Drug-eluting balloons: effective and durable treatment for in-stent restenosis.

The introduction of percutaneous transluminal coronary angioplasty (PTCA) by Andreas Gruentzig was a game changer for coronary revascularization (1). However, PTCA is associated with significant rates of acute closure and restenosis resulting from vascular recoil, neointimal hyperplasia, and negative remodeling. Bare-metal stents (BMS) effectively treat acute closure and limit restenosis by preventing vascular recoil and negative remodeling (2). With widespread adoption of BMS emerged in-stent restenosis (ISR), a lesion resulting from aggressive smooth muscle cell proliferation and extracellular matrix production that has been significantly reduced by drug-eluting stents (DES). Nevertheless, both BMS and DES are deployed for patient and lesion specific reasons and hence ISR is not uncommonly encountered in clinical practice. Furthermore, ISR may present as unstable angina (16% to 66%) or myocardial infarction (1% to 20%) and therefore continues to be a significant limitation of contemporary percutaneous coronary intervention (3–5).