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

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

Predicting pacemaker implantation after TAVR with procedural CT

Background and aim The need for permanent pacemaker implantation (PPMI) is a burdensome complication of transcatheter aortic valve replacement (TAVR). Calcium distribution in the aortic-valvular complex (AVC) and, more recently, membranous septum (MS) length seem to be surrogate markers for conduction abnormalities after specific last generation balloon and self-expandable expandable valves. We sough to evaluate whether such pre-procedural association remains across the entire device spectrum. Methods Single-centre prospective study of 239 consecutive patients (140 women, median age of 84) with severe symptomatic aortic stenosis patients who underwent ECG-gated contrast-enhanced multi-detector computed tomography (MSCT) before TAVR since Jun/2017. Exclusion criteria were those with previous PPMI, previous bioprothesis, congenital bicuspid valve, and poor imaging quality. The J-score with an 850-Hounsfield unit threshold was used to detect areas of calcium in the region of interest. AVC was characterized by leaflet sector and region, using 3mensio Valves software 7.0 TM. An independent team retrospectively measured MS length blindly by determining the thinnest part of the interventricular septum in the coronal view in the better-defined systolic phase (usually at 40% of the R-R interval, Figure). Device selection (75.8% self-expandable devices, 20.1% balloon expandable, 3.1% other) and positioning were performed according to the operator criteria. Final implant depth was assessed based on the pre-release angiogram or final aortography. Results Mortality at 30-days was 1.3% and PPMI occurred in 43 patients (18%). Median MS length was 9.59mm (IQR: 3.11mm). After multivariable logistic regression analysis, MS length emerged as the single significant protective predictor for PPMI (OR: 0.14; 95% 95% CI: 0.05–0.42; p<0.001), independently of the device used (p<0.001). MS length showed strong discriminatory ability for PPMI (c-statistic 0.93; 95% CI 0.88–0.99). Sensitivity/specificity decision plots yielded an MS length of 6.9 mm as the optimal cut-off point for predicting the need for PPMI with a positive and negative predictive value of 91% and 93%, respectively (Figure). There wasn't any calcium accumulation within a specific region of AVC that independently predicted the outcome. Conclusion In our experience, a short membranous septum was strongly and independently associated with new permanent pacemaker implantation, regardless of the device type. Our findings suggest that this simple measure should be routinely made to help device selection and implantation technique. Funding Acknowledgement Type of funding source: None

Computed tomography derived predictors of permanent pacemaker implantation after transcatheter aortic valve implantation: a meta-analysis

Background Transcatheter aortic valve implantation (TAVI) is a well-established alternative to surgery for the treatment of patients with severe symptomatic aortic stenosis at high and intermediate surgical risk. Unfortunately, the occurrence of electrical conduction disturbances remains one of the most frequent complications of the procedure. While the impact of electrocardiographic and procedural predictors on PPI is well examined, there is still a lack of knowledge regarding anatomical predictors screened by multislice computed tomography (MSCT). Purpose We performed a meta-analysis to summarize available studies that reported the incidence of PPI after TAVI with new-generation devices and provided raw data for preprocedural MSCT. Methods The authors conducted a literature search in PubMed database until December 31, 2019 to identify studies that investigated preprocedural MSCT data and rate of PPI following TAVI with new-generation devices. Twelve observational studies (n=3133) met inclusion criteria for final analysis. Results PPI was performed in 509 patients (16.2%) after TAVI, mostly due to high degree atrioventricular (AV) block (80.8%). The rate of PPI varied widely from 7.9% to 35.8% in individual studies. Regarding secondary endpoints' analysis of relative risk (RR) and mean difference (MD) electrocardiographic PPI-predictors after TAVI appeared to be pre-existing atrial fibrillation (AF) (RR 1.21; 95% CI 1.05–1.40; p=0.008), right bundle branch block (RBBB) (RR 4.22; 95% CI 3.30–5.41; p<0.0001) and AV block grade I (RR 1.63; 95% CI 1.16–2.29; p=0.005). Patients requiring PPI had larger annulus perimeter (MD 1.66 mm; 95% CI 0.67–2.66 mm; p=0.001) and shorter membranous septum length (MD −0.86 mm; 95% CI −1.74–0.02 mm; p=0.05) assessed by preprocedural MSCT. Concerning calcium load of device landing zone, pacemaker dependent patients showed increased calcification of the non-coronary cusp (MD 39.76 mm3; 95% CI 18.60–60.93 mm3; p=0.0002), the left-coronary cusp (LCC) (MD 47.60 mm3; 95% CI 19.40–75.81 mm3; p=0.0009) and the total left ventricular outflow tract (LVOT) (MD 19.17 mm3; 95% CI 6.68–31.66 mm3; p=0.003). Lower implantation depth (MD 0.83 mm from NCC; 95% CI 0.20–1.47 mm; p=0.01) and oversizing by annulus diameter/area (MD 1.76%; 95% CI 0.68–2.84%; p=0.001) were procedural predictors of PPI following TAVI. Conclusion This structured meta-analysis proved PPI rate in 16.2% of patients following TAVI. Beside well-known electrocardiographic (AF, RBBB, AV block grade I) and procedural predictors (implantation depth, oversizing) this meta-analysis showed for the first time that MSCT derived anatomical values (annulus perimeter, membranous septum length) and distribution of device landing zone's calcification (NCC, LCC, LVOT) are associated with increased risk of PPI following TAVI. Funding Acknowledgement Type of funding source: None

