Intraventricular Conduction Disturbances After Transcatheter Aortic Valve Implantation

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.

Prediction of conduction disturbances in patients undergoing transcatheter aortic valve replacement

AIM

Transcatheter aortic valve replacement (TAVR) can cause intraventricular conduction disturbances (ICA), particularly left bundle branch block (BBB) and high-degree atrioventricular block (HAVB). The aim of this study was to investigate clinical, anatomical, procedural, and electrophysiological parameters predicting ICA after TAVR.

METHODS

Patients with severe aortic stenosis (n = 203) without pacing devices undergoing TAVR with a self-expanding (n = 103) or balloon-expanding (n = 100) valve were enrolled. Clinical and anatomical parameters, such as length of the membranous septum (MS) and implantation depth, were assessed. His-ventricular interval (HVi) before and after implantation was determined. 12-lead-electrocardiograms (ECG) before, during and after 3 and 30 days after TAVR were analyzed for detection of any ICA.

RESULTS

Among 203 consecutive patients (aortic valve area 0.78 ± 0.18 cm², age 80 ± 6 years, 54% male, left ventricular ejection fraction 52 ± 10%), TAVR led to a significant prolongation of infranodal conduction in all patients from 49 ± 10 ms to 59 ± 16 ms (p = 0.01). The HVi prolongation was independent of valve types, occurrence of HAVB or ICA. Fifteen patients (7%) developed HAVB requiring permanent pacemaker (PPM) implantation and 63 patients (31%) developed ICA within 30 days. Pre-existing BBB (OR 11.64; 95% CI 2.87-47.20; p = 0.001), new-onset left BBB (OR 15.72; 95% CI 3.05-81.03; p = 0.001), and diabetes mellitus (OR 3.88; 95% CI 1.30-15.99; p = 0.02) independently predicted HAVB requiring PPM. Neither pre-existing right BBB, a prolonged postHVi, increases in PR duration, any of the TAVR implantation procedural and anatomic nor echocardiographic characteristics were predictive for later HAVB.

CONCLUSIONS

New-onset left BBB and diabetes mellitus independently predicted HAVB requiring PPM after TAVR and helped to identify patients at risk. Electrophysiologic study (EPS) of atrioventricular conduction was neither specific nor predictive of HAVB and can be skipped.

TRIAL REGISTRATION NUMBER

NCT04128384 ( https://www.

CLINICALTRIALS

gov ).

A 20-year journey in transcatheter aortic valve implantation: Evolution to current eminence

Since the first groundbreaking procedure in 2002, transcatheter aortic valve implantation (TAVI) has revolutionized the management of aortic stenosis (AS). Through striking developments in pertinent equipment and techniques, TAVI has now become the leading therapeutic strategy for aortic valve replacement in patients with severe symptomatic AS. The procedure streamlining from routine use of conscious sedation to a single arterial access approach, the newly adapted implantation techniques, and the introduction of novel technologies such as intravascular lithotripsy and the refinement of valve-bioprosthesis devices along with the accumulating experience have resulted in a dramatic reduction of complications and have improved associated outcomes that are now considered comparable or even superior to surgical aortic valve replacement (SAVR). These advances have opened the road to the use of TAVI in younger and lower-risk patients and up-to-date data from landmark studies have now established the outstanding efficacy and safety of TAVI in patients with low-surgical risk impelling the most recent ESC guidelines to propose TAVI, as the main therapeutic strategy for patients with AS aged 75 years or older. In this article, we aim to summarize the most recent advances and the current clinical aspects involving the use of TAVI, and we also attempt to highlight impending concerns that need to be further addressed.

Risk Stratification for Pacemaker Implantation after Transcatheter Aortic Valve Implantation in Patients with Right Bundle Branch Block

Background: Permanent pacemaker implantation (PPI) after transcatheter valve implantation (TAVI) is a common complication. Pre-existing right bundle branch block (RBBB) is a strong risk factor for PPI after TAVI. However, a patient-specific approach for risk stratification in this subgroup has not yet been established. Methods: We investigated TAVI patients with pre-existing RBBB to stratify risk factors for PPI and 1-year-mortality by detailed analysis of ECG data, RBBB morphology and degree of calcification in the implantation area assessed by computed tomography angiography. Results: Between 2010 and 2018, 2129 patients underwent TAVI at our institution. Among these, 98 pacemaker-naïve patients with pre-existing RBBB underwent a TAVI procedure. PPI, because of relevant conduction disturbances (CD), was necessary in 43 (43.9%) patients. PPI was more frequently indicated in women vs. men (62.1% vs. 32.8%, p = 0.004) and in men treated with a self-expandable vs. a balloon-expandable valve (58.3% vs. 26.5%, p = 0.035). ECG data (heart rhythm, PQ, QRS, QT) and RBBB morphology had no influence on PPI rate, whereas risk for PPI increased with the degree of calcification in the left septal His-/left bundle branch-area to a 9.375-fold odds for the 3rd tertile of calcification (1.639–53.621; p = 0.012). Overall, 1-year-mortality was comparable among patients with or without PPI (14.0% vs. 16.4%; p = 0.697). Conclusions: Patients with RBBB undergoing TAVI have a high risk of PPI. Among this subgroup, female patients, male patients treated with self-expandable valve types, patients with high load/degree of non-coronary LVOT calcification and patients with atrial fibrillation need enhanced surveillance for CD after procedure.

