectively. Beneficial effects proved substantially larger in centres with a higher rate of care escalation. CONCLUSION: Virtual care with RAM shows promise in improving outcomes important to patients and to optimal health system function. TRIAL REGISTRATION: ClinicalTrials.gov NCT04344665.

Mesenchymal stromal cells as a therapeutic intervention for COVID-19: a living systematic review and meta-analysis protocol.

BACKGROUND: Mesenchymal stromal cells (MSCs) have significant immunomodulatory and tissue repair capabilities, mediated partly by conditioned media or through secreted extracellular vesicles (MSC-EVs). Infection with SARS-CoV-2 can cause mild to life-threatening illness due to activated immune responses that may be dampened by MSCs or their secretome. Many clinical studies of MSCs have been launched since the beginning of the global pandemic, however, few have been completed and most lack power to assess efficacy. Repeated systematic searches and meta-analyses are needed to understand, in real time, the extent of potential benefit in different patient populations as the evidence emerges. METHODS: This living systematic review will be maintained to provide up-to-date information as the pandemic evolves. A systematic literature search of Embase, MEDLINE, and Cochrane Central Register of Controlled Trials databases will be performed. All clinical studies (e.g., randomized, pseudorandomized and non-randomized controlled trials, uncontrolled trials, and case series) employing MSCs or their secretome as a therapeutic intervention for COVID-19 will be included. Patients must have confirmed SARS-CoV-2 infection. Study screening and data extraction will be performed in duplicate. Information concerning interventions, patient populations, methods of MSC isolation and characterization, primary and secondary clinical and/or laboratory outcomes, and adverse events will be extracted. Key clinical outcomes will be pooled through random-effects meta-analysis to determine the efficacy of MSCs and their secreted products for COVID-19. DISCUSSION: Our systematic review and subsequent updates will inform the scientific, medical, and health policy communities as the pandemic evolves to guide decisions on the appropriate use of MSC-related products to treat COVID-19. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD 42021225431.

Complications as a Mediator of the Perioperative Frailty-Mortality Association.

BACKGROUND: Preoperative frailty is strongly associated with postoperative complications and mortality. However, the pathways between frailty, postoperative complications, and mortality are poorly described. The authors hypothesized that the occurrence of postoperative complications would mediate a substantial proportion of the total effect of frailty on mortality after elective noncardiac surgery. METHODS: Following protocol registration, the authors conducted a retrospective cohort study of intermediate- to high-risk elective noncardiac surgery patients (2016) using National Surgical Quality Improvement Program data. The authors conducted Bayesian mediation analysis of the relationship between preoperative frailty (exposure, using the Risk Analysis Index), serious complications (mediator), and 30-day mortality (outcome), comprehensively adjusting for confounders. The authors estimated the total effect of frailty on mortality (composed of the indirect effect mediated by complications and the remaining direct effect of frailty) and estimated the proportion of the frailty-mortality association mediated by complications. RESULTS: The authors identified 205,051 patients; 1,474 (0.7%) died. Complications occurred in 20,211 (9.9%). A 2 SD increase in frailty score resulted in a total association with mortality equal to an odds ratio of 3.79 (95% credible interval, 2.48 to 5.64), resulting from a direct association (odds ratio, 1.76; 95% credible interval, 1.34 to 2.30) and an indirect association mediated by complications (odds ratio, 2.15; 95% credible interval, 1.58 to 2.96). Complications mediated 57.3% (95% credible interval, 40.8 to 73.8) of the frailty-mortality association. Cardiopulmonary complications were the strongest mediators among complication subtypes. CONCLUSIONS: Complications mediate more than half of the association between frailty and postoperative mortality in elective noncardiac surgery.

Post Discharge after Surgery Virtual Care with Remote Automated Monitoring Technology (PVC-RAM): protocol for a randomized controlled trial.

