Pre-existing Left Bundle Branch Block Research Articles

Conduction system disease management in patients candidate and/or treated for the aortic valve disease: an Italian Survey promoted by Italian Association of Arrhythmology and Cardiac Pacing (AIAC)

Background Conduction system disorders represent a frequent complication in patients undergoing surgical (surgical aortic valve replacement, SAVR) or percutaneous (transcatheter aortic valve implantation, TAVI) aortic valve replacement. The purpose of this survey was to evaluate experienced operators approach in this clinical condition. Methods This survey was independently conducted by the Italian Association of Arrhythmology and Cardiac Pacing (AIAC) and it consisted of 24 questions regarding the respondents’ profile, the characteristics of participating centres, and conduction disease management in different scenarios. Results Fifty-five physicians from 55 Italian arrhythmia centres took part in the survey. Prophylactic pacemaker implantation is rare. In case of persistent complete atrioventricular block (AVB), 49% and 73% respondents wait less than one week before implanting a definitive pacemaker after SAVR and TAVI, respectively. In case of second degree AVB, the respondents wait some days more for definitive implantation. Respondents consider bundle branch blocks, in particular pre-existing left bundle branch block (LBBB), the worst prognostic factors for pacemaker implantation after TAVI. The implanted valve type is considered a relevant element to evaluate. In patients with new-onset LBBB and severe/moderate left ventricular systolic dysfunction, respondents would implant a biventricular pacemaker in 100/55% of cases, respectively. Conclusions Waiting time before a definitive pacemaker implantation after aortic valve replacement has reduced compared to the past, and it is anticipated in TAVI vs. SAVR. Bundle branch blocks are considered the worse prognostic factor for pacemaker implantation after TAVI. The type of pacemaker implanted in new-onset LBBB patients without severe left ventricular systolic dysfunction is heterogeneous.

Pre-Existing Left Bundle Branch Block and Clinical Outcomes After Transcatheter Aortic Valve Replacement

BackgroundFew reports on pre-existing left bundle branch block (LBBB) in patients undergoing transcatheter aortic valve replacement (TAVR) are currently available. Further, no present studies compare patients with new onset LBBB with those with pre-existing LBBB. ObjectivesThis study aimed to investigate the association between pre-existing or new onset LBBB and clinical outcomes after TAVR. MethodsUsing data from the Japanese multicenter registry, 5,996 patients who underwent TAVR between October 2013 and December 2019 were included. Patients were classified into 3 groups: no LBBB, pre-existing LBBB, and new onset LBBB. The 2-year clinical outcomes were compared between 3 groups using Cox proportional hazards models and propensity score analysis to adjust the differences in baseline characteristics. ResultsOf 5,996 patients who underwent TAVR, 280 (4.6%) had pre-existing LBBB, while 1,658 (27.6%) experienced new onset LBBB. Compared with the no LBBB group, multivariable Cox regression analysis showed that pre-existing LBBB was associated not only with a higher 2-year all-cause (adjusted HR: 1.39; 95% CI: 1.06-1.82; P = 0.015) and cardiovascular (adjusted HR: 1.60; 95% CI: 1.04-2.48; P = 0.031) mortality, but also with higher all-cause (adjusted HR: 1.43, 95% CI: 1.07-1.91; P = 0.016) and cardiovascular (adjusted HR: 1.81, 95% CI:1.12-2.93; P = 0.014) mortality than the new onset LBBB group. Heart failure was the most common cause of cardiovascular death, with more heart failure deaths in the pre-existing LBBB group. ConclusionsPre-existing LBBB was independently associated with poor clinical outcomes, reflecting an increased risk of cardiovascular mortality after TAVR. Patients with pre-existing LBBB should be carefully monitored.

Predictors of permanent pacemaker implantation after transcatheter aortic valve implantation - Results from the SOLVE-TAVI trial

Abstract Background Permanent pacemaker implantation (PPI) is frequently required following transcatheter aortic valve implantation (TAVI). However, the predisposing parameters increasing the likelihood of severe conduction abnormalities are still not fully understood. Purpose To analyze predictors of PPI 30 days after TAVI. Methods The SOLVE-TAVI trial randomized 447 patients to TAVI using either the balloon-expandable Edwards Sapien 3 valve or the self-expanding Medtronic Evolut R valve. Pacemaker rates at 30 days were relatively high, but comparable between both transcatheter heart valve (THV) types (19% vs. 23%). Computed tomography (CT) scans were analyzed semi-automatically to determine aortic annulus size and subannular calcification. The percentage of THV oversizing was calculated using the formula (nominal THV circumference/annular circumference – 1) x 100). Results From all patients treated with either the Sapien 3 or Evolut R valve, 47 patients were excluded because of prior pacemaker implantation. Rates of new PPI at 30 days were similar in patients with and without pre-existing left bundle branch block (7/36 patients vs. 53/342 patients, p=0.48) and right bundle branch block (11/51 patients vs. 48/327 patients, p=0.22), without significant differences according to valve type. Patients with new PPI showed a significantly higher degree of THV oversizing compared to patients without PPI (median 15%, interquartile range [IQR] 9-20% vs. median 12%, IQR 7-17%; p=0.03). Moderate/severe compared to no/mild subannular calcification did not result in higher PPI rates (17/121 patients vs. 40/245 patients; p=65). Conclusion THV oversizing but not pre-existing left and right bundle branch block and subannular calcification is associated with PPI after TAVI.

