Coronary Drug-Coated Balloons as Brief-Contact Drug-Delivery Platforms: Engineering, Tissue Pharmacokinetics, and Angiographic/Imaging Response

Background and Objectives: Coronary drug-coated balloons (DCBs) deliver antiproliferative therapy during a single inflation without leaving a permanent scaffold or implanted drug reservoir. Their performance therefore depends on preservation of the coating during delivery, efficient vessel-wall transfer, and sufficient tissue exposure after balloon removal. This review critically examines the evidence for platform engineering, tissue exposure, and angiographic or intravascular imaging response. Materials and Methods: This narrative review synthesized English-language experimental, pharmacokinetic, imaging, and clinical evidence identified through the original PubMed, Scopus and Google Scholar searches and a documented PubMed search during revision on 9 September 2026. Exact queries, record dispositions and descriptive study appraisals are supplied; conference abstracts, preprints and unpublished data were excluded. Results: DCB performance is platform-specific rather than determined by drug class alone. Within both paclitaxel- and limus-based devices, excipient chemistry, coating or carrier architecture, release behavior, and retention strategy may influence drug delivery. Bench and computational studies identify potential transfer and drug-loss pathways, pharmacokinetic studies measure tissue exposure, and imaging and clinical studies assess morphology and outcomes separately. The cited human studies do not quantify coronary tissue drug exposure. Findings from unrelated platforms and models cannot establish a causal delivery-to-outcome pathway. Conclusions: Coronary DCBs should be evaluated as integrated, device-specific drug-delivery platforms. Standardized studies linking engineering performance and tissue exposure with imaging and clinical outcomes are needed.