Impact of Valve Size on Paravalvular Leak and Valve Hemodynamics in Patients With Borderline Size Aortic Valve Annulus

Background

Transcatheter heart valve (THV) selection for transcatheter aortic valve implantation (TAVI) is crucial to achieve procedural success. Borderline aortic annulus size (BAAS), which allows a choice between two consecutive valve sizes, is a common challenge during device selection. In the present study, we evaluated TAVI outcomes in patients with BAAS according to THV size selection.

Methods

We performed a retrospective study including patients with severe aortic stenosis (AS) and BAAS, measured by multi-detector computed tomography (MDCT), undergoing TAVI with self-expandable (SE) or balloon-expandable (BE) THV from the Israeli multi-center TAVI registry. The aim was to evaluate outcomes of TAVI, mainly paravalvular leak (PVL) and valve hemodynamics, in patients with BAAS (based on MDCT) according to THV sizing selection in between 2 valve sizes. In addition, to investigate the benefit of shifting between different THV types (BE and SE) to avoid valve size selection in BAAS.

Results

Out of 2,352 patients with MDCT measurements, 598 patients with BAAS as defined for at least one THV type were included in the study. In BAAS patients treated with SE-THV, larger THV selection was associated with lower rate of PVL, compared to smaller THV (45.3 vs. 64.5%; pv = 0.0038). Regarding BE-THV, larger valve selection was associated with lower post-procedural transvalvular gradients compared to smaller THV (mean gradient: 9.9 ± 3.7 vs. 12.5 ± 7.2 mmHg; p = 0.019). Of note, rates of mortality, left bundle branch block, permanent pacemaker implantation, stroke, annular rupture, and/or coronary occlusion did not differ between groups.

Conclusion

BAAS is common among patients undergoing TAVI. Selection of a larger THV in these patients is associated with lower rates of PVL and optimized THV hemodynamics with no effect on procedural complications. Additionally, shift from borderline THV to non-borderline THV modified both THV hemodynamics and post-dilatation rates.

Non-invasive predictors for infranodal conduction delay in patients with left bundle branch block after TAVR

AIMS

Left bundle branch block (LBBB) is the most common conduction disorder after transcatheter aortic valve replacement (TAVR) with an increased risk of atrioventricular (AV) block. The aim of the current study was to identify non-invasive predictors for infranodal conduction delay in patients with LBBB.

METHODS

We analyzed consecutive patients undergoing TAVR with pre-existing or new-onset LBBB between August 2014 and August 2020. His ventricular (HV) interval measurement was performed on day 1 after TAVR. Baseline, procedural, as well as surface and intracardiac electrocardiographic parameters were included. Infranodal conduction delay was defined as HV interval > 55 ms.

RESULTS

Of 825 patients screened after TAVR, 151 patients (82 ± 6 years, 39% male) with LBBB were included. Among these, infranodal conduction delay was observed in 25%. ΔPR (difference in PR interval after and before TAVR), PR and QRS duration after TAVR were significantly longer in the group with HV prolongation. In a multivariate analysis in patients with sinus rhythm (n = 123), ΔPR (OR per 10 ms increase: 1.52; 95%CI: 1.19-2.01; p = 0.002) was the only independent factor associated with infranodal conduction delay. A change in PR interval by 20 ms yielded a specificity of 83% and a sensitivity of 46%, with a negative predictive value of 84% and a positive predictive value of 45% to predict HV prolongation.

CONCLUSIONS

Simple analysis of surface ECG and a calculated ΔPR < 20 ms can be used as predictor for the absence of infranodal conduction delay in post-TAVR patients with LBBB.

Device profile of the SAPIEN 3 transcatheter heart valve in low-risk patients with aortic stenosis: overview of its safety and efficacy

INTRODUCTION

Transcatheter aortic valve replacement (TAVR) has become a treatment of reference for patients with symptomatic severe aortic stenosis, and the balloon-expandable SAPIEN 3 and SAPIEN 3 Ultra transcatheter heart valve systems are two of the most broadly used worldwide. Lately, TAVR has progressively expanded toward the treatment of low-risk patients.

