Use of Electrophysiological Studies in Transcatheter Aortic Valve Implantation

Conduction dynamics over time after transcatheter aortic valve replacement: An expert review

New conduction disorders remain a frequent complication in current transcatheter aortic valve replacement (TAVR) era. Left bundle branch block (LBBB) occurs early in about 20-30 % of TAVR-patients, persists at 1 month in about 35-45 % of cases and will likely remain thereafter. Third-degree atrioventricular block (AV3B) affects approximately 15 % of patients. Pacemaker dependency gradually decreases throughout follow-up and approximately 25-35 % of patients remain pacemaker dependent at one year. We aimed to review what is currently known about the dynamics of acquired conduction disorders, including extraction of predictors, and how to interpret these dynamics in light of an early discharge policy.

The utility and impact of outpatient telemetry monitoring in post-transcatheter aortic valve replacement patients

BACKGROUND

Conduction disturbances are a common complication of transcatheter aortic valve replacement (TAVR). Mobile Cardiac Telemetry (MCT) allows for continuous monitoring with near "real time" alerts and has allowed for timely detection of conduction abnormalities and pacemaker placement in small trials. A standardized, systematic approach utilizing MCT devices post TAVR has not been widely implemented, leading to variation in use across hospital systems.

OBJECTIVES

Our aim was to evaluate the utility of a standardized, systematic approach utilizing routine MCT to facilitate safe and earlier discharge by identifying conduction disturbances requiring permanent pacemaker (PPM) placement. We also sought to assess the occurrence of actionable arrhythmias in post-TAVR patients.

METHODS

Using guidance from the JACC Scientific Expert Panel, a protocol was implemented starting in December 2019 to guide PPM placement post-TAVR across our health system. All patients who underwent TAVR from December 2019 to June 2021 across four hospitals within Northwell Health, who did not receive or have a pre-existing PPM received an MCT device at discharge and were monitored for 30 days. Clinical and follow-up data were collected and compared to pre initiative patients.

RESULTS

During the initiative 693 patients were monitored with MCT upon discharge, 21 of whom required PPM placement. Eight of these patients had no conduction abnormality on initial or discharge ECG. 59 (8.6 %) patients were found to have new atrial fibrillation or flutter via MCT monitoring. There were no adverse events in the initiative group. Prior to the initiative, 1281 patients underwent TAVR over a one-year period. The initiative group had significantly shorter length of stay than pre-initiative patients (2.5 ± 4.5 vs 3.0 ± 3.8 days, p < 0.001) and lower overall PPM placement rate within 30 days post-TAVR (16 % vs 20.5 %, P = 0.0125).

CONCLUSIONS

In our study, implementation of a standardized, systematic approach utilizing MCT in post-TAVR patients was safe and allowed for timely detection of conduction abnormalities requiring pacemaker placement. This strategy also detected new atrial fibrillation and flutter. Reduction in post TAVR pacemaker rate and length of stay were also noted although this effect is multifactorial.

Transcatheter Aortic Valve Replacement in Elderly Patients: Opportunities and Challenges

Over the past two decades, the rapid evolution of transcatheter aortic valve replacement (TAVR) has revolutionized the management of severe aortic stenosis (AS) in the elderly. The prevalence of comorbidities in elderly AS patients presents a considerable challenge to the effectiveness and prognosis of patients after TAVR. In this article, we aim to summarize some of the clinical aspects of the current use of TAVR in elderly patients and attempt to highlight the challenges and issues that need further consideration.

Yield of the electrophysiological study in patients with new-onset left bundle branch block after transcathether aortic valve replacement: The PR interval matters

Background

Studies suggest that performing an electrophysiological study (EPS) may be useful to identify patients with new-onset left bundle branch block (LBBB) post-TAVR at risk of atrioventricular block. However, tools to optimize the yield of such strategy are needed. We therefore aimed to investigate whether 12-lead ECG changes post-TAVR may help identify patients with abnormal EPS findings.

