Left Bundle Branch Block Before Transcatheter Aortic Valve Replacement

HomeCirculation: Cardiovascular InterventionsVol. 11, No. 11Left Bundle Branch Block Before Transcatheter Aortic Valve Replacement Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBLeft Bundle Branch Block Before Transcatheter Aortic Valve ReplacementIs There a Risk? Rajiv Gulati, MD, PhD and Andrew Wang, MD Rajiv GulatiRajiv Gulati Rajiv Gulati, MD, PhD, Department of Medicine, Mayo Clinic, 200 First St SW, Rochester, MN 55905. Email E-mail Address: [email protected] Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN (R.G.). and Andrew WangAndrew Wang Division of Cardiology, Duke University School of Medicine, Durham, NC (A.W.). Originally published19 Nov 2018https://doi.org/10.1161/CIRCINTERVENTIONS.118.007361Circulation: Cardiovascular Interventions. 2018;11:e007361This article is a commentary on the followingImpact of Preexisting Left Bundle Branch Block in Transcatheter Aortic Valve Replacement RecipientsSee Article by FischerTranscatheter aortic valve replacement (TAVR) has become a widely used therapy for patients with symptomatic severe aortic stenosis considered to be at intermediate, high, or prohibitive risk for surgery. Operator experience and technological iterations have led to a substantial reduction in the incidence of most TAVR procedural complications. However, the risk of conduction disturbances induced by TAVR requiring permanent pacemaker implantation (PPI) has not declined. Comprising about 13% of all TAVR procedures, need for PPI remains the commonest complication in contemporary practice.1The presence of right bundle branch block (BBB) before TAVR is the strongest predictor of development of high-grade atrioventricular block and need for PPI. This is because compression from the TAVR prosthesis on the membranous septum and interleaflet triangle between the right and noncoronary cusps threatens mechanical insult to the closely approximated left bundle branch, thereby risking a compounding of the baseline conduction deficit. Even with normal preprocedural conduction, new onset left BBB (LBBB) induced by TAVR may herald higher grade atrioventricular block via this mechanism and confers a 2-fold increased risk for early PPI.2What about patients with preexisting LBBB, who account for about 10% of the population undergoing TAVR? In this issue of the journal, Fischer et al3 address the less well understood impact of this particular baseline conduction abnormality on clinical outcomes after TAVR. The investigators performed a multicenter study of 4513 patients undergoing TAVR over a 12 year period. They excluded those with preexisting right BBB or prior PPI, leaving a cohort of 3404 for analysis. Among these, preexisting LBBB was present in 398 patients (11.7%). Follow-up was undertaken at 1 month, 1 year, and yearly thereafter (mean follow-up 22±21 months). Although patients with LBBB were older, with higher STS score and lower left ventricular ejection fraction (LVEF), all-cause and cardiovascular mortality at 30 days were no different compared with those without LBBB. Preexisting LBBB was, however, associated with a significantly increased risk of PPI by 30 days (21.1% versus 14.8%; P=0.006). Notably, there was no increased risk of PPI beyond 30 days in a subanalysis of 2421 patients.The early—but not late—hazard for PPI in those with preexisting LBBB is consistent with but not conclusive of a mechanical explanation. While TAVR placement is more likely in general to impact conduction through the left bundle branch given anatomic localization, deeper valve implantation abutting the inferior membranous septum may also injure the right bundle branch. Implant depth was not evaluated in this study but would be of interest to understand whether this direct mechanical effect could explain the increased rates of early PPI in those with preexisting LBBB. Given the higher rate of PPI with self-expandable TAVR devices, which may have delayed expansion after implantation, this procedural consideration may be a modifiable factor for future study. An alternate explanation could be bias in selection of patients for PPI after TAVR, that is, the presence of a broad QRS conduction pattern at baseline might have lowered the threshold for clinicians to recommend PPI after TAVR because of a heightened concern that may, for example, relate to knowledge of prior intermittent conduction defects or may simply be nonspecific and hard to define. This aspect, of course, cannot be addressed in studies such as this where triggers for PPI, such as specific conduction disturbances were not prespecified. In the MARE study of patients who develop new LBBB after TAVR, PPI was performed as often for bradycardia as high degree atrioventricular block.3The study by Fischer et al4 also demonstrated that despite the lower initial LVEF in the group with preexisting LBBB, both groups experienced a similar degree of increase in LVEF at 1-year follow-up (Δ+2.9±0.7% versus Δ+1.4±0.2%). Similarly, LVEF