Adjunctive optical and magnetic stimulation for venous and mixed etiology leg ulcers: protocol for the NAZARÉ multicenter randomized controlled trial

Abstract Background Venous leg ulcers (VLUs) and VLUs associated with peripheral arterial disease (PAD) are common, recurrent, and costly to manage. Adjunctive biophysical therapies may improve healing outcomes when combined with standard of care (SOC). Concurrent optical and magnetic stimulation (COMS) has shown promising mechanistic and preliminary clinical results but there is a lack of robust randomized controlled trials (RCTs). Method This novel adjunct using concurrent optical and magnetic stimulation in a multicenter RCT in Europe (NAZARÉ) is a phase IV, post-market, multicenter, parallel-group, superiority randomized controlled trial conducted in Switzerland, France, Germany, and Austria. A total of 122 adults with VLU or mixed leg ulcers (ankle-brachial index > 0.5 and < 1.30 or ankle artery pressure > 60 mmHg), ulcer area 2–50 cm 2 , and ulcer duration > 30 days and < 2 years will be enrolled. Following a 2-week run-in to confirm < 30% area reduction under SOC, participants will be randomized 1:1 to SOC + COMS or SOC alone. The primary outcome is percentage wound area reduction (PWAR) at week 12, assessed by blinded evaluators using standardized digital planimetry. Secondary outcomes include complete closure, time-to-healing, pain, health-related quality of life, recurrence, and healthcare resource use. Missing outcome data will primarily be analyzed as observed and may be addressed using multiple imputation under the assumption of data being missing at random. Discussion This trial will rigorously assess the effectiveness of COMS as an adjunct to standard care for venous and mixed leg ulcers. By targeting chronic wounds and using a pragmatic, multicenter design, it aims to generate robust, generalizable evidence. If effective, COMS could offer a non-invasive, accessible option to enhance healing outcomes and reduce the burden of chronic leg ulcers. Trial registration number ClinicalTrials.gov NCT06528873. Registred on 26 July 2024, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?selectaction=Edit&sid=S000ERKB&uid=U0003LG4 .