Materials and methods

Consecutive patients with new-onset LBBB post-TAVR who underwent EPS were included. PR and QRS intervals were measured on 12-lead ECG pre-TAVR and during EPS. Abnormal EPS was defined as an HV interval > 55 ms.

Results

Among 61 patients, 28 (46%) had an HV interval > 55 ms after TAVR. Post-TAVR PR interval and ΔPR (PR-post-pre-TAVR) were significantly longer in patients with prolonged HV (PR: 188 ± 38 vs. 228 ± 34 ms, p < 0.001, ΔPR: 10 ± 30 vs. 34 ± 23 ms, p = 0.001), while no difference was found in QRS duration. PR and ΔPR intervals both effectively discriminated patients with HV > 55 ms (AUC = 0.804 and 0.769, respectively; p < 0.001). A PR > 200 ms identified patients with abnormal EPS results with a sensitivity of 89% and a negative predictive value (NPV) of 88%. ΔPR ≥ 20 ms alone provided a somewhat lower sensitivity (64%) but combining both criteria (i.e., PR > 200 ms or ΔPR ≥ 20 ms) identified almost every patients with abnormal HV (sensitivity = 96%, NPV = 95%). Selecting EPS candidate based on both criteria would avoid 1/3 of exams.

Conclusion

PR interval assessment may be useful to select patients with new-onset LBBB after TAVR who may benefit most from an EPS. In patients with PR ≤ 200 ms and ΔPR < 20 ms the likelihood of abnormal EPS is very low independently of QRS changes.

Dependence on permanent pacemakers inserted after transcatheter aortic valve implantation: predictive factors in a ten-year retrospective analysis: Rates and predictors of pacemaker dependence after TAVI

AIMS

The requirement for a permanent pacemaker (PPM) is an important sequela after transcatheter aortic valve implantation (TAVI). The aim of this analysis was to identify predictive factors for pacemaker dependence in PPM-insertions post-TAVI.

METHODS AND RESULTS

A retrospective analysis of all PPM insertions done between January 2009 and December 2018 (n=1,373) identified 33 patients who received a PPM within one month of TAVI. Thirty-two had completed a PPM check at one year and were included in the final analyses. Of those who had PPM insertions after TAVI, 41% (13/32) were not PPM-dependent at one year. This cohort was predominantly European (94%) and over half were octogenerians (56%). Statistically significant associations with being PPM-dependent at one year include intraoperative PPM dependence (OR 5.714 [95% CI: 1.163-28.070]; p=0.032), third-degree heart block being the indication for PPM insertion (OR 8.533 [95% CI: 1.616-45.063]; p=0.012) and mean valve depth over 6.0 mm (OR 6.222 [95% CI: 1.200-32.273]; p=0.030).

CONCLUSIONS

A significant number of patients are not dependent on the PPMs inserted after TAVI. Although small, our study suggests that those who are pacing-dependent intraoperatively, have a third-degree heart block as their PPM indication or have a mean valve depth of over 6.0 mm, are more likely to be pacing-dependent in the long term. Larger studies are required to draw more definitive conclusions.

Anatomical characteristics of the membranous septum are predictive of pacemaker requirement in patients undergoing transcatheter aortic valve replacement

PURPOSE

We aimed to study the characteristics of the membranous septum (MS) and its relationship with the aortic valve (AoV) and aortic annulus (AA) in patients who required PPM post-TAVR.

METHODS

We performed a retrospective case-control study of 144 patients undergoing TAVR from 2016 to 2018. Thirty-four patients, requiring PPM implantation, were compared with 34 matched controls who did not require pacing. The total MS length, supra-annular MS (SA-MS) length, infra-annular MS (IA-MS) length, angle between the plane of the AA and MS (AA-MS), and degree of AoV calcifications (AVC) were obtained from preoperative CT. AoV prosthesis implantation depth was obtained from intra-operative fluoroscopy.

