Severely calcified coronary stenoses are difficult to treat with percutaneous coronary intervention (PCI) using current techniques. Severe calcifications make it difficult to sufficiently prepare lesions before stenting, to advance stents, and to achieve full stent expansion. There is increased risk of vessel dissection and perforation with angioplasty on severely calcified lesions, and long-term outcomes of PCI are adversely affected. Because severely calcified lesions are often excluded from interventional studies, there is little specific evidence on how to best treat these cases. Only a few randomized studies have specifically explored this question, focusing on the use of rotational atherectomy

Recently, the technique of balloon-based lithoplasty was made commercially available. With this technique, calcifications are cracked with the creation of high-frequency pressure oscillations in a special angioplasty balloon. Standard techniques are used to deliver and dilate the balloon. The method was developed for treatment of otherwise non-dilatable lesions, and first reported results have been encouraging. The lithoplasty device used in the current study (Shockwave IVL, Shockwave Medical, CA, USA) has received CE-mark and post-approval safety has recently been confirmed for treatment of severely calcified coronary lesions in patients.

Besides obvious benefits in non-dilatable lesions for which interventional cardiologists have few other options, it is possible this technique could change the way all severely calcified lesions are treated. Balloon lithoplasty could theoretically crack plates of calcium in the vessel wall in an orderly fashion, which could lead to safer and quicker preparation of severely calcified lesions. Furthermore, a better softening of vessel wall calcium could allow full and symmetric expansion of coronary stents, which could lead to better long-term stent patency.