Implications of calcified nodule and adjacent calcification severity for target lesion revascularization after percutaneous coronary intervention: multi-center intravascular ultrasound imaging study

Abstract Background Calcified nodule (CN) is a distinct plaque phenotype, characterized as protruding nodular calcification penetrating lumen surface with the attached thrombus. Recent studies revealed that a risk of repeat revascularization after PCI was substantially elevated in patients with coronary artery disease (CAD) attributable to CN. Furthermore, pathohistological studies have elucidated mechanistic insights into the formulation and progression of CN, suggesting that it is formulated by the fracture of sheet calcification at its adjacent segment. Purpose To elucidate the association of calcified plaque volume at CN and adjacent lesions with TLR risks in CAD patients receiving PCI by using IVUS imaging. Methods This multicenter study analyzed IVUS imaging at culprit segment was conducted in 204 CAD patients attributable to de novo CN receiving PCI. The calc grade was assigned at each 1-mm cross-sectional frame of CN and culprit segment, respectively (no calc=0, 1-89°=1, 90-179°=2, 180-269°=3, 270-360°=4). Calcium Volume Index (CVI) at both CN and adjacent zone were calculated (Figure; Calcification volume index at CN zone = the sum of calcium scores at CN・averaged lesion slices of CN / CN lesion slices, Calcification volume index at adjacent zone = the sum of calcium scores at adjacent zone・averaged lesion slices of adjacent zone / adjacent zone slices). Predictors of TLR were analyzed by multivariate Cox hazard model. Results CN was successfully treated by DES (82%) and DCB (18%). 34% and 8.3% of subjects required rotablator and orbital atherectomy, respectively. Consequently, final lumen area after PCI was 7.2 ± 0.4 mm2. During the 2.8-year observational period (interquartile range: 2.4 to 3.2 years), TLR was required in 63 patients (30.9%) of study population. CVI at CN and adjacent zone were 9.9 ± 0.4 and 7.0 ± 0.7, respectively. On multivariate analysis, hemodialysis, final lumen area, CVI at both CN and adjacent zone predicted TLR (Figure). Recurrent TLR (two or more TLRs) was found in 23.3% patients who suffered from TLR. Of note, even among patients who required TLR, CVIs at both zones were significantly higher in patients with recurrent TLR than those without (Figure). Conclusion CAD subjects caused by CN exhibited a considerably high-risk TLRs. Our findings underscore that calcification severity at both CN and adjacent segment predicted TLR and is associated with repeated TLR.methodsResults