AREAS COVERED

In this review we aimed to describe the main characteristics of the SAPIEN 3 valve, and to delineate the main clinical findings regarding the safety and efficacy associated with this THV system in low-risk patients undergoing TAVR.

EXPERT OPINION

The approval of THV systems for use in low-risk patients has been a significant step forward in expanding current TAVR indications. Along with procedural refinement and growing operator experience, device iterations implemented in new-generation THV systems have played a vital role in the successful spread of TAVR. The availability of SAPIEN 3 represented an inflection point, as it allows for a predictable positioning and safer navigability while dramatically decreasing the rate of residual paravalvular leakage compared to previous balloon-expandable systems. However, some unresolved issues remain like the relatively high rates of conduction disturbances and the uncertainty about valve performance in the long-term. Future studies are warranted.

Advancements in Transcatheter Aortic Valve Implantation: A Focused Update

Transcatheter aortic valve implantation (TAVI) has become the leading technique for aortic valve replacement in symptomatic patients with severe aortic stenosis with conventional surgical aortic valve replacement (SAVR) now limited to patients younger than 65-75 years due to a combination of unsuitable anatomies (calcified raphae in bicuspid valves, coexistent aneurysm of the ascending aorta) and concerns on the absence of long-term data on TAVI durability. This incredible rise is linked to technological evolutions combined with increased operator experience, which led to procedural refinements and, accordingly, to better outcomes. The article describes the main and newest technical improvements, allowing an extension of the indications (valve-in-valve procedures, intravascular lithotripsy for severely calcified iliac vessels), and a reduction of complications (stroke, pacemaker implantation, aortic regurgitation).

Biomechanical Identification of High-Risk Patients Requiring Permanent Pacemaker After Transcatheter Aortic Valve Replacement

Background

Cardiac conduction disturbance requiring new permanent pacemaker implantation (PPI) is an important complication of TAVR that has been associated with increased mortality. It is extremely challenging to optimize the valve size alone to prevent a complete atrioventricular block (AVB).

Methods

In this study, we randomly took 48 patients who underwent TAVR and had been followed for at least 2 years to assess the risk of AVB. CT images of 48 patients with TAVR were analyzed using three-dimensional (3D) anatomical models of the aortic valve apparatus. The stresses were formulated according to loading force and tissue properties. Support vector regression (SVR) was used to model the relationship between AVB risk and biomechanical stresses. To avoid AVB, overlapping regions on the prosthetic valve where AV bundle passes will be removed as cylindrical sector with the angle θ. Thus, the optimization of the valve shape will be predicted with the joint optimization of the θ and valve size R.

Results

The average AVB risk prediction accuracy was 83.33% in the range from 0.8–0.85 with 95% CI for all cases; specifically, 85.71% for Group A (no AVB), and 80.0% for Group B (undergoing AVB after the TAVR).

Conclusions

This model can estimate the optimal valve size and shape to avoid the risk of AVB after TAVR. This optimization may eliminate the excessive stresses to keep the normal function of both AV bundle and valve leaflets, leading to a favorable clinical outcome. The combination of biomechanical properties and machine learning method substantially improved prediction of surgical results.

Recovery of conduction disorders after sutureless aortic valve replacement

OBJECTIVES

Conduction disorders and the need for permanent pacemaker (PPM) implantation after surgical aortic valve replacement are well-recognized complications. However, in the case of sutureless valve prostheses, it remains unknown whether pacemaker (PM) dependency and conduction disturbances resolve over time. Our aim was to evaluate whether conduction disorders after Perceval sutureless valve implantation recover during follow-up.

METHODS

Patients undergoing isolated surgical aortic valve replacement or concomitant aortic valve replacement with coronary artery bypass surgery using the Perceval sutureless valve, between January 2010 and July 2018, were included. Postoperative electrocardiogram findings were analysed to determine the incidence of new-onset left bundle branch blocks (LBBBs) and the requirement for PPM implantation. During a postoperative period of 6-18 months, electrocardiogram findings during PM checks were analysed to determine PM dependency and LBBB persistence.

RESULTS

Out of 184 patients who received a Perceval prosthesis during the study period, 39 (21.2%) patients developed new-onset LBBB and 10 patients (5.4%) received a PPM postoperatively. The occurrence of conduction disorders was not associated with valve size. Follow-up was completed in 176 (95.7%) patients. In patients with a new-onset LBBB, 35.9% recovered during follow-up (P = 0.001). Seven out of 10 (70%) patients remained PM dependent.

CONCLUSIONS

After Perceval aortic valve implantation, new-onset LBBB recovers in more than one-third of patients during follow-up. In patients who needed a postoperative PPM, the majority remained PM dependent.