Intravascular Lithotripsy for the Treatment of Severely Calcified Coronary Artery Disease: A DISRUPT CAD III Intravascular Ultrasound Substudy

Background: Coronary intravascular lithotripsy (IVL) has emerged as a novel technique for the treatment of severely calcified coronary lesions. We evaluated the mechanism and efficacy of IVL in facilitating optimal stent implantation in heavily calcified coronary lesions using intravascular ultrasound (IVUS). Methods: Forty-six patients were initially enrolled as a part of the Disrupt CAD III study. Of these, 33 had pre-IVL, 24 had post-IVL, and 44 had post-stent IVUS evaluation. The final analysis was performed on 18 patients who had IVUS images interpretable at all three intervals. The primary endpoint was increase in minimum lumen area (MLA) from pre-IVL to post-IVL treatment to post-stenting. Results: Pre-IVL, MLA was 2.75 ± 0.84 mm², percent area stenosis was 67.22 % ± 20.95 % with maximum calcium angle of 266.90° ± 78.30°, confirming severely calcified lesions. After IVL, MLA increased to 4.06 ± 1.41 mm² (p = 0.0003), percent area stenosis decreased to 54.80 % ± 25.71 % (p = 0.0009), and maximum calcium angle decreased to 239.40° ± 76.73° (p = 0.003). There was a further increase in MLA to 6.84 ± 2.18 mm² (p < 0.0001) and decrease in percent area stenosis to 30.33 % ± 35.08 % (p < 0.0001) post-stenting with minimum stent area of 6.99 ± 2.14 mm². The success rate of stent delivery, implantation, and post-stent dilation was 100 % post-IVL. Conclusion: In this first study evaluating the mechanism of IVL using IVUS, the primary endpoint of increase in MLA from pre-IVL to post-IVL treatment to post-stenting was successfully achieved. Our study showed that the use of IVL-assisted percutaneous coronary intervention is associated with improved vessel compliance, facilitating optimal stent implantation in de novo severely calcified lesions.