Intravascular Lithotripsy for the Treatment of Calcium-Mediated Coronary In-Stent Restenoses.

BACKGROUND Coronary intravascular lithotripsy (IVL) has recently been evaluated for the treatment of severely calcified native coronary lesions. Evidence for its use in in-stent restenosis is sparse and is still an off-label indication. Therefore, we aimed to evaluate the feasibility, safety, and acute and mid-term angiographic outcomes after IVL for the treatment of calcium-mediated coronary in-stent restenosis. METHODS A retrospective, single-center analysis was performed for 6 cases with undilatable instent restenosis due to calcium-mediated stent underexpansion and/ or calcified neointima from January to November 2019. Lesions were treated with IVL (Shockwave Medical) and subsequent drug-eluting stent or drug-coated balloon. Angiographic success was defined as residual lumen stenosis <20% and Thrombolysis in Myocardial Infarction 3 flow. Follow-up angiography was performed at a median of 141.5 days. RESULTS Six patients presented with symptomatic in-stent restenoses (65.8% to 87.9%) at 11 to 175 months after implantation. Intravascular and angiographic imaging detected calcium-mediated stent underexpansion (n = 2), calcified neointima (n = 2), or a combination of both (n = 2) as cause of restenosis. In-stent IVL, subsequent high-pressure balloon dilation, and drug-eluting stent or drug-coated balloon implantation were performed successfully in all cases. Acute angiographic success and angina relief were achieved in 5 of 6 cases and sustained during follow-up. No major acute cardiovascular events occurred. CONCLUSIONS The application of IVL for the treatment of calcium-mediated coronary in-stent restenosis was feasible and safe, and yielded promising short- and mid-term results in the majority of cases.