Temporal Incidence and Predictors of High-Grade Atrioventricular Block After Transcatheter Aortic Valve Replacement

High-Degree Atrioventricular Block and Torsades De Pointes in Severe Aortic Stenosis Treated With Transcatheter Aortic Valve Replacement

Severe aortic stenosis (AS) significantly elevates cardiovascular risk, predisposing patients to high-degree atrioventricular (AV) block and life-threatening tachyarrhythmias, including torsades de pointes (TdP). This case report presents a patient with severe AS who developed high-degree AV block and, subsequently, TdP, highlighting the interplay between bradycardia and mechanisms that trigger ventricular tachycardias. The case underscores the importance of identifying and managing these risk factors to improve patient outcomes.

Left ventricular mechanical dispersion as a predictor of the need for pacemaker implantation after transcatheter aortic valve implantation: MeDiPace TAVI study

AIMS

Permanent pacemaker (PM) implantation is common after transcatheter aortic valve implantation (TAVI). Left ventricular mechanical dispersion (MeDi) by speckle tracking echocardiography is a marker of fibrosis that causes alterations in the conduction system. We hypothesized that MeDi can be a predictor of the need for PM implantation after TAVI.

METHODS AND RESULTS

Consecutively, 200 TAVI patients were enrolled. Transthoracic echocardiography and electrocardiography examinations were recorded before TAVI to evaluate global longitudinal strain (GLS), MeDi, and conduction disturbances. PM implantation information was obtained 3 months after TAVI. Patients were stratified into PM or no PM group. Mean age was 80 + 7 years (44% women). Twenty-nine patients (16%) received PM. MeDi, QRS duration, existence of right bundle branch abnormality (RBBB), and first-degree atrioventricular (AV) block were significantly different between groups. MeDi was 57 ± 15 ms and 48 ± 12 ms in PM and no PM groups, respectively (P < 0.001). In multivariate analysis, MeDi predicted the need for PM after TAVI independently of GLS, QRS duration, RBBB, and first-degree AV block [odds ratio (OR): 1.73, 95% confidence interval (CI): 1.22-2.45] with an area under the curve (AUC) of 0.68 in receiver operating characteristic (ROC) curves. Moreover, RBBB was an independent predictor of PM need after TAVI (OR: 8.98, 95% CI: 1.78-45.03). When added to RBBB, MeDi had an incremental predictive value with an AUC of 0.73 in ROC curves (P = 0.01).

CONCLUSION

MeDi may be used as an echocardiographic functional predictor of the need for PM after TAVI.

[Calcification distributional density of the aortic-valvular complex is an independent risk factor for conduction block following self-expanding transcatheter aortic valve replacement]

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.

Utility of rapid atrial pacing before and after TAVR with balloon-expandable valve in predicting permanent pacemaker implantation

BACKGROUND

High-grade or complete atrioventricular block (AVB) requiring permanent pacemaker (PPM) implantation is a known complication of transcatheter aortic valve replacement (TAVR). Wenckebach AVB induced by rapid atrial pacing (RAP) after TAVR was previously demonstrated in an observational analysis to be an independent predictor for PPM. We sought to investigate the utility of both pre- and post-TAVR RAP in predicting PPM implantation.

METHODS

In a single-center, prospective study, 421 patients underwent TAVR with balloon-expandable valves (BEV) between April 2020 and August 2021. Intraprocedural RAP was performed in patients without a pre-existing pacemaker, atrial fibrillation/flutter, or intraprocedural complete AVB to assess for RAP-induced Wenckebach AVB. The primary outcome was PPM within 30 days after TAVR.

RESULTS

RAP was performed in 253 patients, of whom 91.3% underwent post-TAVR RAP and 61.2% underwent pre-TAVR RAP. The overall PPM implantation rate at 30 days was 9.9%. Although there was a numerically higher rate of PPM at 30 days in patients with RAP-induced Wenckebach AVB, it did not reach statistical significance (13.3% vs. 8.4%, p = 0.23). In a multivariable analysis, RAP-induced Wenckebach was not an independent predictor for PPM implantation at 30 days after TAVR. PPM rates at 30 days were comparable in patients with or without pre-TAVR pacing-induced Wenckebach AVB (11.8% vs. 8.2%, p = 0.51) and post-TAVR pacing-induced Wenckebach AVB (10.2% vs. 5.8%, p = 0.25).

