Abstract: Objective To evaluate the effect of calcification distributional density in different regions of aortic-valvular complex (AVC) on postoperative new-onset conduction block (CB) following transcatheter aortic valve replacement (TAVR) using self-expandable valves (SEV) made in China. Methods From January, 2016 to December, 2022, 73 patients with severe aortic valve stenosis received Venus-A prosthetic valve replacement using SEV made in China, and postoperative new-onset CB occurred in 18 (24.7% ) of the patients. The baseline data, imaging and intervention- related data were compared were between the patients with CB and those without CB. Univariate and multivariate logistic regression analysis was used for investigating the independent risk factors for new- onset CB after TAVR, and the predictive performance of these risk factors was evaluated using receiver operating characteristic (ROC) curve and DeLong test. Results Compared with those with CB, the patients experiencing postoperative new-onset CB had a greater implantation depth (6.77±2.45 mm vs 5.11±3.28 mm, P=0.027), a smaller difference between the membranous septum length and the implantation depth (MSID) (0.68±3.49 mm vs 2.82±3.88 mm, P=0.036), and a higher calcification distributional density of the left coronary sinus (LCS) in the device landing zone (DLZ) (P=0.026). Multivariate logistic analysis revealed that DLZ-LCS calcification distributional density and MSID were independent risk (protective) factors for new-onset CB following TAVR. ROC curve analysis showed that the AUC of MSID and DLZ-LCS calcification distributional density was 0.775 and 0.716, respectively, and their combination had had a significantly higher AUC of 0.890 (P=0.041 and 0.027, respectively). Conclusion The DLZ-LCS calcification distributional density is an independent risk factor for new-onset CB following TAVR using SEV. The conduction complications following TAVR can be effectively predicted using this calcification indicator combined with MSID.

Key words: aortic valve disease; transcatheter aortic valve replacement; conduction block; computed tomography; annulus size