Cutting balloon versus standard balloon for lesion preparation of drug-coated balloon treatment in de-novo coronary artery lesions: Rationale and design of the randomized NATURE trial

Background Drug-coated balloons (DCBs) have emerged as an alternative to drug-eluting stents (DESs) for percutaneous coronary intervention (PCI) in de novo coronary artery diseases (CADs). However, the optimal predilatation strategy prior to DCB dilatation has yet to be validated. Methods/design The NATURE ( N on-stent PCI with an a ppropriate dila t ation by means of c u tting balloon and d r ug-coated balloon in de novo l e sion) study is a prospective, multi-center, randomized controlled trial designed to evaluate the safety and efficacy of a cutting balloon compared to standard balloons (semi-compliant or non-compliant balloons) for lesion preparation prior to DCB treatment in normal-sized vessels. The DCB treatment is performed with the guidance of intravascular ultrasound (IVUS) and fractional flow reserve (FFR). The study will enroll 200 patients with a single de novo coronary lesion (reference vessel diameter: 2.5–4.0 mm) at 18 sites. Patients are randomized 1:1 to undergo predilatation with either a cutting or standard balloons, followed by DCB dilatation. The primary endpoint is the success rate of optimal predilatation, as defined by the International DCB Consensus Group: no flow-limiting dissections, residual stenosis ≤30 %, and FFR >0.80. Secondary endpoints include in-segment late lumen loss (LLL) at 9 months, the incidence of bailout stenting, and clinical outcomes at 6 and 12 months. Summary The NATURE study aims to address the critical gap in evidence regarding optimal predilatation for DCBs in de novo CADs. By utilizing state-of-the-art DCB treatment strategies, including cutting balloons, intravascular imaging, and physiological tools, this study is expected to provide meaningful insights for refining DCB-based PCI strategies. Clinical Trial Registration URL: https://jrct.niph.go.jp/ . Unique Identifier: jRCTs032230543.