Severely calcified coronary lesions represent one of the major challenges in interventional cardiology. Severe coronary calcification increases the difficulty and complexity of percutaneous coronary intervention (PCI), impedes device delivery, and may even lead to device failure. Moreover, stent underexpansion further elevates the risks of cardiac death, myocardial infarction, target vessel revascularization, and in-stent thrombosis. Rotational atherectomy (RA) is an effective modality for treating severely calcified coronary lesions, as it adequately modifies calcific plaques, facilitates luminal enlargement, and improves device deliverability. However, RA fragments calcific plaques into microparticles that are subsequently cleared by the reticuloendothelial system in the distal microvasculature, potentially inducing microvascular dysfunction.

In recent years, intravascular lithotripsy (IVL) has emerged as an innovative calcium-modification technique in clinical practice. This technology employs acoustic pressure waves to selectively disrupt deep-seated calcific plaques, inducing fractures within the calcium while sparing the soft tissue of the vessel wall from substantial injury. IVL is performed with low-pressure balloon inflation (4-6 atm), which helps to minimize the risk of vascular injury; its mechanism of action does not produce macroscopic debris, theoretically obviating distal embolization and associated microcirculatory disturbances. Recently published prospective observational studies-the REPLICA-EPIC18 and BENELUX-IVL registries-have demonstrated that IVL is feasible and safe in "real-world" severely calcified lesions, effectively facilitating stent implantation.

Although both RA and IVL are important tools for managing severe calcific lesions, there remains a paucity of high-level, head-to-head evidence directly comparing post-procedural minimal stent area between the two modalities. Clarifying this issue is of significant clinical importance for guiding clinicians in selecting optimal revascularization strategies tailored to distinct pathological characteristics and patient profiles, thereby improving procedural safety and patient outcomes. To this end, we plan to conduct a prospective, multicenter, randomized clinical trial (RCT) aimed at comparing the minimal stent area between intravascular lithotripsy and rotational atherectomy in patients with severely calcified lesions.