Coronary Compliance Modification by Intravascular Lithotripsy: New Predictor of Stent Expansion in Calcified Coronary Lesions

Background Intravascular lithotripsy ( IVL) has been demonstrated to be effective in treating balloon-crossable calcified coronary lesions by inducing calcium fractures and facilitating stent expansion (SE), theoretically by improving coronary artery compliance (CACom). Direct evidence of this theory has not yet been provided. Methods From the BENELUX-IVL prospective registry (NCT06577038) enrolling patients with calcified coronary artery lesions treated with IVL, intravascular ultrasound–guided cases were selected. CACom was calculated as the systo-diastolic change in the luminal area (ΔA), measured using intravascular ultrasound, relative to the corresponding change in aortic pressure (ΔP). Measurements were taken directly before (pre-CACom) and after (post-CACom) IVL therapy at the most calcified segment, where IVL pulses were administered. The primary end point was CACom modification (ΔCACom), defined as post-CACom – pre-CACom, with a correlation analysis between ΔCACom and new fractures as a key exploratory aim. Secondary analysis included assessing whether ΔCACom could predict SE at the minimum stent area (MSA) and the eccentricity index. Results Coronary artery compliance significantly improved after IVL therapy (median ΔCACom 0.33 [0.19-0.70] mm 2 /mm Hg; P < .01). Lesions showing new calcium fractures presented significantly greater ΔCACom compared to those without. ΔCACom and new calcium fractures were significantly correlated (R = 0.466; P < .01). In univariate analysis, ΔCACom was found to be a significant predictor for SE at MSA ( P < .01), MSA ( P = .015), and SE >80% ( P = .025), but not eccentricity index ( P = .157). At multivariate analysis, ΔCACom was an independent predictor of SE (R = 0.420; P = .044) and SE >80% at MSA (OR, 6.58 [1.24-34.90]; P = .043). Conclusions In heavily calcified coronary lesions treated with IVL, ΔCACom is an independent predictor of SE.