CONCLUSION

In patients who underwent TAVR with BEV, there were no statistically significant differences in PPM implantation rates at 30 days regardless of the presence or absence of RAP-induced Wenckebach AVB. Due to conflicting results between the present study and the prior observational analysis, future studies with larger sample sizes are warranted to determine the role of RAP during TAVR as a risk-stratification tool for significant AVB requiring PPM after TAVR.

Risk Factors, Management, and Avoidance of Conduction System Disease after Transcatheter Aortic Valve Replacement

Transcatheter valve replacement (TAVR) is a rapidly developing modality to treat patients with aortic stenosis (AS). Conduction disease post TAVR is one of the most frequent and serious complications experienced by patients. Multiple factors contribute to the risk of conduction disease, including AS and the severity of valve calcification, patients' pre-existing conditions (i.e., conduction disease, anatomical variations, and short septum) in addition to procedure-related factors (e.g., self-expanding valves, implantation depth, valve-to-annulus ratio, and procedure technique). Detailed evaluation of risk profiles could allow us to better prevent, recognize, and treat this entity. Available evidence on management of conduction disease post TAVR is based on expert opinion and varies widely. Currently, conduction disease in TAVR patients is managed depending on patient risk, with minimal-to-no inpatient/outpatient observation, inpatient monitoring (24-48 h) followed by ambulatory monitoring, or either prolonged inpatient and outpatient monitoring or permanent pacemaker implantation. Herein, we review the incidence and risk factors of TAVR-associated conduction disease and discuss its management.

Transcatheter Aortic Valve Implantation: Addressing the Subsequent Risk of Permanent Pacemaker Implantation

Transcatheter aortic valve implantation (TAVI) is now a commonly used therapy in patients with severe aortic stenosis, even in those patients at low surgical risk. The indications for TAVI have broadened as the therapy has proven to be safe and effective. Most challenges associated with TAVI after its initial introduction have been impressively reduced; however, the possible need for post-TAVI permanent pacemaker implantation (PPI) secondary to conduction disturbances continues to be on the radar. Conduction abnormalities post-TAVI are always of concern given that the aortic valve lies in close proximity to critical components of the cardiac conduction system. This review will present a summary of noteworthy pre-and post-procedural conduction blocks, the best use of telemetry and ambulatory device monitoring to avoid unnecessary PPI or to recognize the need for late PPI due to delayed high-grade conduction blocks, predictors to identify those patients at greatest risk of requiring PPI, important CT measurements and considerations to optimize TAVI planning, and the utility of the MInimizing Depth According to the membranous Septum (MIDAS) technique and the cusp-overlap technique. It is stressed that careful membranous septal (MS) length measurement by MDCT during pre-TAVI planning is necessary to establish the optimal implantation depth before the procedure to reduce the risk of compression of the MS and consequent damage to the cardiac conduction system.

Invasive electrophysiological testing to predict and guide permanent pacemaker implantation after transcatheter aortic valve implantation: A meta-analysis

Background

Atrioventricular conduction abnormalities after transcatheter aortic valve implantation (TAVI) are common. The value of electrophysiological study (EPS) for risk stratification of high-grade atrioventricular block (HG-AVB) and guidance of permanent pacemaker (PPM) implantation is poorly defined.

Objective

The purpose of this study was to identify EPS parameters associated with HG-AVB and determine the value of EPS-guided PPM implantation after TAVI.

Methods

We performed a systematic review and meta-analysis of studies investigating the value of EPS parameters for risk stratification of TAVI-related HG-AVB and for guidance of PPM implantation among patients with equivocal PPM indications after TAVI.

Results

Eighteen studies (1230 patients) were eligible. In 7 studies, EPS was performed only after TAVI, whereas in 11 studies EPS was performed both before and after TAVI. Overall PPM implantation rate for HG-AVB was 16%. AV conduction intervals prolonged after TAVI, with the AH and HV intervals showing the largest magnitude of changes. Pre-TAVI HV >70 ms and the absolute value of the post-TAVI HV interval were associated with subsequent HG-AVB and PPM implantation with odds ratios of 2.53 (95% confidence interval [CI] 1.11-5.81; P = .04) and 1.10 (95% CI 1.03-1.17; P = .02; per 1-ms increase), respectively. In 10 studies, PPM was also implanted due to abnormal EPS findings in patients with equivocal PPM indications post-TAVI (typically new left bundle branch block or transient HG-AVB). Among them, the rate of long-term PPM dependency was 57%.

