New-Onset Left Bundle Branch Block After TAVI has a Deleterious Impact on Left Ventricular Systolic Function

Incidence and management of atrioventricular conduction disorders in new-onset left bundle branch block after TAVI: A prospective multicenter study

BACKGROUND

New-onset left bundle branch block (LBBB) is one of the most frequent complications after transcatheter aortic valve implantation (TAVI) and is associated with delayed high degree atrioventricular (AV) block.

OBJECTIVES

The objectives of this study were to determine the incidence of AV block in such a population and to assess the performance and safety of a risk stratification algorithm on the basis of electrophysiology study (EPS) followed by implantation of a pacemaker or implantable loop recorder (ILR).

METHODS

This was a prospective open-label study with 12-month follow-up. From June 8, 2015, to November 8, 2018, 183 TAVI recipients (mean age 82.3 ± 5.9 years) were included at 10 centers. New-onset LBBB after TAVI persisting for >24 hours was assessed by electrophysiology study during initial hospitalization. High-risk patients (His-ventricle interval ≥70 ms) were implanted with a dual-chamber pacemaker recording AV conduction disturbance episodes. Patients at lower risk were implanted with an ILR with automatic remote monitoring.

RESULTS

A high-grade AV conduction disorder was identified in 56 patients (30.6%) at 12 months. Four subjects were symptomatic, all in the ILR group. No complications were associated with the stratification procedure. Patients with His-ventricle interval ≥70 ms displayed more high-grade AV conduction disorders (53.2% [25 of 47] vs 22.8% [31 of 136]; P < .001). In a multivariate analysis, His-ventricle interval ≥70 ms was independently associated with the occurrence of a high-grade conduction disorder (subdistribution hazard ratio 2.4; 95% confidence interval 1.2-4.8; P = .010).

CONCLUSION

New-onset LBBB after TAVI was associated with high rates of high-grade AV conduction disturbances. The stratification algorithm provided safe and valuable aid to management decisions and reliable guidance on pacemaker implantation.

Effects of Left Bundle Branch Block and Pacemaker Implantation on Left Ventricular Systolic Function After Transcatheter Aortic Valve Implantation

Permanent pacemaker implantation (PPI) and left bundle branch block (LBBB) frequency after transcatheter aortic valve implantation (TAVI) and their effect on left ventricular ejection fraction (LVEF) remain controversial. We evaluated the incidence of PPI and new-onset LBBB after TAVI and their impact on LVEF at 6-month follow-up. Moreover, the impact of right ventricular (RV) pacing burden on changes in LVEF after TAVI was analyzed. The electrocardiograms of 377 patients (age 80 ± 7 years, 52% male) treated with TAVI were collected at baseline, after the procedure, at discharge, and at each outpatient follow-up. LVEF was measured at baseline before TAVI and 6 months after the procedure. Patients were divided into 3 groups according to the occurrence of LBBB, the need for PPI, or the absence of new conduction abnormalities. In patients with PPI, the influence of RV pacing burden on LVEF was analyzed. New-onset LBBB after TAVI occurred in 92 patients (24%), and PPI was required in 55 patients (15%). In patients without new conduction abnormalities, LVEF significantly increased during follow-up (56 ± 14% to 61 ± 12%, p <0.001). Patients with a baseline LVEF ≤50% presented with a significant recovery in LVEF, although the recovery was less pronounced in patients with new-onset LBBB. Moreover, patients with a baseline LVEF ≤50% who received PPI showed an improvement in LVEF at 6 months regardless of the RV pacing burden. New-onset LBBB hampers the recovery of LVEF after TAVI. Among patients with an LVEF ≤50%, pressure overload relief counteracts the effects of new-onset LBBB or RV pacing.

Prognostic Outcome of New-Onset Left Bundle Branch Block After Transcatheter Aortic Valve Replacement in Patients With Aortic Stenosis: A Systematic Review and Meta-Analysis

Background

Left bundle branch block (LBBB) is a common complication of the transcatheter aortic valve replacement (TAVR), and its impact on prognosis is controversial.