Management of Postprocedural Conduction Disturbances Using a Prespecified Algorithm in the Optimize PRO Study

BackgroundLack of standardization in posttranscatheter aortic valve replacement (TAVR) conduction disturbance (CD) identification and treatment may affect permanent pacemaker implantation (PPI) rates and clinical outcomes. The safety and efficacy of a standardized TAVR CD algorithm has not been analyzed. This study analyzes the Optimize PRO post-TAVR CD management algorithm with Evolut PRO/PRO+ valves. MethodsOptimize PRO is a prospective, postmarket study implementing 2 strategies to reduce pacemaker rates: TAVR with cusp overlap technique and a post-TAVR CD algorithm. The 2-hour postprocedural electrocardiogram (ECG) stratified patients to early discharge in the absence of new ECG changes or to CD algorithms for (1) ECG changes with preexisting right or left bundle branch block (LBBB), interventricular conduction delay or first-degree atrioventricular block, (2) new LBBB, or (3) high-degree atrioventricular block (HAVB). ResultsThe interim analysis of the CD cohort consisted of 125/400 TAVR recipients. In the CD cohort, the 30-day new PPI rate was higher (28.1% vs 1.5%; P <.001), and 60 (48%) patients were discharged with a 30-day continuous ECG monitor. At 30 days, 90% of patients discharged with a monitor did not require PPI. Clinical outcomes, including mortality, stroke, bleeding, and reintervention, were similar in patients with and without CDs. No patient experienced sudden cardiac death. ConclusionsEffective management of CDs using a standard algorithm following Evolut TAVR provides similar 30-day safety outcomes to patients without CDs who undergo routine next day discharge. The CD algorithm may provide an effective strategy to recognize arrhythmias early, improve PPI utilization, and facilitate safe monitoring of patients after discharge.

Effect of acute CORticosteroids on conduction defects after Transcatheter Aortic Valve Implantation: the CORTAVI study.

Conduction abnormalities, requiring a permanent pacemaker (PPM), are the most common electrical complications after transcatheter aortic valve implantation (TAVI). The exact mechanism for conduction system defects is not yet clear. The local inflammatory process and edema are thought to play a role in the development of electrical disorders. Corticosteroids are effective anti-inflammatory and antiedematous agents. We aim to investigate the potential protective effect of corticosteroids on conduction defects after TAVI. This is a retrospective study of a single center. We analyzed 96 patients treated with TAVI. Thirty-two patients received oral prednisone 50 mg for 5 days after the procedure. This population was compared with the control group. All patients were followed up after 2 years. Of the 96 patients included, 32 (34%) were exposed to glucocorticoids after TAVI. No differences in age, preexisting right bundle branch block or left bundle branch block, or valve type were seen among patients exposed to glucocorticoids versus those who were unexposed. We observed no significant differences between the two groups in the overall frequency of new PPM implantations during hospitalization (12% vs. 17%, P = 0.76). The incidence of atrioventricular block (AVB) (STx 9% vs. non-STx 9%, P = 0.89), right bundle branch block (STx 6% vs. non-STx 11%, P = 0.71), and left bundle branch block (STx 34% vs. non-STx 31%, P = 0.9) was not significantly different between the STx and non-STx groups. At 2 years after TAVI, none of the patients had implanted PPM or had severe arrhythmias documented by 24-h Holter ECG or cardiac examination. Oral prednisone treatment does not appear to significantly reduce the incidence of AVB requiring acute PPM implantation after TAVI.

Ventricular pacing burden in patients with left bundle branch block after transcatheter aortic valve replacement therapy.

