Atrial Fibrillation (AF) is the most common arrhythmia worldwide affecting an estimated 5% of people over the age of 65 and is a leading cause of stroke and heart failure. Identification of patients at risk allows preventative measures and treatment before these complications occur. Conventional risk prediction models are static, do not have flexibility to incorporate dynamic risk factors and possess only modest predictive value. Artificial intelligence and machine learning-powered health virtual twin technology offer transformative methods for risk prediction and guiding clinical decisions.

In this prospective observational study, 1200 patients will be recruited in two tertiary centres. Patients hospitalised with acute illnesses (sepsis, heart failure, respiratory failure, stroke or critical illness) and patients having undergone high-risk surgery (major vascular surgery, upper gastrointestinal surgery and emergency surgery) will be monitored with a patch-based remote wireless monitoring system for up to 14 days. Clinical and electrocardiographic data will be used for modelling the risk of new-onset AF. The primary outcome is episodes of AF >30 s and will be described as ratio of episodes/patient and as percentage of patients having episodes of AF. Secondary outcomes include 30-day and 90-day readmission rates and complications of AF.

The aim of this study is to generate data for the development and validation of health virtual twins predicting onset of AF in an at-risk population. The intelligent monitoring to predict atrial fibrillation (NOTE-AF) study is part of the TARGET project, a Horizon Europe funded programme which includes risk prediction, diagnosis and management of AF-related stroke (https://target-horizon.eu/).

The study has received approval by the Health Research Authority and the National Research Ethics Service (REC reference 24/NW/0170, IRAS project ID: 342528) in the UK and has been registered on clinicaltrials.gov (NCT06600620). Results will be disseminated as outlined in the TARGET protocol to communicate project ideas, activities and results to diverse audiences.

NCT06600620.

Over the past decades, interest in second breast-conserving therapy (BCT) has increased due to, among others, advances in radiotherapy techniques. Preoperative partial breast irradiation (PBI) is an experimental treatment for patients with low-risk primary breast cancer. This approach can downstage the tumour and may possibly reduce toxicity and improve cosmetic outcomes compared with postoperative radiotherapy. This study aims to evaluate the feasibility of single-dose preoperative PBI and second breast-conserving surgery (BCS) for patients with an ipsilateral recurrent breast event (IRBE) after previous BCT.

The REPEAT trial is a multicentre, prospective, single-arm trial investigating ablative single-dose preoperative PBI in patients with an IRBE. Eligible patients are ≥50 years, have a unifocal non-lobular invasive breast cancer ≤2 cm, Bloom-Richardson grade 1 or 2, oestrogen receptor-positive, human epidermal growth factor receptor 2-negative and clinically negative axillary lymph nodes. The study plans to enrol 25 patients. Radiotherapy planning will involve the use of CT and MRI in the treatment position. Single-dose PBI of 20 Gy to the tumour and 15 Gy to the surrounding 2 cm of breast tissue will be delivered using a conventional or MR-guided linear accelerator. Tumour response will be monitored preoperatively using MRI and liquid biopsies to identify biomarkers for evaluating radiosensitivity. BCS will be performed 3 (±one) weeks post PBI. The primary endpoint is the incidence of grade 2 or higher treatment-associated acute toxicity within 90 days. Secondary endpoints include the evaluation of acute (grade 1) and late toxicity, radiologic and pathologic response, mastectomy rate, patient-reported outcomes, cosmetic outcome, local, regional and distant recurrence rates, survival outcome and biomarkers in liquid biopsies and tumour tissue. Patients will be followed up to 5 years after PBI.

Ethical approval from the Medical Research Ethics Committee of the Amsterdam UMC has been obtained (NL85983.018.24). The results will be disseminated via peer-reviewed academic journal and presentation at conferences. In addition, summaries will be shared with the participating patients.

The trial was registered prospectively on October 11^th 2024 at clinicaltrials.gov (NCT06640881).