Novel Hertz Contact Intravascular Lithotripsy: Could We Achieve More in Balloon-Based Calcium Modification?

Severe coronary artery calcification (CAC) remains a major challenge in percutaneous coronary intervention (PCI), driving stent under-expansion and higher rates of restenosis and adverse events. Balloon-based calcium modification remains central to lesion preparation, with the available tools ranging from high-pressure non-compliant balloons and ultra-high-pressure balloons to cutting, scoring, and intravascular lithotripsy (IVL) balloons. While traditional IVL has advanced the field by permitting circumferential fracture of deep calcium through acoustic shockwaves, important drawbacks persist, including problems in deliverability, energy distribution, and questionable efficacy in nodular or eccentric calcium. This review examines all contemporary balloon-based modification strategies and introduces the novel Hertz-contact IVL (HC-IVL), a new technology designed to transmit mechanical energy through direct contact rather than shockwave propagation. Based on Hertzian mechanics, this device may facilitate more focused energy delivery, improved lesion crossing, and enhanced calcium fracture in complex morphologies. A detailed comparison between HC-IVL and standard IVL is provided, along with a proposed algorithm for device selection. Taking into consideration the limitations of current tools, HC-IVL represents a promising mechanistic innovation in balloon-based calcium modification, warranting further validation in randomized, imaging-guided clinical studies.