Transcatheter aortic valve implantation-induced left bundle branch block: causes and consequences

Impact of New-Onset Conduction Disturbances following Transcatheter Aortic Valve Replacement on Outcomes: A Single-Center Study

Background

Transcatheter aortic valve replacement (TAVR) is known to increase the incidence of conduction disturbances compared to surgical aortic valve replacement; however, there are limited data on the impact and duration of these conduction disturbances on longer term outcomes.

Objective

To determine the differential impact of persistent versus nonpersistent new-onset conduction disturbances on TAVR-related complications and outcomes.

Methods

This is a single-center retrospective analysis of 927 consecutive patients with aortic stenosis who underwent TAVR at Yale New Haven Hospital from July 2012 to August 2019. Patients with new-onset conduction disturbances within 7 days following TAVR were selected for this study. Persistent and nonpersistent disturbances were, respectively, defined as persisting or not persisting on all patient ECGs for up to 1.5 years after TAVR or until death.

Results

Within 7 days after TAVR, conduction disturbances occurred in 42.3% (392/927) of the patients. Conduction disturbances persisted in 150 (38%) patients and did not persist in 187 (48%) patients, and 55 (14%) patients were excluded for having mixed (both persistent and nonpersistent) disturbances. Compared with nonpersistent disturbances, patients with persistent disturbances were more likely to receive a PPM within 7 days after the TAVR procedure (46.0% versus 4.3%, p < 0.001) and had a greater unadjusted 1-year cardiac-related and all-cause mortality risk (HR 2.54, p=0.044 and HR 1.90, p=0.046, respectively).

Conclusion

Persistent conduction disturbances were associated with a greater cardiac and all-cause mortality rate at one year following TAVR. Future research should investigate periprocedural factors to reduce persistent conduction disturbances and outcomes beyond one year follow-up.

Occurrence and Persistency of Conduction Disturbances during Transcatheter Aortic Valve Implantation

Background and Objectives: Conduction disturbances such as left bundle branch block (LBBB) and complete atrio-ventricular block (cAVB) are relatively frequent complications following trans-catheter aortic valve implantation (TAVI). We investigated the dynamics of these conduction blocks to further understand luxating factors and predictors for their persistency. Materials and Methods: We prospectively included 157 consecutive patients who underwent a TAVI procedure. Electrocardiograms (ECGs) were obtained at specific time points during the TAVI procedure and at follow-up until at least six months post-procedure. Results: Of the 106 patients with a narrow QRS complex (nQRS) before TAVI, ~70% developed LBBB; 28 (26.4%) being classified as super-transient (ST-LBBB), 20 (18.9%) as transient (T-LBBB) and 24 (22.6%) as persistent (P-LBBB). Risk of LBBB was higher for self-expandable (SE) than for balloon-expandable (BE) prostheses and increased with larger implant depth. During the TAVI procedure conduction disturbances showed a dynamic behavior, as illustrated by alternating kinds of blocks in 18 cases. Most LBBBs developed during balloon aortic valvuloplasty (BAV) and at positioning and deployment of the TAVI prosthesis. The incidence of LBBB was not significantly different between patients who did and did not undergo BAV prior to TAVI implantation (65.3% and 74.2%, respectively (p = 0.494)). Progression to cAVB was most frequent for patients with preexisting conduction abnormalities (5/34) patients) and in patients showing ST-LBBB (6/28). Conclusions: During the TAVI procedure, conduction disturbances showed a dynamic behavior with alternating types of block in 18 cases. After a dynamic period of often alternating types of block, most BBBs are reversible while one third persist. Patients with ST-LBBB are most prone to progressing into cAVB. The observation that the incidence of developing LBBB after TAVI is similar with and without BAV suggests that a subgroup of patients has a substrate to develop LBBB regardless of the procedure.

