QRS duration, left bundle branch block morphology, and outcomes among patients who undergo septal myectomy.

Usefulness of Echocardiographically Guided Left Ventricular Lead Placement for Cardiac Resynchronization Therapy in Patients With Intermediate QRS Width and Non–Left Bundle Branch Block Morphology

Impact of postoperative left bundle branch block on left ventricular remodeling following transapical beating-heart septal myectomy.

Does cardiac resynchronization therapy benefit patients with right bundle branch block: cardiac resynchronization therapy has a role in patients with right bundle branch block.

POSTER PRESENTATIONS

HOW MANY PATIENTS HOSPITALIZED WITH HEART FAILURE ARE ELIGIBLE FOR CARDIAC RESYNCHRONIZATION THERAPY ACCORDING TO UPDATED GUIDELINES?

Developed in Collaboration With the American Association for Thoracic Surgery, Heart Failure Society of America, and Society of Thoracic Surgeons

Predictive Factors and Long-Term Clinical Consequences of Persistent Left Bundle Branch Block Following Transcatheter Aortic Valve Implantation With a Balloon-Expandable Valve

His bundle pacing improves left ventricular diastolic function in patients with heart failure with preserved systolic function

Early Resolution of New-Onset Left Bundle Branch Block After Transcatheter Aortic Valve Implantation With the SAPIEN 3 Valve

INTRODUCTION The electrocardiographic (ECG) pattern of true left bundle branch block (LBBB) has not been fully clarified and various definitions of LBBB exist. New-onset LBBB after transcatheter (TAVR) or surgical (SAVR) aortic valve replacement implies a proximal pathogenesis of LBBB and thus may provide a reference to characterize and define true LBBB. PURPOSE This study compares ECG characteristics in aortic valve implantation-induced LBBB (AVI-LBBB) to a non-procedural-induced LBBB control group (co-LBBB) in order to set a more homogenous definition for true LBBB. METHODS The study enrolled all patients with new-onset TAVR- and SAVR-induced LBBB between 2013 and 2019. AVI-LBBB was defined as new-onset persistent LBBB occurring within 24h after TAVR or SAVR. Patients were matched for age, sex, ischemic heart disease and left ventricular systolic function to randomly selected co-LBBB patients in a 1:2 ratio. For inclusion in both groups, a non-strict LBBB definition was used (QRSD ≥120ms, QS or rS in lead V1, absence of Q wave in leads V5-6). ECG characteristics were digitally analysed by the MUSE algorithm and confirmed by two experts. All ECG recordings were classified according to 4 different LBBB definitions: MADIT, European Society of Cardiology (ESC), Strauss and American Heart Association (AHA). RESULTS 59 patients with AVI-LBBB (34 TAVR, 25 SAVR, median age 82 years, 42% male) were compared to 118 matched co-LBBB patients. All patients with AVI-LBBB presented with QRS notching/slurring in the lateral leads, whereas this was present in only 85% of the co-LBBB group (p = 0.001). QRS duration (148ms vs 145ms, p = 0.074) and R wave peak time (58ms vs 62ms, p = 0.065) were not significantly different among both groups. AVI-LBBB was characterized by a more rightward QRS axis (-15° vs -30°, p = 0.013). When comparing AVI-LBBB to LBBB controls with QRS notching/slurring, a comparable QRS axis was observed. Almost all AVI-LBBB patients met the MADIT (98%), ESC (100%) and Strauss (95%) definition. Only 18% of patients met the AHA definition, because of the low combined presence of QRS notching/slurring in all 4 lateral leads (54%) and because only 27% of patients had an R wave peak time >60ms in both leads V5-6. In the co-LBBB group, adherence to the different definitions was significantly lower compared to the AVI-LBBB group: MADIT 86% (p = 0.007), ESC 85% (p = 0.001), Strauss 68% (p < 0.001) and AHA 7% (p = 0.035). Lower presence of lateral notching/slurring and more patients with smaller QRS duration (QRS duration ≥130ms, 86% vs 98%, p = 0.007) in the co-LBBB group explain these results. CONCLUSIONS Discordance exists between various definitions in scoring AVI-LBBB. Our data show that presence of QRS notching/slurring in the lateral leads is a crucial feature of proximal LBBB, rather than QRS duration and R wave peak time. The AVI-LBBB population provides a framework towards a more uniform definition and criteria for assessing true, proximal LBBB.

