Intravascular ultrasound characterisation of intravascular lithoplasty for treatment of coronary calcified lesions

Background Intravascular lithotripsy (IVL) is an efficient and emerging calcification modifying technique with a short learning curve and few complications. Methods We analyzed intravascular ultrasound (IVUS) findings in 412 patients in whom has a severe coronary calcification and a clinical indication for vessel preparation with IVL. The efficacy outcome was procedural success (defined as residual area stenosis <30%, without interventional complications or in-hospital MACE). Results The mean age was 67.40 ± 9.37 years, and 71.4% were males. The most common target lesion was the LAD, 19.2% lesions was chronic total occlusion, and 8.7% lesions were in-stent restenosis. Patients underwent IVUS examinations before IVL and after PCI. The average area stenosis was 72.18 ± 7.40 %, and pre-MLD was 1.44 ± 0.19 mm. The average calcification length was 29.84 ± 11.24 mm, 7.5% of lesions has calcified nodule, and calcified plaque burden was 59.93 ± 5.54%. The calcified rings fractured after IVL treatment, with a median of 4 (3, 4) fractured sites. The acute lumen gain was 1.15 ± 0.27mm, the post-MLD was 2.59 ± 0.22 mm, and residual area stenosis was 22.06 ± 9.49 %. The IVUS measurements of pre-IVL and post-PCI were compared. After procedure, the MLD (2.56(2.45, 2.74) mm vs. 1.42(1.30, 1.56) mm, p<0.001) and MLA (5.93(5.41, 6.54) mm2vs. 2.04(1.75, 2.52) mm2, p<0.001) were significantly improved, and area stenosis was significantly reduced (24.00(15.25, 28.00) % vs. 74.00(68.00, 77.00) %, p<0.001). Regarding the plaque burden, compared to pre-IVL, the max plaque thickness (0.68(0.64, 0.72) mm vs, 0.90(0.86, 0.95) mm, p<0.001) and the plaque burden (48.17 (45.48, 50.47) % vs. 59.72(56.06, 63.47) %, p<0.001) of post-PCI was significantly reduced. Regarding the efficacy outcome, 93.4% of patients achieved proceduresuccess, and only 4 patients (1.0%) experienced complications during PCI and 1 patient (0.2%) experienced in-hospital MACE. Conclusions IVL treatment is a safe and effective calcification modifying technique for severe coronary calcified lesions, which can fragment the calcified ring and provide efficient pretreatment for subsequent stent implantation.Lesion Characteristics and PCI Outcomes.For image description, please refer to the figure legend and surrounding text.Comparison of Pre-IVL and Post-PCI on IVUS.