Electrophysiological testing has been proposed in the latest European Society of Cardiology (ESC) guidelines for cardiac pacing to identify left bundle branch block (LBBB) patients with infrahisian conduction delay (IHCD) after transcatheter aortic valve replacement (TAVR). While in general IHCD is defined by a His-ventricular (HV) interval of >55 ms, a cut-off of ≥70 ms to trigger pacemaker (PM) implantation has been proposed in the latest ESC guidelines. The ventricular pacing (VP) burden during follow-up in such patients is largely unknown. As such, we aimed to assess the VP burden during follow-up of patients receiving PM therapy for LBBB after TAVR based on an HV interval > 55 ms and ≥70 ms. All patients with new-onset or pre-existing LBBB after undergoing TAVR at a tertiary referral center underwent EP testing the day after TAVR. In patients with a prolonged HV interval (>55 ms), PM implantation was performed by a trained electrophysiologist in a standardized fashion. All devices were programmed to avoid unnecessary VP by specific algorithms (e.g., AAI-DDD). 701 patients underwent TAVR at the University Hospital of Basel. One hundred seventy-seven patients presented with new-onset or pre-existing LBBB the day following TAVR and underwent EP testing. An HV interval > 55 ms was found in 58 patients (33%) and an HV interval ≥ 70 ms in 21 patients (12%). 51 patients (mean age 84 ± 6.2 years, 45% women) agreed to receive a PM, out of which 20 (39%) patients had an HV Interval over 70 ms. Atrial fibrillation was present in 53% of the patients. A dual chamber PM was implanted in 39 (77%), and a single chamber PC in 12 (23%) patients, respectively. Median follow-up was 21 months. The median VP burden overall was 3%. The median VP burden was not significantly different between patients with an HV ≥ 70 ms (6.5 [0.8-52]) and those with an HV between 55 and 69 ms (2 [0-17], p = .23). 31% of patients demonstrated a VP burden < 1%, 27% 1%-5% and 41% > 5%. The median HV intervals in patients with VP burdens < 1%, 1%-5% and >5% were 66 (IQR 62-70) ms, 66 (IQR 63-74) ms and 68 (IQR 60-72) ms, respectively, p = .52. When only assessing patients with an HV interval 55-69 ms, 36% demonstrated a VP burden of <1%, 29% of 1%-5% and 35% of >5%. In patients with an HV Interval ≥ 70 ms, 25% demonstrated a VP burden < 1%, 25% of 1%-5% and 50% of >5% %, p = .64 (Figure). In patients with LBBB after TAVR and IHCD defined by an HV interval > 55 ms, VP burden is relevant in a non-negligible amount of patients during follow-up. Further studies are warranted to define the optimal cut-off value for the HV interval or to develop risk models incorporating HV measurements and other risk factors to trigger PM implantation in patients with LBBB after TAVR.

Incidence of infranodal conduction delay in patients with left bundle branch block after transcatheter aortic valve replacement: Impact of the 2021 ESC guidelines for cardiac pacing

The occurrence of left bundle branch block (LBBB) after transcatheter aortic valve replacement (TAVR) remains the most frequent complication of the procedure. 1 Khatri P.J. Webb J.G. Rodés-Cabau J. et al. Adverse effects associated with transcatheter aortic valve implantation: a meta-analysis of contemporary studies. Ann Intern Med. 2013; 158: 35-46 Crossref PubMed Scopus (210) Google Scholar ,2 Badertscher P. Knecht S. Zeljković I. et al. Management of conduction disorders after transcatheter aortic valve implantation: results of the EHRA survey. Europace. 2022; 24: 1179-1185 Crossref PubMed Scopus (0) Google Scholar Electrophysiological (EP) testing is recommended with a class IIa indication in the new 2021 European Society of Cardiology (ESC) guidelines for cardiac pacing 3 Glikson M. Nielsen J.C. Kronborg M.B. et al. 2021 ESC guidelines on cardiac pacing and cardiac resynchronization therapy. Eur Heart J. 2021; 42: 3427-3520 Crossref PubMed Scopus (384) Google Scholar in patients having new LBBB with QRS ≥150 ms or PR ≥240 ms or with pre-existing LBBB with a delta of QRS/PR intervals ≥20 ms after TAVR. A cutoff for HV interval ≥70 ms to consider pacemaker (PM) implantation was suggested. However, evidence for these proposed cutoffs of HV interval, QRS duration, and PR interval is scarce in LBBB patients after TAVR. 4 Jørgensen T.H. de Backer O. Gerds T.A. et al. Immediate post-procedural 12-lead electrocardiography as predictor of late conduction defects after transcatheter aortic valve replacement. JACC Cardiovasc Interv. 2018; 11: 1509-1518 Crossref PubMed Scopus (44) Google Scholar

Clinical and echocardiographic outcomes with new-onset left bundle branch block after SAPIEN-3 transcatheter aortic valve replacement.

