Suboptimal efficacy of intravascular lithotripsy in severe calcified in-stent restenosis: Insights from a case report and the role of intravascular imaging guidance

Intravascular lithotripsy (IVL) is increasingly utilized for the management of severe coronary artery calcification, including in-stent restenosis (ISR). However, its efficacy in complex ISR, particularly with end-stage renal disease complicated by stent underexpansion and high calcium burden, remains unclear. We present the case of a 75-year-old hemodialysis patient with severe calcification and recurrent ISR involving the left main and left circumflex (LCX) arteries. The initial percutaneous coronary intervention employed IVL with undersized balloons (2.5 mm in LCX; 3.5 mm in left main) and was completed with a drug-eluting balloon in the LCX, without achieving adequate lesion preparation. We critically analyze the rationale behind this approach and its inherent limitations. While IVL achieved effective stent expansion in the left main, postprocedural optical coherence tomography demonstrated persistent severe calcification and underexpansion in the LCX (minimal stent area: 2.39 mm²), which resulted in recurrent symptomatic non-ST-elevation myocardial infarction within 6 months. This case underscores several critical lessons: (1) IVL may be ineffective in heavily calcified ISR, especially when calcium underlying underexpanded stent struts is not adequately modified and with inadequate balloon sizing; (2) Preintervention intravascular imaging is indispensable for characterizing calcium and guiding therapy selection; and (3) Suboptimal lesion preparation, including the avoidance of debulking strategies such as atherectomy in high-risk scenarios, can lead to poor outcomes. This case underscores the limitations of IVL in such complex clinical scenarios and strongly advocates for an intravascular imaging-guided paradigm involving meticulously planned lesion preparation, which may include a low threshold for considering atherectomy-based debulking strategies.