Advances in Drug-Eluting Angioplasty Balloon Coatings, Clinical Implications and Future Directions: A Mini Review.

Drug-eluting angioplasty balloons are a highly effective treatment for neointimal hyperplasia post-balloon angioplasty and in-stent restenosis. Current drug-eluting angioplasty balloons have restenosis rates approximating 20%, and both paclitaxel, the current drug coating of choice, and sirolimus, an alternative coating being evaluated in early clinical studies, delay re-endothelialisation, potentially predisposing to thrombosis. There remains a paucity of efficacious alternatives to these coatings. Research into alternative drug-eluting balloon coatings is the source of intense investigation in attempts to improve on efficacy and safety of this highly effective therapeutic intervention. We discuss recent clinical developments with regard to sirolimus drug-coated balloons, demonstrating efficacy in early studies in relation to coronary, peripheral arterial, and renal access applications. However, limited comparator studies with paclitaxel currently exist. In addition, we explore novel drug-eluting angioplasty balloon coatings currently under evaluation in the preclinical space, together with associated molecular mechanisms of action. Further in vivo evaluation of these potential alternative coatings is required, and an algorithm to support the rational evaluation of novel coatings and their subsequent clinical development has been provided.