New-onset left bundle branch block (LBBB) can develop after transcatheter aortic valve replacement (TAVR) resulting in worse outcomes. Describe clinical and echocardiographic outcomes with new-onset LBBB after TAVR. We included consecutive patients who underwent transfemoral-TAVR with SAPIEN-3 (S3) valve between April 2015 and December 2018. Exclusion criteria included pre-existing LBBB, right BBB, left anterior hemiblock, left posterior hemiblock, wide QRS ≥ 120ms, prior permanent pacemaker (PPM), and nontransfemoral access. Among 612 patients, 11.4% developed new-onset LBBB upon discharge. The length of stay was longer with new-onset LBBB compared with no LBBB [3 (2-5) days versus 2 (1-3) days; p < 0.001]. New-onset LBBB was associated with higher rates of 30-day PPM requirement (18.6% vs. 5.4%; p < 0.001) and 1-year heart failure hospitalizations (10.7% vs. 4.4%; p = 0.033). There was no difference in 3-year mortality between both groups (30.9% vs. 30.6%; p = 0.829). Further, new-onset LBBB was associated with lower left ventricular ejection fraction (LVEF) at both 30 days (55.9 ± 11.4% vs. 59.3 ± 9%; p = 0.026) and 1 year (55 ± 12% vs. 60.1 ± 8.9%; p = 0.002). These changes were still present when we stratified patients according to baseline LVEF (≥50% or <50%). New-onset LBBBs were associated with a higher 1-year LV end-diastolic volume index (51.4 ± 18.6 vs. 46.4 ± 15.1 ml/m2 ; p = 0.036), and LV end-systolic volume index (23.2 ± 14.1 vs. 18.9 ± 9.7 ml/m2 ; p = 0.009). Compared with resolved new-onset LBBB, persistent new-onset LBBB was associated with worse LVEF and higher PPM at 1 year. New-onset LBBB after S3 TAVR was associated with higher PPM requirement, worse LVEF, higher LV volumes, and increased heart failure hospitalizations, with no difference in mortality.

Delta Increment in Pacing QRS Duration Predicts Cardiovascular Mortality in Patients with Pre-Existing Bundle Branch Block Receiving Permanent Pacemakers.

The clinical implication of pre-existing intraventricular conduction disturbance (IVCD) in permanent pacemaker (PPM) recipients is unknown. To explore the clinical outcomes in patients with pre-existing IVCD after implantation of PPMs. A total of 1424 patients who received PPMs were categorized into three groups by pre-procedural electrocardiography: patients without IVCD (n = 1045), patients with right bundle branch block (RBBB) (n = 309), and patients with left bundle branch block (LBBB) (n = 70). The primary outcome was cardiovascular (CV) mortality. Receiver operating characteristic curve analysis was performed to determine the optimal cut-off values of variable in predicting CV mortality. During follow-up, there was no significant difference in CV mortality between patients with and without IVCD. In multivariate analysis, independent predictors of CV mortality were age [hazard ratio (HR): 1.03; 95% confidence interval (95% CI): 1.00-1.05; p = 0.026], history of heart failure [HR: 1.98; 95% CI: 1.19-3.29; p = 0.009], chronic kidney disease [HR: 1.75; 95% CI: 1.11-2.74; p = 0.015] and increment in pacing QRS duration [HR: 1.01; 95% CI: 1.00-1.04; p = 0.038]. Delta increments in pacing QRS duration ≥ 43 msec [HR: 2.91; 95% CI: 1.23-6.83; p = 0.014] in patients with pre-existing RBBB, and ≥ 33 msec [HR: 11.44; 95% CI: 2.03-64.30; p = 0.006] in patients with pre-existing LBBB were independent determinants of CV mortality. There was no difference in CV mortality between patients with or without IVCD. However, wider pacing QRS duration increased the risk of CV mortality in PPM recipients, and delta increment in pacing QRS duration increased the risk of CV mortality in patients with pre-existing IVCD.

Durability of left bundle branch area pacing.

Left bundle branch area pacing (LBBAP) is a form of conduction system pacing. Long-term data on the safety and performance of LBBAP 1 year postdevice implantation has not been well described. Sixty-five patients (49% females) who received LBBAP for bradycardia indications using the SelectSecure 3830 lead (Medtronic) were retrospectively evaluated. Clinical variables were examined. Lead parameters were obtained at implant and during regular follow-up. Mean age of patients was 75.7 ± 10.1 years with left ventricular ejection fraction 59.8 ± 10.4%. Indications for pacing were atrioventricular block 55%, sinus node dysfunction 19%, tachy-brady syndrome 15%, atrioventricular node ablation 8%, and bail out cardiac resynchronization therapy 3%. Mean baseline QRS measured 120 ± 38 ms, paced QRS duration was 138 ± 22ms. Paced QRS narrowed by 24 ms in those with pre-existing left bundle branch block (BBB), increased by 1 ms in those with pre-existing right BBB, and increased by 42 ms in those with no BBB. LBBAP threshold at implant was 0.521 ± 0.153 V at 0.4 ms, and increased to 0.654 ± 0.186 V at 3 months (+26%), 0.707 ± 0.186 V at 6 months (+36%), and 0.772 ± 0.220 V at 12 months (+48%). Patients with left BBB showed the maximum benefit with QRS narrowing 24 ms. Pacing impedance remained unchanged with no procedure-related complications. LBBAP is a durable form of conduction system pacing with pacing thresholds remaining relatively stable over 12 months post device implantation. Patients with left BBB display the narrowest paced QRS.