Conclusion

Selective EPS testing may assist in the risk stratification of post-TAVI HG-AVB and in the guidance of PPM implantation, especially in patients with equivocal PPM indications post-TAVI.

The Technological Basis of a Balloon-Expandable TAVR System: Non-occlusive Deployment, Anchorage in the Absence of Calcification and Polymer Leaflets

Leaflet durability and costs restrict contemporary trans-catheter aortic valve replacement (TAVR) largely to elderly patients in affluent countries. TAVR that are easily deployable, avoid secondary procedures and are also suitable for younger patients and non-calcific aortic regurgitation (AR) would significantly expand their global reach. Recognizing the reduced need for post-implantation pacemakers in balloon-expandable (BE) TAVR and the recent advances with potentially superior leaflet materials, a trans-catheter BE-system was developed that allows tactile, non-occlusive deployment without rapid pacing, direct attachment of both bioprosthetic and polymer leaflets onto a shape-stabilized scallop and anchorage achieved by plastic deformation even in the absence of calcification. Three sizes were developed from nickel-cobalt-chromium MP35N alloy tubes: Small/23 mm, Medium/26 mm and Large/29 mm. Crimp-diameters of valves with both bioprosthetic (sandwich-crosslinked decellularized pericardium) and polymer leaflets (triblock polyurethane combining siloxane and carbonate segments) match those of modern clinically used BE TAVR. Balloon expansion favors the wing-structures of the stent thereby creating supra-annular anchors whose diameter exceeds the outer diameter at the waist level by a quarter. In the pulse duplicator, polymer and bioprosthetic TAVR showed equivalent fluid dynamics with excellent EOA, pressure gradients and regurgitation volumes. Post-deployment fatigue resistance surpassed ISO requirements. The radial force of the helical deployment balloon at different filling pressures resulted in a fully developed anchorage profile of the valves from two thirds of their maximum deployment diameter onwards. By combining a unique balloon-expandable TAVR system that also caters for non-calcific AR with polymer leaflets, a powerful, potentially disruptive technology for heart valve disease has been incorporated into a TAVR that addresses global needs. While fulfilling key prerequisites for expanding the scope of TAVR to the vast number of patients of low- to middle income countries living with rheumatic heart disease the system may eventually also bring hope to patients of high-income countries presently excluded from TAVR for being too young.

Temporal Incidence and Predictors of High-Grade Atrioventricular Block After Transcatheter Aortic Valve Replacement

Background

The temporal incidence of high‐grade atrioventricular block (HAVB) after transcatheter aortic valve replacement (TAVR) is uncertain. As a result, periprocedural monitoring and pacing strategies remain controversial. This study aimed to describe the temporal incidence of initial episode of HAVB stratified by pre‐ and post‐TAVR conduction and identify predictors of delayed events.

Methods and Results

Consecutive patients undergoing TAVR at a single center between February 2012 and June 2019 were retrospectively assessed for HAVB within 30 days. Patients with prior aortic valve replacement, permanent pacemaker (PPM), or conversion to surgical replacement were excluded. Multivariable logistic regression was performed to assess predictors of delayed HAVB (initial event >24 hours post‐TAVR). A total of 953 patients were included in this study. HAVB occurred in 153 (16.1%). After exclusion of those with prophylactic PPM placed post‐TAVR, the incidence of delayed HAVB was 33/882 (3.7%). Variables independently associated with delayed HAVB included baseline first‐degree atrioventricular block or right bundle‐branch block, self‐expanding valve, and new left bundle‐branch block. Forty patients had intraprocedural transient HAVB, including 16 who developed HAVB recurrence and 6 who had PPM implantation without recurrence. PPM was placed for HAVB in 130 (13.6%) (self‐expanding valve, 23.7% versus balloon‐expandable valve, 11.9%; P<0.001). Eight (0.8%) patients died by 30 days, including 1 unexplained without PPM present.

Conclusions

Delayed HAVB occurs with higher frequency in patients with baseline first‐degree atrioventricular block or right bundle‐branch block, new left bundle‐branch block, and self‐expanding valve. These findings provide insight into optimal monitoring and pacing strategies based on periprocedural ECG findings.