To compare the angiographic and clinical outcomes of aggressive versus standard balloon preparation during drug-coated balloon (DCB) angioplasty for in-stent restenosis (ISR). The study will evaluate whether more aggressive lesion preparation with cutting/scoring/OPN balloons improves outcomes compared to standard preparation with semi-compliant or non-compliant balloons.

PICCOLETO XI A-PREP is an investigator-initiated, multicenter, international, observational study evaluating the impact of lesion preparation strategies on outcomes following drug-coated balloon (DCB) angioplasty for in-stent restenosis (ISR).

In-stent restenosis remains a clinically relevant challenge despite advances in drug-eluting stent technology and contemporary percutaneous coronary intervention techniques. DCB represents a stentless therapeutic strategy for ISR treatment, with the advantage of avoiding implantation of additional metallic layers.

A key determinant of clinical outcomes in ISR, particularly with DCB angioplasty, is the adequacy of lesion preparation before definitive therapy. Effective preparation facilitates optimal drug delivery, improves luminal gain, and may reduce the risk of recurrent restenosis.

A large spectrum of balloon-based modalities is available for ISR lesion preparation, ranging from semi-compliant and non-compliant balloons to more aggressive tools such as scoring and cutting balloons. Although more aggressive devices may enhance plaque modification and neointimal tissue disruption, their incremental clinical benefit over standard approaches remains uncertain.

Patients will be categorized into two groups based on lesion preparation strategy:

• Aggressive preparation: Cutting/Wolverine balloons, scoring balloons (any brand), and/or OPN balloons
• Standard preparation: Semi-compliant balloons and/or non-compliant balloons

Clinical outcomes will be assessed at 1-year and longest available follow-up.

Inclusion Criteria:

• Adult patients ≥18 years of age
• Patients who underwent DCB angioplasty for in-stent restenosis

Exclusion Criteria:

- Lack of clinical outcome assessment

Adult patients who underwent drug-coated balloon (DCB) angioplasty for in-stent restenosis (ISR) at participating centers.

Individual participant data may be made available to qualified researchers upon reasonable request after study completion and primary publication, subject to appropriate data use agreements and ethics committee approval.