Impact of tapered-shaped left ventricular outflow tract on permanent pacemaker implantation after the third-generation balloon-expandable valve implantation

Background In the era of transcatheter aortic valve implantation (TAVI) for patients with lower surgical risk, conduction disturbances requiring permanent pacemaker implantation (PPI) after TAVI remain a serious concern. The association between tapered-shaped left ventricular outflow tract (LVOT) and PPI after TAVI has not been elucidated. Purposes This study sought to identify predictors for PPI after TAVI with the third-generation balloon-expandable valve, with focus on LVOT morphology. Methods Of 272 consecutive patients treated with the third-generation balloon-expandable valve, 256 patients without previous PPI or bicuspid valve were retrospectively analyzed. Results PPI was implanted after TAVI in 20 (7.8%) patients. Patients requiring PPI had smaller LVOT area (356.3 mm2 vs. 399.4 mm2, p=0.011). Moreover, receiver-operating characteristic (ROC) statistics showed that LVOT area /annulus area possessed significantly higher predictive ability than LVOT area (area under the curve: 0.91 [95% confidence interval [CI]: 0.84 to 0.95] vs. 0.67 [95% CI: 0.57 to 0.77], p<0.001). Multivariable analysis revealed LVOT area /annulus area (odds ratio [OR]: 1.93 [95% CI: 1.38–2.71]; p<0.001 per % of decreasing), the difference between membranous septum length and implantation depth (ΔMSID) (OR: 6.82 [95% CI 2.39–19.48]; p<0.001 per mm of decreasing) and pre-existing complete right bundle branch block (CRBBB) (OR: 32.38 [95% CI 2.30–455.63]; p=0.002) as independent predictors of PPI. Further analysis using ROC statistics revealed LVOT area / annulus area of 88.5% and ΔMSID of 1.8 mm as the optimal cutoff points for prediction of PPI after the third-generation balloon-expandable valve implantation, with high negative predictive values of 98.1% and 99.0%, respectively. Figure shows the PPI rates stratified by the number of following predictors: LVOT area /annulus area <88.5%, ΔMSID <1.8 mm and pre-existing CRBBB. Patients with 2 or more predictors had significantly higher PPI rates than those with 1 or less predictor (67% [18 of 27 patients] vs. 1% [2 of 229 patients], p<0.001). Conclusions LVOT area /annulus area, ΔMSID and pre-existing CRBBB were identified as powerful independent predictors for PPI after TAVI. Higher valve implantation is important to prevent excessive PPI especially for patients with pre-procedural tapered-shaped LVOT, short membranous septum or pre-existing CRBBB. PPI rates stratified by predictors Funding Acknowledgement Type of funding source: None