Duchenne and Becker muscular dystrophies (DMD and BMD) are devastating conditions characterised by progressive muscle degeneration and weakness. Despite advances in understanding their pathogenetic processes, there is a critical need for reliable biomarkers to aid in patient stratification and inform clinical decision-making, predict disease progression and evaluate therapeutic responses. Several promising protein biomarkers have been investigated as potential diagnostic/prognostic tools, but, to date, this evidence has not been systematically synthesised. We aim to comprehensively and critically review and summarise published studies reporting the use of protein signatures of muscular damage in DMD and BMD.

We will systematically search Ovid MEDLINE (PubMed), OVID Embase, OVID Evidence-Based Medicine Reviews and Cochrane Library to retrieve all relevant articles. For ongoing trials, we will search WHO International clinical trials registry and ClinicalTrials.gov registry. We will include studies that measure circulating and urine levels of established and/or promising protein biomarkers associated with skeletal muscular damage and disease progression, such as creatine kinase, myoglobin, skeletal troponin I fast-twitch (type II), myostatin, creatine/creatinine ratio, creatinine and titin. We will consider randomised controlled trials, observational studies and longitudinal cohort studies with serial sampling, without restrictions on sample size, geographic location or language, while excluding animal and in vitro studies. Two independent reviewers will screen articles for inclusion using predefined eligibility criteria and extract data of retained articles. A third author will be consulted in case of disagreement. The approach recommended by the Agency for Healthcare Research and Quality’s Methods Guide for Effectiveness and Comparative Effectiveness Reviews will be used. The risk of bias and reporting quality will be assessed with standardised scales. The analysis will involve a structured narrative synthesis and evidentiary tables. If a meta-analysis is possible, biomarker data for each outcome will be pooled using random effects models. Subgroup analyses have been planned as a function of age, genetic mutation, disease severity, imaging and clinical assessment, length of the observation and risk of bias.

Ethics approval is not required for this study as no original data will be collected. The findings will be shared through peer-reviewed publications and conference presentations. Additionally, this systematic review will guide the recommendations of the Duchenne Regulatory Science Consortium. This work will provide a rigorous, exhaustive and accessible evidence synthesis to identify candidate biomarkers of potential clinical value. Furthermore, it is expected that these results could be used to facilitate the development of future research strategies and guidelines, inform resource allocation decisions and accelerate the route towards clinical implementation of biomarkers for DMD and BMD.

CRD42024549471. Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024549471

Postoperative pulmonary complications (PPCs) are common after cardiac surgery and are associated with significant morbidity and mortality. Lung-protective ventilation strategies have been proposed to reduce PPCs, but the optimal level of positive end-expiratory pressure (PEEP) and the use of alveolar recruitment manoeuvres (RMs) remain controversial.

In this investigator-initiated, multicentre, open, randomised, parallel-group, superiority clinical trial, elective cardiac surgery patients at risk of PPCs will be assigned to one of two intraoperative ventilation strategies: (1) an open-lung ventilation strategy with protective ventilation, moderate PEEP and RMs or (2) a standard protective ventilation with low PEEP and no RM. The primary outcome will be a composite of prolonged (>24 hour) postoperative mechanical ventilation, reintubation for any cause or hospital-acquired pneumonia within 7 days of surgery, or death within 28 days of surgery. Data will be analysed on an intention-to-treat basis.

The VACARM (impact of intraoperatiVe moderAte positive end-expiratory pressure with reCruitment mAnoeuvres versus low positive end-expiRatory pressure on major postoperative pulMonary complications and death after on-pump cardiac surgery in high-risk patients) trial has been approved by an independent ethics committee for all study centres. Recruitment began in July 2021. Results will be published in international peer-reviewed medical journals.

ClinicalTrials.gov NCT04408495.