Effective Distance between Aortic Valve and Conduction System Is an Independent Predictor of Persistent Left Bundle Branch Block during Transcatheter Aortic Valve Implantation

Background and objectives: Persistent left bundle branch block (P-LBBB) has been associated with poor clinical outcomes of transcatheter aortic valve implantation (TAVI) procedures. We hypothesized that the distance from the aortic valve to the proximal conduction system, expressed as the effective distance between the aortic valve and conduction system (EDACS), can predict the occurrence of P-LBBB in patients undergoing a TAVI procedure. Materials and methods: In a retrospective study, data from 269 patients were analyzed. EDACS was determined using two longitudinal CT sections. Results: Sixty-four of the patients developed P-LBBB. EDACS ranged between −3 and +18 mm. EDACS was significantly smaller in P-LBBB than in non-P-LBBB patients (4.6 (2.2–7.1) vs. 8.0 (5.8–10.2) mm, median values (interquartile range); p < 0.05). Receiver operating characteristic analysis showed an area under the curve of 0.78 for predicting P-LBBB based on EDACS. In patients with EDACS of ≤3 mm and >10 mm, the chance of developing P-LBBB was ≥50% and <10%, respectively. Conclusions: A small EDACS increases the risk for the development of P-LBBB during TAVI by a factor of >25. As EDACS can be measured pre-procedurally, it may be a valuable additional factor to weigh the risks of transcatheter and surgical aortic valve replacement.

The Vectorcardiogram and the Main Dromotropic Disturbances

Until the mid-1980s, it was believed that the vectorcardiogram (VCG) presented a greater specificity, sensitivity and accuracy in comparison to the 12-lead electrocardiogram (ECG), in the cardiology diagnosis. Currently, the VCG still is superior to the ECG in specific situations, such as in the evaluation of myocardial infarctions when associated with intraventricular conduction disturbances, in the identification and location of accessory pathways in ventricular preexcitation, in the differential diagnosis of patterns varying from normal of electrical axis deviation, in the evaluation of particular aspects of Brugada syndrome, Brugada phenocopies, concealed form of arrhythmogenic right ventricular cardiomyopathy and zonal or fascicular blocks of the right bundle branch on right ventricular free wall.VCG allows us to analyze the presence of left septal fascicular block more accurately than ECG and in the diagnosis of the interatrial blocks and severity of some chambers enlargements. The three-dimensional spatial orientation of both the atrial and the ventricular activity provides a far more complete observation tool than the linear ECG. We believe that the ECG/VCG binomial simultaneously obtained by the technique called electro-vectorcardiography (ECG/VCG) brought a significant gain for the differential diagnosis of several pathologies. Finally, in the field of education and research, VCG provided a better and more rational tridimensional insight into the electrical phenomena that occurs spatially, and represented an important impact on the progress of electrocardiography.

New-onset left bundle branch block after transcatheter aortic valve replacement is associated with adverse long-term clinical outcomes in intermediate-risk patients: an analysis from the PARTNER II trial

Aims

Transcatheter aortic valve replacement (TAVR) is now an established therapy for intermediate-risk surgical candidates with symptomatic, severe aortic stenosis. The clinical impact of new-onset left bundle branch block (LBBB) after TAVR remains controversial and has not been studied in intermediate-risk patients. We therefore sought to analyse outcomes associated with new LBBB in a large cohort of intermediate-risk patients treated with TAVR.

Methods and results

A total of 2043 patients underwent TAVR in the PARTNER II trial and S3 intermediate-risk registry and survived to hospital discharge. Patients were excluded from the current analysis due to baseline conduction disturbances, pre-existing permanent pacemaker (PPM), and new PPM during the index hospitalization. Clinical outcomes at 2 years were compared between patients with and without persistent, new-onset LBBB at hospital discharge, and multivariable analysis was performed to identify predictors of mortality. Among 1179 intermediate-risk patients, new-onset LBBB at discharge occurred in 179 patients (15.2%). Patients with new LBBB were similar to those without except for more frequent diabetes and more frequent treatment with SAPIEN 3 vs. SAPIEN XT. At 2 years, new LBBB was associated with increased rates of all-cause mortality (19.3% vs. 10.8%, P = 0.002), cardiovascular mortality (16.2% vs. 6.5%, P < 0.001), rehospitalization, and new PPM implantation. By multivariable analysis, new LBBB remained an independent predictor of 2-year all-cause [hazard ratio (HR) 1.98, 95% confidence interval (95% CI) 1.33, 2.96; P < 0.001] and cardiovascular (HR 2.66 95% CI 1.67, 4.24; P < 0.001) mortality. New LBBB was also associated with worse left ventricular systolic function at 1 and 2-year follow-up.