Methods

A comprehensive electronic search was conducted in databases (PubMed, Embase, Cochrane Library, and The Web of Science), from the date of database establishment till March 2021, to screen for studies on new-onset LBBB after TAVR. We next performed a meta-analysis to evaluate the effect of new-onset LBBB after TAVR on patient prognosis, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

A total of 17 studies, including 9205 patients, were eligible for our analysis. Patients with new-onset LBBB had elevated all-cause mortality risk verses patients without new-onset LBBB, during all follow ups. The relevant data are as follows: 30-day (RR:1.71; 95%CI:1.27–2.29; P &lt; 0.001), 1-year (RR:1.31; 95%CI:1.12–1.52; P &lt; 0.001), and 2-year (RR:1.31; 95%CI:1.09–1.56; P = 0.003) follow ups. Likewise, new-onset LBBB patients also experienced increased cardiovascular mortality, compared to non-new-onset LBBB patients, but only in the 1-year follow up (RR:1.49; 95%CI:1.23–1.82; P &lt; 0.001). Hospitalization for heart failure was dramatically elevated in patients with new-onset LBBB verses non-new-onset LBBB, in all follow ups. The relevant data are as follows: 30-day (RR:1.56; 95%CI:1.13–2.12; P = 0.007), 1-year (RR:1.35; 95%CI:1.08–1.68; P = 0.007), and 2-year (RR:1.49; 95%CI:1.21–1.84; P &lt; 0.001). Similarly, new-onset LBBB patients had higher PPI risk than non-new-onset LBBB patients, in all follow ups. The relevant data are as follows: 30-day (RR:3.05; 95%CI:1.49–6.22; P = 0.002), 1-year (RR:2.15; 95%CI:1.52–3.03; P &lt; 0.001), and 2-year (RR:2.52; 95%CI:1.68–3.78; P &lt; 0.001).

Conclusion

Patients with new-onset LBBB have worse prognosis after TAVR than those without new-onset LBBB. Recognition of the adverse effects of post-TAVR new-onset LBBB can lead to the development of new strategies that enhance clinical outcomes.

Systematic Trial Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=197224, identifier: 19722.

Advantages and disadvantages of drug challenge during electrophysiological study in patients with new left bundle branch block after transaortic valve implantation

AIMS

Electrophysiological study (EPS) is recommended in case of new-onset persistent left bundle branch block (NOP-LBBB) after transaortic valve implantation (TAVI) to identify patients at high risk of delayed atrioventricular block (D-AVB). We evaluated the added value of drug challenge, after normal baseline EPS, to predict D-AVB in such patients.

METHODS

We conducted a comparative single-centre study of two successive periods, during which we used baseline EPS alone (first period) or drug challenge in case of normal baseline EPS (second period), for patients with NOP-LBBB after TAVI. The primary endpoint was a composite of pacemaker use, documented D-AVB, cardiac syncope, sudden death, or delayed pacemaker implantation.

RESULTS

Among 736 patients with TAVI implantation between January 2016 and September 2019, 64 with NOP-LBBB were included. During the first period, 4/22 (18.2%) presented with a positive baseline EPS. After a mean (standard deviation [SD]) of 15.6 (8.3) months, 7/22 (31.8%) reached the primary endpoint. During the second period, 19/42 (45.2%) presented with a positive EPS. After a mean (SD) of 12.8 (3.5) months, 8/42 (19.0%) reached the primary endpoint. There was a tendency to increased sensitivity (42.9-87.5%; P = 0.12) and negative predictive value (77.8-95.7%; P = 0.15) of the EPS, respectively during the first to the second period. However, the specificity decreased (93.3-64.7%; P = 0.04).

CONCLUSION

Diagnostic yield improved with drug challenge in case of normal baseline EPS. However, the decrease in specificity led to a high rate of unnecessary pacemaker implantation.

Intraprocedural dynamics of cardiac conduction during transcatheter aortic valve implantation: Assessment by simultaneous electrophysiological testing

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is an established treatment for patients with severe aortic stenosis and high to intermediate surgical risk. However, the proximity of the conduction system to the prosthesis landing zone bears the risk of atrioventricular conduction disorders. The underlying pathophysiology is not fully understood.

OBJECTIVE

The purpose of this study was to characterize the impact of TAVI on the conduction system as assessed by simultaneous electrophysiological testing.

METHODS

AH and HV intervals and QRS duration were measured using a quadripolar His catheter and surface electrocardiogram in 108 patients at baseline (BL), after balloon predilation (timepoint 1 [T1]), after implantation of the valve prosthesis (T2), and after postdilation, if deemed necessary (T3).

RESULTS

Between BL and T2, significant increases of HV interval and QRS duration were observed, with a mean delta of +12.4 ms and +32.7 ms, respectively. Both balloon predilation and valve implantation had an impact on infranodal conduction. No significant increase of AH intervals was documented. The increase of QRS duration led to left bundle branch block (LBBB) in 57 patients (52.8%). Implantation depth positively correlated with QRS prolongation (ρ = 0.21, P = .042) but not with changes of AH or HV interval (ρ = -0.03, P = .762; and ρ = 0.15, P = .130, respectively).

CONCLUSION

Electrophysiological testing during TAVI shows impairment of infranodal atrioventricular conduction by balloon predilation and valve implantation. This impairment is positively correlated with valve implantation depth and results in an increase of QRS duration with mainly LBBB pattern on surface electrocardiogram.