Changes of the non-invasive myocardial work in patient undergoing transcatheter aortic valve replacement: the influence of left bundle branch block

Abstract Funding Acknowledgements Type of funding sources: None. Patients with left bundle branch block (LBBB) are known to have substantially increased afterload sensitivity. It gains particular importance in subjects with aortic stenosis: patients with pre-existing LBBB may benefit more from interventions such as transcatheter aortic valve replacement (TAVR) by an effective and rapid reduction of the left ventricular (LV) pressures. Accordingly, our aim was to investigate the changes of LV myocardial work indices in patients undergoing TAVR by the presence of preoperative LBBB. Non-invasive myocardial work indices are novel echocardiographic parameters which adjust LV deformation to the instantaneous LV pressure, overcoming the the load-sensitivity of the traditional LV functional measures. Thirty patients undergoing TAVR were enrolled (37% female; age: 78±6 years; aortic valve area [AVA]: 0.7±0.3 cm2). Fourteen patients (47%; LBBB group) showed LBBB pattern on ECG, by demonstrating native LBBB (n=6; 20%) or having ventricular pacing dependency (n=8; 27%), while 16 patients had narrow QRS (53%; non-LBBB group). Prior to the procedure, subjects underwent a detailed echocardiographic investigation. Speckle-tracking analysis was performed and global longitudinal strain (GLS) was measured. LV pressure curve was estimated by adding the mean aortic valve gradient to the aortic systolic pressure. Using these measures, LV global constructive work index (CMWI) and global work efficiency (GWE). were quantified by commercially available software. A 6 months follow-up examination was also performed and at that time point we determined the aforementioned parameters. As expected, AVA significantly improved after the procedure in the pooled study group (1.8±0.4 cm2; p&amp;lt;0.001). GLS also significantly increased (-13.2±4.2 vs. -15.2±3.9 %; p&amp;lt;0.01), while CMWI only showed a tendential decrease (2422±788 vs. 2166±640 mmHg%; p=NS) at the follow-up. GLS (-10.6±3.7 vs. -15.5±3.4%; p&amp;lt;0.001), CMWI (1877±679 vs. 2898±529 mmHg%; p&amp;lt;0.001), and also GWE (82±9 vs. 91±4%; p&amp;lt;0.01) was significantly lower in the LBBB-group compared to the non-LBBB patients. At the follow-up, GLS was still significantly lower in the LBBB patients (-13.2±4.6 vs. -16.9±2.1%; p&amp;lt;0.01), however, CMWI was comparable between the two groups (1956±776 vs. 2350±439 mmHg%, p=NS). Pressure overload of the LV may affect patients with LBBB substantially more than subjects without it. TAVR causes an immediate and significant decrease in the LV afterload, which results in a more pronounced improvement in the LBBB group compared to those with no LBBB.

Long-term outcomes of new-onset conduction abnormalities following transcatheter aortic valve implantation

Previous studies provided conflicting data on the impact of new conduction abnormalities (CA), including new left bundle branch block (LBBB) and permanent pacemaker (PPM) implantation, on patient outcomes after transcatheter aortic valve implantation (TAVI). To investigate the effect of new-onset CA after TAVI on long-term clinical outcomes and the impact of new CA depending on patient baseline profile. Using data from a prospective TAVI registry (NCT01368250), patients without pre-existing LBBB or PPM were included in this study, and were stratified into three groups: no CA, new LBBB and new PPM after TAVI. Among 2370 eligible patients, 1533 (64.7%) had no CA, 336 (14.2%) had new LBBB and 501 (21.1%) had new PPM after TAVI. At 5 years, patients with new LBBB had an increased risk of all-cause death (adjusted hazard ratio [HRadjusted] 1.41, 95% confidence interval [CI] 1.04-1.92; P=0.026), whereas patients with new PPM had a numerically increased risk of mortality (HRadjusted 1.26, 95% CI 0.99-1.60; P=0.065) compared to patients without CA. There was no significant difference in cardiovascular mortality between groups (HRadjusted for new LBBB 1.33, 95% CI 0.91-1.97; P=0.15; HRadjusted for new PPM 1.25, 95% CI 0.93-1.68; P=0.13]). The adverse effects of new CA were consistent across all subgroups except for the impact of new PPM stratified by balloon-expandable versus self-expanding or mechanically expanding valves (Pinteraction=0.004). New-onset LBBB after TAVI was associated with an increased risk of 5-year all-cause mortality, while new PPM implantation conferred a non-significant trend.

Case report: Wide-complex tachycardia one week post-CRT-D implantation in a patient with pre-existing left bundle branch block

A 37-year-old female with dilated cardiomyopathy, whose baseline ECG showed sinus rhythm with left bundle branch block pattern, received a cardiac resynchronization therapy defibrillator (CRTD). One week post-implantation, she presented to the emergency department with palpitations, diaphoresis and chest discomfort. ECG showed a wide-complex tachycardia (WCT) episode, which spontaneously converted to sinus rhythm, and was later diagnosed as typical slow-fast atrioventricular nodal re-entrant tachycardia. This report outlines the differential diagnoses for WCT and the reasoning behind the eventual diagnosis, taking into consideration the device interrogation findings and results of the electrophysiology study.