The combination of left bundle branch block (LBBB) morphology and QRS duration is currently used to select patients for cardiac resynchronization therapy (CRT). These parameters, however, have limitations. This study evaluates the value of QRS area compared with that of QRS duration and morphology in the association with clinical and echocardiographic outcomes in a large cohort of CRT patients. A retrospective multicentre study was conducted in 1492 CRT patients. LBBB morphology, QRS duration, and QRS area in the baseline 12-lead ECG were evaluated for their association with the occurrence of the combined primary end point of all-cause mortality, cardiac transplantation, and left ventricular assist device implantation. Secondary end points were heart failure hospitalization within the first year after implantation and echocardiographic reduction in left ventricular end-systolic volume. During a mean follow-up period of 3.4 years, 32% of patients reached the primary end point. The association of QRS area with all outcomes was stronger than that of LBBB morphology and QRS duration separately and at least as strong as their combination. QRS area identified patients who did not experience the primary end point better than QRS morphology and QRS duration (area under the curve, 0.61 versus 0.55 and 0.51, respectively; P<0.001). Furthermore, QRS area identifies patients with echocardiographic remodeling in response to CRT better than QRS morphology and duration (area under the curve, 0.69 versus 0.58 and 0.58, respectively; P<0.001). QRS area was the only independent electrocardiographic determinant associated with the primary end point; hazard ratio, 0.50 (0.35-0.71). Furthermore, QRS area showed significant association with outcomes in both patients with and without LBBB and QRS ≥150 ms. QRS area has a strong association to clinical and echocardiographic response to CRT, at least as strong as current patient selection parameters. QRS area may be particularly useful to predict CRT response in patients without a wide LBBB.

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

Background: The most common conduction abnormality after transcatheter aortic valve replacement (TAVR) is new-onset left bundle branch block (LBBB) with an exact frequency that varies based on the valve system used for TAVR. PPM implantation in patients with persistent new onset LBBB post TAVR is controversial. The primary objective of this study is to report PPM utilisation and mortality in this patient population.Methods: A TAVR registry included patients older than 18 years who underwent TAVR between March 2012 and June 2015 at University of Minnesota Medical Centre. After exclusion, 151 patients were divided into two groups; patients with persistent new onset LBBB after TAVR (new LBBB, n = 47) and patients without persistent new onset LBBB (no new LBBB, n = 104).Results: Among the 151 patients, 47 (31.1%) patients developed new-onset LBBB after the procedure and persisted at discharge. Left ventricular ejection fraction (LVEF) (52.5 ± 11.1 vs. 56.4 ± 10.8, p: .047) and mean aortic valve gradient (40.6 ± 11.5 vs. 45.7 ± 14.1, p: .022) were significantly higher in no new LBBB group. Among those with new LBBB, there was a significantly higher rate of PPM implant during index hospitalisation (14.9%, vs. 0%, p < .001). LVEF remained significantly lower at 1 year follow up in new LBBB group compared to no new LBBB group (51.8 ± 11.2 vs. 57.6 ± 8.3, p: .002). Also in new LBBB group, there was a non-significantly higher rate of all-cause mortality in 1 year compared to no new LBBB group (14.9% vs. 9.6% p: .34). There were no significant differences between patients with and without new LBBB with respect to PPM implant after discharge in 1 year (2.13% vs. 3.8% p: .58), length of stay (7.3 ± 7.3 vs. 5.9 ± 2.7 p: .09), post-op atrial fibrillation (AF) (16.3% vs. 8.5% p: .20).Conclusions: New onset LBBB was frequent conduction problem post TAVR and one-third of patients with new onset LBBB persisted at discharge. New LBBB after TAVR was associated with a higher risk of PPM implantation during the index hospitalisation but not after discharge. Our findings suggest that early PPM implantation for post-TAVR LBBB is not indicated without complete or high degree AV block. Further research is required to identify the patients with new LBBB who would progress to advanced AV block or heart failure.

Hemodynamic Impact and Outcome of Permanent Pacemaker Implantation Following 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 ± 7years, 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 6months 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 &lt;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 6months 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.