State of the art: evolving concepts in the treatment of heavily calcified and undilatable coronary stenoses - from debulking to plaque modification, a 40-year-long journey.

Since the first balloon angioplasty by Andreas Grüntzig 40 years ago, interventional cardiology has witnessed the introduction of countless tools and techniques that have significantly contributed to broadening the application of percutaneous coronary interventions (PCI) in unprecedented anatomic settings. Heavily calcified, fibrotic coronary stenosis has traditionally represented a very challenging scenario for PCI, and a very common indication for surgical revascularisation. This was mostly due to the difficulty in adequately dilating these lesions and/or to the inability to deliver and implant stents appropriately, which is often associated with high rates of procedural complications and suboptimal long-term clinical outcomes. Thanks to dedicated cutting and scoring balloons and to atherectomy devices, the treatment of most fibrotic and heavily calcified stenoses has become feasible and safe. Interventional cardiologists have learned how best to apply these tools through better patient and lesion selection, and also as a result of improved technology and techniques. In this review, we describe a 40-year-long journey that has evolved from the initial stand-alone debulking strategy to the currently applied coronary plaque modification, with the main objective of optimising drug-eluting stent delivery and implantation, translating into significantly improved patient outcomes.