Management of conduction disorders after transcatheter aortic valve implantation: results of the EHRA survey.

Conduction disorders such as left bundle branch block (LBBB) are common after transcatheter aortic valve implantation (TAVI). Consensus regarding a reasonable strategy to manage conduction disturbances after TAVI has been elusive. The European Heart Rhythm Association (EHRA) conducted a survey to capture contemporary clinical practice for conduction disorders after TAVI. A 25-item online questionnaire was developed and distributed among the EHRA electrophysiology (EP) research network centres. Of 117 respondents, 44% were affiliated with university hospitals. A standardized management protocol for advanced conduction disorders such as LBBB or atrioventricular block (AVB) after TAVI was available in 63% of participating centres. Telemetry after TAVI was chosen as the most frequent management strategy for patients with new-onset or pre-existing LBBB (79% and 70%, respectively). Duration of telemetry in patients with new-onset LBBB varied, with a 48-h period being the most frequently chosen, but almost half monitoring continued for at least 72 h. Similarly, in patients undergoing EP study due to new-onset LBBB, the HV interval cut-off point leading to pacemaker implantation was heterogeneous among European centres, although an HV >75 ms threshold was the most common. Conduction system pacing was chosen as a preferred approach by 3.7% of respondents for patients with LBBB and normal left ventricular ejection fraction (LVEF), and by 5.6% for patients with LBBB and reduced LVEF. This survey suggests some heterogenity in the management of conduction disorders after TAVI across European centres. The risk stratification strategies vary substantially. Conduction system pacing in patients with LBBB after TAVI is still underused.

Impact of pre-existing right or left bundle branch block on patients undergoing surgical aortic valve replacement.

Contemporary data on the prognostic impact of pre-existing left or right bundle branch block on clinical outcomes after aortic valve (AV) replacement are limited. The aim of this study was to evaluate the impact of pre-existing bundle branch block on clinical outcomes in patients undergoing AV replacement. Data from patients who underwent AV replacement surgery between 2004 and 2020 were obtained from our departmental database. Of the 2704 study patients, 203 (7.5%) had pre-existing bundle branch block and 2501 (92.5%) had normal atrioventricular conduction. The mean age was 68 (13) years, 1697 (63%) were male and 683 (25%) had a unicuspid or bicuspid AV. The in-hospital mortality rate was higher in patients with pre-existing bundle branch block compared to those without on admission (5.9% vs 2.9%, P = 0.032), and more frequent in patients with left compared with right bundle branch block (11.9% vs 4.3%, P = 0.003). New pacemaker implantation was most frequent in those patients with pre-existing left bundle branch block, followed by right and no bundle branch block on admission (28.6% vs 7.5% vs 2.8% respectively, P < 0.001; odds ratio 4.96 95% confidence interval 2.96-8.08, P < 0.001). The 10-year cumulative survival rate was lower in patients with bundle branch block compared with patients with no bundle branch block (76.8% vs 82.8%, log-rank P < 0.001; hazard ratio 0.73, confidence interval 0.54-0.99, P = 0.042). This study indicates that patients with pre-existing bundle branch block have a higher incidence of pacemaker implantation and all-cause mortality after AV replacement compared with patients without a conduction disturbance.

607 Comparison of incidence and predictors of new left bundle branch block and permanent pacemaker implantation in a large multicentre contemporary TAVI registry using the Evolut R/pro system vs. the accurate neo valve

Abstract Aims Conduction disorders and permanent pacemaker implantation (PPI) continue to be an important issue in patients who undergo transcatheter aortic valve implantation (TAVI). The aim of this study was to investigate the incidence and clinical outcomes of new left bundle branch block (LBBB) and PPI after TAVI in a comparison between two self-expandable supra-annular transcatheter valves. Methods and results We report the data from an international, retrospective registry including 3862 consecutive patients who underwent TAVI with two self-expanding transcatheter heart valves (Medtronic Evolut R/PRO and Boston ACURATE neo). Patients with pre-existing left or right bundle branch block, any atrioventricular blocks or previous pacemaker implantation were excluded. Finally, we performed a propensity score matched analysis (PSM) to match the patients and overcome pre-procedural differences reaching 427 couples. New-onset Left Bundle Branch Block (LBBB) occurred with a rate of 13.1% (56/427) in the ACURATE group and 18.7% (80/427) in the Evolut group (P = 0.031). The incidence of new permanent pacemaker implantation was 16.4% (70/427) in the Evolut group and 6.8% (29/427) in the ACURATE group, respectively (P &amp;lt; 0.001). In the multivariate regression analysis, we found the valve recapture [odds ratio (OR): 4.66, 95% confidence interval (CI): 1.08–23.75, P = 0.042] as significant predictors for LBBB, and male sex (OR: 1.59, CI: 1.03–2.46, P = 0.036), ACURATE valve (OR: 0.34, CI: 0.20–0.57, P &amp;lt; 0.001) and post-procedure LBBB (OR: 4.38, CI: 2.78–6.85, P &amp;lt; 0.001) for PPI. Conclusions In our large multi-centre contemporary cohort of patients, new LBBB and PPI occurred more frequently in patients following TAVI with Evolut R/PRO vs. ACURATE valve. However, the choice of the valve seemed to influence only the rate of pacemaker implantation and not the incidence of new LBBB. Further data is required to clarify the impact of valve design on conduction abnormalities.

