Anatomical predictors of high grade atrioventricular conduction disorders in patients with specific pacemaker implanted after TAVI

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. OnBehalf STIM TAVI-MS study Background The evolution of atrioventricular conduction disorders after transcatheter aortic valve implantation (TAVI) remains poorly understood. Recent studies have identified short membranous septum (MS) length, deep implantation depth (ID) or their relation as anatomic risk of high-grade AV block and permanent pacemaker implantation. Purpose : We sought to examine whether the atrioventricular (AV) membranous septum (MS) measured by computed tomography (CT) and the depth of valve implantation measured from the final aortic angiogram could predict high-grade atrioventricular block (HG AVB) after TAVI, based on specific pacemaker memory data. Methods STIM-TAVI-MS was a prospective, multicentre observational study that enrolled patients implanted with a specific dual chamber pacemaker after TAVI, with the SafeR algorithm activated, allowing continuous monitoring of atrioventricular conduction. The primary endpoint was the occurrence of late (after Day 7) high-grade atrioventricular block(s) during the year after TAVI. We measured on CT scans the coronal MS lenght, infra-annular MS lenght and the quantification of calcifications, on the final angiogram after TAVI we measured the implant depth (ID) to identifie ΔID-MS corresponding to the difference between implant depth and MS length. The variables were compared with the occurrence of late HG-AVB on PM memory data. Results : Among 82 patients, (mean age 84,5 years ± 4,8, self-expending valve n = 24, 29,3%), n = 47 (57.3%) had ≥1 late high-grade atrioventricular block. Mean coronal MS length was 8,1 ± 2,5 mm, mean infra annular MS was 3,4 ± 3.1 mm, mean calcification volume was 93.0 ± 88, 85,5± 104 and 141,5 ± 137,5 mm3 for the noncoronary, right coronary and left coronary cusp respectively. Mean implant depth was 7,3 ± 3,3mm, and mean ΔID-MS = -0,7 ± 4,1mm. There were no association between MS length (OR = 1,06; CI 0,91 to 1,24), ID (OR = 1,6; CI 0,85 to 2,9), nor ΔID-MS (OR = 0,67; CI 0,37 to 1,23) and late HG AVB. Calcification volume were not associated with late HG AVB. Conclusion In an high risk high grade AV block population after TAVI, anatomical analysis of MS length, degree of calcification, implant depth and ΔID-MS did not predict occurrence of late (> day 7 after TAVI ) high grade AV Blocks. Abstract Figure. CT scan A : aortic plane, B : MS lenght