RESULTS

There were no significant differences in valve type (self-expandable: 23 cases vs 25 controls, and balloon-expandable: 11 vs 9, p = 0.79), degree of AVC (0.65 cm³ vs 0.82 cm³, p = 0.62), or implantation depth (7.76 mm vs 7.28 mm, p = 0.83). Compared to controls, there was no difference in total MS length (6.68 mm vs 6.06 mm, p = 0.97), but the IA-MS was significantly shorter (3.64 mm vs 4.56 mm, p = 0.02) and the SA-MS was significantly longer (2.73 mm vs 1.67 mm, p = 0.02) in patients requiring PPM. Patients requiring PPM also had a larger AA-MS angle (103.5° vs 96.7°, p = 0.01).

CONCLUSION

The position of the MS with respect to the AA and MS distance below the annular plane were more closely associated with post-TAVR conduction abnormalities requiring PPM than the absolute length of the MS. Patients undergoing TAVR with such anatomy have a higher risk of requiring PPM and should be monitored for developing these complications.

Incidence, Predictors, and Implications of Permanent Pacemaker Requirement After Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) is a safe and feasible alternative to surgery in patients with symptomatic severe aortic stenosis regardless of the surgical risk. Conduction abnormalities requiring permanent pacemaker (PPM) implantation remain a common finding after TAVR due to the close proximity of the atrioventricular conduction system to the aortic root. High-grade atrioventricular block and new onset left bundle branch block (LBBB) are the most commonly reported conduction abnormalities after TAVR. The overall rate of PPM implantation after TAVR varies and is related to pre-procedural and intraprocedural factors. The available literature regarding the impact of conduction abnormalities and PPM requirement on morbidity and mortality is still conflicting. Pre-procedural conduction abnormalities such as right bundle branch block and LBBB have been linked with increased PPM implantation and mortality after TAVR. When screening patients for TAVR, heart teams should be aware of various anatomical and pathophysiological conditions that make patients more susceptible to increased risk of conduction abnormalities and PPM requirement after the procedure. This is particularly important as TAVR has been recently approved for patients with low surgical risk. The purpose of this review is to discuss the incidence, predictors, impact, and management of the various conduction abnormalities requiring PPM implantation in patients undergoing TAVR.

Electrophysiological Study-Guided Permanent Pacemaker Implantation in Patients With Conduction Disturbances Following Transcatheter Aortic Valve Implantation

Conduction disturbances remain common following transcatheter aortic valve implantation (TAVI). Aside from high-degree atrioventricular block (HAVB), their optimal management remains elusive. Invasive electrophysiological studies (EPS) may help stratify patients at low or high risk of HAVB allowing for an early discharge or permanent pacemaker (PPM) implantation among patients with conduction disturbances. We evaluated the safety and diagnostic performances of an EPS-guided PPM implantation strategy among TAVI recipients with conduction disturbances not representing absolute indications for PPM. All patients who underwent TAVI at a single expert center from June 2017 to July 2020 who underwent an EPS during the index hospitalization were included in the present study. False negative outcomes were defined as patients discharged without PPM implantation who required PPM for HAVB within 6 months of the initial EPS. False positive outcomes were defined as patients discharged with a PPM with a ventricular pacing percentage <1% at follow-up. A total of 78 patients were included (median age 83.5, 39% female), among whom 35 patients (45%) received a PPM following EPS. The sensitivity, specificity, positive and negative predictive values of the EPS-guided PPM implantation strategy were 100%, 89.6%, 81.5%, and 100%, respectively. Six patients suffered a mechanical HAVB during EPS and received a PPM. These 6 patients showed PPM dependency at follow-up. In conclusion, an EPS-guided PPM implantation strategy for managing post-TAVI conduction disturbances appears effective to identify patients who can be safely discharged without PPM implantation.