Predictors for the risk of permanent pacemaker implantation after transcatheter aortic valve replacement: A systematic review and meta-analysis.

Transcatheter aortic valve replacement (TAVR) is a less invasive treatment than surgery for severe aortic stenosis. However, its use is restricted by the fact that many patients eventually require permanent pacemaker implantation (PPMI). This meta-analysis was performed to identify predictors of post-TAVR PPMI. The PubMed, Embase, Web of Science, and Cochrane Library databases were systematically searched. Relevant studies that met the inclusion criteria were included in the pooling analysis after quality assessment. After pooling 67 studies on post-TAVR PPMI risk in 97,294 patients, balloon-expandable valve use was negatively correlated with PPMI risk compared with self-expandable valve (SEV) use (odds ratio [OR]: 0.44, 95% confidence interval [CI]: 0.37-0.53). Meta-regression analysis revealed that history of coronary artery bypass grafting and higher Society of Thoracic Surgeons (STS) risk score increased the risk of PPMI with SEV utilization. Patients with pre-existing cardiac conduction abnormalities in 28 pooled studies also had a higher risk of PPMI(OR: 2.33, 95% CI: 1.90-2.86). Right bundle branch block (OR: 5.2, 95% CI: 4.37-6.18) and first-degree atrioventricular block (OR: 1.97, 95% CI: 1.38-2.79) also increased PPMI risk. Although the trans-femoral approach was positively correlated with PPMI risk, the trans-apical pathway showed no statistical difference to the trans-femoral pathway. The approach did not increase PPMI risk in patients with STS scores >8. Patient-prosthesis mismatch did not influence post-TAVR PPMI risk (OR: 0.88, 95% CI: 0.67-1.16). We also analyzed implantation depth and found no difference between patients with PPMI after TAVR and those without. SEV selection, pre-existing cardiac conduction abnormality, and trans-femoral pathway selection are positively correlated with PPMI after TAVR. Pre-existing left bundle branch block, patient-prosthesis mismatch, and implantation depth did not affect the risk of PPMI after TAVR.

Identifying predictive risk factors for permanent pacemaker implantation up to 30 days post-TAVI

Abstract Background Conduction system abnormalities, including AV block, are amongst the most common complications of transcatheter aortic valve implantation (TAVI). Post-TAVI high degree AV block necessitates permanent pacemaker (PPM) implantation. Purpose To assess the ability of standardly available pre-, intra- and post-TAVI factors to predict PPM implantation within 30-days post procedure. Methods Demographic and clinical (pre-, intra-, and post-procedural) data including ECG parameters were collected from all patients who underwent TAVI at our centre from August 2017 to November 2020. Patients with pre-existing PPM were excluded from the study. Predictive factors were selected through univariate analysis, and selected characteristics were incorporated into a multivariate binomial logistic regression model, in order to create a 30-day PPM risk-prediction model. The Akaike information criterion (AIC) and area under receiver operating curve (AUC/C-statistic) were used to assess discriminative performance. Results In total, data from a total of 446 patients were analysed. Of these, 40 (8.97%) received PPM implantation within 30 days of the procedure. The mean age of the patients was 81.5 (±7.3 SD) years; 99 (22.2%) had pre-existing first degree AV block, 55 (12.3%) had pre-existing left bundle branch block (LBBB) and 50 (11.2%) had pre-existing right bundle branch block (RBBB). Intra-procedurally 40 (9.0%) developed LBBB, 21 (4.7%) developed 3rd degree AV block, and 95 (21.3%) patients required temporary pacing wire (TPW) pacing. Post-procedurally, 138 (30.9%) exhibited AV block, 107 (24.0%) LBBB and 50 (11.2%) RBBB. The following factors met significance at multivariate logistic regression analysis: pre-TAVI RBBB (OR 6.62 [95% CI, 1.37–36.51]), intra-TAVI 3rd degree AV block (OR 12.80 [95% CI, 3.44–53.34]), intra-TAVI LBBB (OR 4.02 [95% CI, 1.28–12.53]), use of TPW pacing (OR 8.58 [95% CI, 3.19–25.12]) and post-TAVI LBBB (OR 7.84 [95% CI, 2.75–24.46]) (Table). Finally, variables were incorporated into a multivariate logistic regression model with the outcome variable of 30-day PPM implantation (Figure 1a). A model incorporating five factors (pre-TAVI RBBB, intra-TAVI 3rd degree AV block, intra-TAVI LBBB, use of TPW pacing and post-TAVI LBBB) demonstrated excellent discriminative ability (accuracy 0.925 and an AUC of 0.952) at predicting PPM implantation (Figure 1b). Conclusions Following variable selection, the best performing model incorporated five factors including pre-TAVI RBBB, intra-TAVI AV block (3rd degree), intra-TAVI LBBB, use of TPW pacing and post-TAVI LBBB. We aim to validate this model using an external cohort. Funding Acknowledgement Type of funding sources: None. Table 1Figure 1