BACKGROUND: After nonelective (i.e., semiurgent, urgent and emergent) surgeries, patients discharged from hospitals are at risk of readmissions, emergency department visits or death. During the coronavirus disease 2019 (COVID-19) pandemic, we are undertaking the Post Discharge after Surgery Virtual Care with Remote Automated Monitoring Technology (PVC-RAM) trial to determine if virtual care with remote automated monitoring (RAM) compared with standard care will increase the number of days adult patients remain alive at home after being discharged following nonelective surgery. METHODS: We are conducting a randomized controlled trial in which 900 adults who are being discharged after nonelective surgery from 8 Canadian hospitals are randomly assigned to receive virtual care with RAM or standard care. Outcome adjudicators are masked to group allocations. Patients in the experimental group learn how to use the study's tablet computer and RAM technology, which will measure their vital signs. For 30 days, patients take daily biophysical measurements and complete a recovery survey. Patients interact with nurses via the cellular modem-enabled tablet, who escalate care to preassigned and available physicians if RAM measurements exceed predetermined thresholds, patients report symptoms, a medication error is identified or the nurses have concerns they cannot resolve. The primary outcome is number of days alive at home during the 30 days after randomization. INTERPRETATION: This trial will inform management of patients after discharge following surgery in the COVID-19 pandemic and offer insights for management of patients who undergo nonelective surgery in a nonpandemic setting. Knowledge dissemination will be supported through an online multimedia resource centre, policy briefs, presentations, peer-reviewed journal publications and media engagement. TRIAL REGISTRATION: ClinicalTrials.gov, no. NCT04344665.

A Scoping Review of Registered Clinical Trials of Convalescent Plasma for COVID-19 and a Framework for Accelerated Synthesis of Trial Evidence (FAST Evidence).

Many parallel studies of convalescent plasma with modest enrolment projections have been launched for the treatment of COVID-19. By pooling data from multiple parallel studies that are similar, we can increase the effective sample size and achieve enough statistical power to determine effectiveness more quickly through meta-analysis. A scoping review of registered clinical trials of convalescent plasma for COVID-19 was conducted to assess the feasibility of performing a rapid and timely meta-analysis that will support accelerated review for approval and implementation. ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform were searched April 23, 2020. Trials were included if they utilized convalescent plasma to treat or prevent COVID-19. Forty-eight registered trials (projected to enroll more than 5000 subjects) of convalescent plasma were identified and included for analysis. The majority of studies (33 studies with 4440 projected enrolment) will address the treatment of severe and/or critical cases of COVID-19. Twenty-nine studies are controlled and 17 of these are reported as actively recruiting. The combined enrolment of patients from similar studies should be sufficient to determine meaningful improvements in mortality, rates of admission to intensive care and need for mechanical ventilation by the end of 2020-sooner than any individual study could determine effectiveness. Accessing supplemental outcome data from investigators may be needed; however, to align reporting of some outcomes from these studies. Heterogeneity in product potency due to different antibody titers is anticipated and studies using conventional treatment as controls instead of placebo may complicate our understanding of efficacy. Convalescent plasma is being tested in ongoing controlled studies, largely to treat severe and/or critical cases of COVID-19. Sufficient combined power to detect clinically important reductions in multiple outcomes, including mortality, is expected by September 2020. Regulatory approval, funding and implementation by blood operators could be accelerated by planned meta-analysis as study results become available.

A Scoping Review of Registered Clinical Trials of Cellular Therapy for COVID-19 and a Framework for Accelerated Synthesis of Trial Evidence-FAST Evidence.

The urgent need for safe and effective treatments for COVID-19 has fueled the launch of many parallel complex studies of cellular therapies with small to modest enrolment projections. By pooling data from multiple studies that are similar, we can increase the ability to achieve sufficient power to determine effectiveness more quickly through meta-analysis. A scoping review of registered clinical trials using cell-based interventions for COVID-19 was conducted to identify candidate studies for meta-analysis that could support an accelerated regulatory review. ClinicalTrials.gov and WHO International Clinical Trials Registry Platform were searched April 23, 2020. Trials were included if they utilized cell or cell-derived products to treat or prevent COVID-19. Fifty-four registered cellular therapy trials were identified and included for analysis. Studies of mesenchymal stromal cells (MSCs; 41 studies; 1129 subjects projected to receive cells) and natural killer (NK) cells (5 studies; 135 projected to received cells) were observed most commonly. A subset of studies are controlled (34 studies, or 63%), including 27 studies of MSCs and 3 of NK cells. While heterogeneity in study design exists, the cumulative projected enrolment of patients from similar studies appears sufficient to allow the detection of meaningful differences in clinically important outcomes such as mortality, admission to intensive care and need for mechanical ventilation by September 2020-sooner than any individual study could determine effectiveness. MSCs are the predominant cell type in registered trials for severe or critical COVID-19 and represent the most promising candidates for future meta-analysis. Sufficient pooled sample size to detect clinically important reductions in multiple outcomes, including mortality, is anticipated by September 2020, but may require accessing supplementary data to align outcome reporting. Regulatory approval, funding and implementation by cell manufacturing partners will be accelerated by our framework for rapid meta-analysis.