Conclusions

In a large cohort of intermediate-risk patients from the PARTNER II trial and registry, persistent, new-onset LBBB occurred in 15.2% of patients without baseline conduction disturbances or pacemaker. New LBBB was associated with adverse clinical outcomes at 2 years, including all-cause and cardiovascular mortality, rehospitalization, new pacemaker implantation, and worsened left ventricular systolic function.

Clinical Trial Registration

ClinicalTrials.gov #NCT01314313 and NCT03222128.

Left bundle branch block: Epidemiology, etiology, anatomic features, electrovectorcardiography, and classification proposal

In left bundle branch block (LBBB), the ventricles are activated in a sequential manner with alterations in left ventricular mechanics, perfusion, and workload resulting in cardiac remodeling. Underlying molecular, cellular, and interstitial changes manifest clinically as changes in size, mass, geometry, and function of the heart. Cardiac remodeling is associated with progressive ventricular dysfunction, arrhythmias, and impaired prognosis. Clinical and diagnostic notions about LBBB have evolved from a simple electrocardiographic alteration to a critically important finding affecting diagnostic and clinical management of many patients. Advances in cardiac magnetic resonance imaging have significantly improved the assessment of patients with LBBB and provided additional insights into pathophysiological mechanisms of left ventricular remodeling. In this review, we will discuss the epidemiology, etiologies, and electrovectorcardiographic features of LBBB and propose a classification of the conduction disturbance.

Incidence, indications and predicting factors of permanent pacemaker implantation after transcatheter aortic valve implantation: A retrospective study

BACKGROUND

As the number of transcatheter aortic valve implantation (TAVI) procedures is constantly increasing, it is important to consider common complications, such as pacemaker (PM) implantation, and their specific risk factors.

AIMS

Echocardiographic, computed tomography and electrocardiographic data were analysed to determine the predicting factors, if any, associated with PM implantation.

METHODS

This retrospective study included patients referred to Nancy University Hospital for a TAVI procedure from January 2013 to December 2015. Both Medtronic CoreValve and Edwards SAPIEN valves were implanted. Patients with preprocedurally implanted PMs and/or referred from another institution were excluded.

RESULTS

Of 208 TAVI patients, 23 had a pre-existing PM and were excluded. A new PM was required in 38 patients (20.5%). Pre-existing right bundle branch block (RBBB), the use of the Medtronic CoreValve and large prostheses were identified as predictors of PM implantation (P=0.0361, P=0.0004 and P=0.0019, respectively). Using logistic regression, predictors of PM implantation included first-degree atrioventricular block (odds ratio 3.7, 95% confidence interval 1.5-9.1; P=0.0054) and large aortic annulus diameter in echocardiography (odds ratio 1.2, 95% confidence interval 1-1.4; P=0.0447), with a threshold of 24.1mm. For the combination of preTAVI PR duration >220ms and QRS duration >120ms, the positive predictive value for PM implantation reached 80%.

CONCLUSION

Use of the Medtronic CoreValve, RBBB and first-degree atrioventricular block are major risk factors for post-TAVI PM implantation. In addition, large aortic annulus and large valvular prosthesis are independent risk factors for PM implantation. The combination of preTAVI prolonged PR interval and increased QRS duration could be used as a marker for periprocedural PM implantation.

The impact of trans-catheter aortic valve replacement induced left-bundle branch block on cardiac reverse remodeling

BACKGROUND

Left bundle branch block (LBBB) is common following trans-catheter aortic valve replacement (TAVR) and has been linked to increased mortality, although whether this is related to less favourable cardiac reverse remodeling is unclear. The aim of the study was to investigate the impact of TAVR induced LBBB on cardiac reverse remodeling.

METHODS

48 patients undergoing TAVR for severe aortic stenosis were evaluated. 24 patients with new LBBB (LBBB-T) following TAVR were matched with 24 patients with a narrow post-procedure QRS (nQRS). Patients underwent cardiovascular magnetic resonance (CMR) prior to and 6 m post-TAVR. Measured cardiac reverse remodeling parameters included left ventricular (LV) size, ejection fraction (LVEF) and global longitudinal strain (GLS). Inter- and intra-ventricular dyssynchrony were determined using time to peak radial strain derived from CMR Feature Tracking.