Impact of new-onset left bundle branch block on clinical and echocardiographic outcomes after TAVR with SAPIEN-3 valve

Abstract Background New left bundle branch block (LBBB) is a common finding after transcatheter aortic valve replacement (TAVR) that can result in worse outcomes after TAVR. We aim to investigate the impact of new-onset LBBB after TAVR using the SAPIEN-3 (S3) valve. Methods Consecutive patients who underwent transfemoral-TAVR with S3 valve between April 2015 and December 2018 were included. Exclusion criteria included pre-existing LBBB, right bundle branch block, left anterior hemiblock, left posterior hemiblock, wide QRS ≥120 msec, prior permanent pacemaker (PPM), and non-transfemoral access. Results Among 612 patients, 11.4% developed new-onset LBBB upon discharge. Implantation depth was the only predictor of new-onset LBBB (OR 1.294; 95% CI 1.121–1.493; p&amp;lt;0.001). The median (IQR) length of stay was longer with new-onset LBBB [3 (2–5) days vs. 2 (1–3) days; p&amp;lt;0.001]. New-onset LBBB was associated with higher thirty-day PPM requirement (18.6% vs. 5.4%; p&amp;lt;0.001) including those implanted after discharge (4.3% vs. 0.9%; p=0.02). There was no difference in 3-year all-cause mortality between both groups (30.9% vs. 30.6%; log-rank p=0.829). Further, new-onset LBBB was associated with lower left ventricular ejection fraction (LVEF) at both 30 days (55.9±11.4% vs. 59.3±9%; p=0.026) and 1 year (55±12% vs. 60.1±8.9%; p=0.002) despite no differences at baseline. These changes were still present when we stratified patients according to baseline LVEF (≥50% or &amp;lt;50%). We also noted higher mean LV end-diastolic volume index (51.4±18.6 vs. 46.4±15.1 ml/m2; p=0.036), and LV end-systolic volume index (23.2±14.1 vs. 18.9±9.7 ml/m2; p=0.009) with new-onset LBBB at 1 year. Lastly, there were significantly higher rates of heart failure readmissions at 1 year with new-onset LBBB (10.7% vs. 4.4%; log-rank p=0.033). Conclusion Among our cohort of S3 recipients, new-onset LBBB was associated with higher PPM requirement, worse LVEF, higher LV volumes and increased risk of heart failure hospitalizations. However, it did not affect mortality in the short-to-intermediate post-TAVR period. Funding Acknowledgement Type of funding sources: None. Figure 1. All-cause Survival

Delayed occurrence of an accelerated idioventricular rhythm with alternating bundle branch block after myocardial infarction as predictor of sudden cardiac arrest: a case report.

BackgroundAccelerated idioventricular rhythm (AIVR) is known as reperfusion arrhythmia in the setting of acute myocardial infarction (AMI). In healthy individuals, it is usually considered to be benign. Alternating bundle branch block (ABBB) often progresses to complete atrioventricular block requiring permanent pacemaker implantation. We report a case of delayed appearance of AIVR following myocardial infarction (MI) in combination with ABBB as precursor of sudden cardiac arrest due to ventricular fibrillation (VF).Case summaryA 62-year-old male with pre-existing left bundle branch block (LBBB) was admitted with an acute non-ST segment elevation MI. He underwent successful percutaneous coronary intervention (PCI) of a subtotal proximal left anterior descending artery (LAD) stenosis. Before and after PCI the electrocardiogram (ECG) demonstrated sinus rhythm with LBBB. The patient was discharged 5 days after PCI, left ventricular function at this time was moderately reduced (ejection fraction of 40%). After another 5 days, the patient was admitted for elective cardiac rehabilitation. At this time, the ECG demonstrated an AIVR with right bundle branch block morphology. Due to ABBB, the patient was scheduled for permanent pacemaker implantation. Before pacemaker implantation could take place, the patient developed a sudden cardiac arrest due to VF and was successfully resuscitated. A follow-up coronary angiography revealed no novel lesions. A cardiac resynchronization therapy defibrillator was implanted for secondary prevention of sudden cardiac death.DiscussionDelayed occurrence of AIVR in combination with ABBB following AMI could be a predictor of sudden cardiac death. These patients are probably at high risk for malignant ventricular arrhythmias.