Sirolimus-coated balloon versus everolimus-eluting stent in de novo coronary artery disease: Rationale and design of the TRANSFORM II randomized clinical trial.

Background: Percutaneous coronary intervention (PCI) with drug-eluting stent (DES) implantation is a widely adopted strategy for the treatment of de novo coronary artery disease. DES implantation conveys an inherent risk for short- and long-term complications, including in-stent restenosis and stent thrombosis. Drug-coated balloons are emerging as an alternative approach to fulfill the "leaving nothing behind" principle and avoid long-term DES-related complications.

Design: TRANSFORM II is an investigator-initiated, multicenter, noninferiority, randomized clinical trial, testing a sirolimus-coated balloon (SCB) versus the standard of care for native coronary vessels with a 2-3 mm diameter, in terms of 12-month target lesion failure (TLF; primary endpoint) and net adverse cardiovascular events (coprimary endpoint). Patients undergoing PCI will be randomized to be treated with either SCB or new-generation everolimus-eluting stent and will be followed up clinically for up to 60 months. Assuming a TLF rate of 8% at 12 months with DES, a sample size of 1325 patients was chosen to ensure an 80% power to detect a 1.5% lower incidence in the SCB group with a type I error rate of 0.05. The TRANSFORM II trial is registered on clinicaltrials.gov (identification number NCT04893291). Several substudies, including an optical coherence tomography assessment at 9 months (intracoronary imaging substudy), will investigate the study device in different clinical and lesion settings.

Conclusions: The randomized TRANSFORM II trial will determine whether a novel SCB is noninferior to a current everolimus-eluting stent when adopted for the treatment of de novo lesions in coronary vessels with a diameter between 2 and 3 mm.