RESULTS

In the LBBB-T group there was an increase in QRS duration from 96 ± 14 to 151 ± 12 ms (P < 0.001) leading to inter- and intra-ventricular dyssynchrony (inter: LBBB-T 130 ± 73 vs nQRS 23 ± 86 ms, p < 0.001; intra: LBBB-T 118 ± 103 vs. nQRS 13 ± 106 ms, p = 0.001). Change in indexed LV end-systolic volume (LVESVi), LVEF and GLS was significantly different between the two groups (LVESVi: nQRS -7.9 ± 14.0 vs. LBBB-T -0.6 ± 10.2 ml/m2, p = 0.02, LVEF: nQRS +4.6 ± 7.8 vs LBBB-T -2.1 ± 6.9%, p = 0.002; GLS: nQRS -2.1 ± 3.6 vs. LBBB-T +0.2 ± 3.2%, p = 0.024). There was a significant correlation between change in QRS and change in LVEF (r = -0.434, p = 0.002) and between change in QRS and change in GLS (r = 0.462, p = 0.001). Post-procedure QRS duration was an independent predictor of change in LVEF and GLS at 6 months.

CONCLUSION

TAVR-induced LBBB is associated with less favourable cardiac reverse remodeling at medium term follow up. In view of this, every effort should be made to prevent TAVR-induced LBBB, especially as TAVR is now being extended to a younger, lower risk population.

Conduction disturbances after transcatheter aortic valve implantation procedures - predictors and management

Transcatheter aortic valve implantation (TAVI) has become a safe and efficient alternative to cardiac surgery in patients with severe aortic stenosis. In many countries the number of performed TAVI procedures equals the number of surgical implantations. Indications for TAVI are becoming more liberal, allowing a wider spectrum of patients to benefit from the advantages of transcatheter therapy. Due to its invasive nature, TAVI is associated with some complications such as conduction disturbances. Although these disturbances are usually not lethal, they have a great influence on patients’ state and long term-survival. The most relevant and common are His’ bundle branch blocks, atrioventricular blocks, and need for permanent pacemaker implantation. With the frequency at 10% to even 50%, conduction abnormalities are among the most important TAVI-related adverse events. Risk factors for conduction disturbances include age, anatomy of the heart, periprocedural factors, type of implanted valve, and comorbidities. Severity of occurring complications varies; therefore selection of a proper treatment approach is required. Considered as the most effective management, permanent pacemaker implantation turned out to negatively influence both recovery and survival. Moreover, there is no expert consensus on use of resynchronization therapy after TAVI. In this paper, the authors present a comprehensive analysis of the most common conduction disturbances accompanying TAVI, factors related to their occurrence, and treatment approach.

Episodic Left Bundle Branch Block-A Comprehensive Review of the Literature

Episodic (transient/ intermittent) left bundle branch block (LBBB) has been associated with different conditions such as bradycardia, tachycardia, anesthesia, acute pulmonary embolism, changes in intrathoracic pressure, chest trauma, cardiac interventional procedures, mad honey poisoning, and in other clinical settings. Of note, exclusion of an acute coronary syndrome in the setting of episodic LBBB is of great importance. Moreover, episodic LBBB is sometimes symptomatic and may be associated with left ventricular systolic and/or diastolic dysfunction or conduction disturbances leading to syncope. This review article provides a comprehensive overview of the conditions associated with episodic LBBB and discusses the clinical impact of this phenomenon.

Influence of QRS infarct score and QRS duration prior to transcatheter aortic valve replacement on follow-up left ventricular end systolic volume in patients with new persistent left bundle branch block

BACKGROUND

New-onset left bundle branch block (LBBB) is a known complication during Transcatheter Aortic Valve Replacement (TAVR). This study evaluated the influence of pre-TAVR cardiac conditions on left ventricular functions in patients with new persistent LBBB post-TAVR.

METHODS

Only 11 patients qualified for this study because of the strict inclusion criteria. Pre-TAVR electrocardiograms were evaluated for Selvester QRS infarct score and QRS duration, and left ventricular end-systolic volume (LVESV) was used as outcome variable.

RESULTS

There was a trend towards a positive correlation between QRS score and LVESV of r=0.59 (p=0.058), while there was no relationship between QRS duration and LVESV (r=-0.18 [p=0.59]).

CONCLUSION

This study showed that patients with new LBBB and higher pre-TAVR QRS infarct score may have worse post-TAVR left ventricular function, however, pre-TAVR QRS duration has no such predictive value. Because of the small sample size these results should be interpreted with caution and assessed in a larger study population.