improved in the subset of those with LVEF <50% at baseline regardless of baseline conduction. These findings contrast with those of numerous natural history studies of patients with LBBB but without aortic stenosis, where LBBB is nearly always associated with higher risk of adverse outcomes. Fischer et al4 suggest reasonably that the lack of hazard seen in their study may relate to the highly beneficial impact of the treatment aortic stenosis treatment. However, the relatively shorter duration of follow-up is a key difference and whether preexisting LBBB in those who receive TAVR might impact long-term outcomes remains to be seen.In patients with preexisting LBBB, additional electrocardiographic findings, such as QRS duration, may define a subgroup of patients who are at increased risk of PPI, either in the postprocedure or longer-term period. Similarly, interrogation of PPI devices after implantation could identify those patients who do have a high burden of ventricular pacing as opposed to atrial pacing for sinus node dysfunction. In patients with preexisting LBBB and reduced LVEF after TAVR, a consideration for PPI may be the potential benefit of cardiac resynchronization and implantable cardioverter-defibrillator therapy, although this would be applicable several months after TAVR.Should the findings of the study by Fischer et al4 affect clinical practice? Certainly, it seems reasonable to incorporate their observation of elevated early PPI risk when counseling patients with LBBB before TAVR. The findings also support a rationale for avoiding low implant depth where possible and may favor a selection of valve type with lower PPI risk. The current study findings can provide reassurance for no late hazard for PPI, mortality, or LVEF worsening compared with those without pre-TAVR LBBB. However, the observational nature of the study and specifically the lack of knowledge of whether new high-grade atrioventricular block underpinned the increased rate of PPI means suggest that additional studies are needed before incorporating pre-TAVR LBBB into a PPI decision algorithm.It perhaps remains surprising in the current era how little we understand about progression—or regression—of electrical conduction disturbance in the weeks following TAVR. This uncertainty likely explains the wide variation in utilization of PPI across TAVR sites. The study by Fischer et al4 should provide further impetus for systematic studies of prolonged ECG monitoring after TAVR. Given the trajectory of TAVR utilization worldwide and corresponding burden of PPI, even studies of limited sample size in patients with baseline conduction abnormalities that employ routine monitoring for a period of weeks abnormalities could have profound clinical and economic impact.DisclosuresNone.FootnotesThe opinions expressed in this editorial are not necessarily those of the editors or of the American Heart Association.Rajiv Gulati, MD, PhD, Department of Medicine, Mayo Clinic, 200 First St SW, Rochester, MN 55905. Email gulati.[email protected]eduReferences1. Auffret V, Puri R, Urena M, Chamandi C, Rodriguez-Gabella T, Philippon F, Rodés-Cabau J. Conduction disturbances after transcatheter aortic valve replacement: current status and future perspectives.Circulation. 2017; 136:1049–1069. doi: 10.1161/CIRCULATIONAHA.117.028352LinkGoogle Scholar2. Regueiro A, Abdul-Jawad Altisent O, Del Trigo M, Campelo-Parada F, Puri R, Urena M, Philippon F, Rodés-Cabau J. Impact of new-onset left bundle branch block and periprocedural permanent pacemaker implantation on clinical outcomes in patients undergoing transcatheter aortic valve replacement: a systematic review and meta- analysis.Circ Cardiovasc Interv. 2016; 9:e003635. doi: 10.1161/CIRCINTERVENTIONS.115.003635LinkGoogle Scholar3. Rodés-Cabau J, Urena M, Nombela-Franco L, Amat-Santos I, Kleiman N, Munoz-Garcia A, Atienza F, Serra V, Deyell MW, Veiga-Fernandez G, Masson JB, Canadas-Godoy V, Himbert D, Castrodeza J, Elizaga J, Francisco Pascual J, Webb JG, de la Torre JM, Asmarats L, Pelletier-Beaumont E, Philippon F. Arrhythmic burden as determined by ambulatory continuous cardiac monitoring in patients with new-onset persistent left bundle branch block following transcatheter aortic valve replacement: the MARE study.JACC Cardiovasc Interv. 2018; 11:1495–1505.CrossrefMedlineGoogle Scholar4. Fischer Q, Himbert D, Webb JG, Eltchaninoff H, Muñoz-García AJ, Tamburino C, Nombela-Franco L, Nietlispach F, Moris C, Ruel M, Dager AE, Serra V, Cheema A, Amat-Santos IJ, de Brito FS, Ribeiro H, Abizaid A, Sarmento-Leite R, Dumont E, Barbanti M, Durand E, Alonso Briales JH, Bouleti C, Imme S, Masiano F, del Valle R, Miguel Benitez L,Garcia del Blanco B, Cote M, Philippon F, Urena M, Rodés-Cabau J. Impact of preexisting left bundle branch block in transcatheter aortic valve replacement recipients.Circ Cardiovasc Interv. 2018: 11;e006927. doi: 10.1161/CIRCINTERVENTIONS.118.006927LinkGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Sammour Y, Sato K, Kumar A, Gajulapalli R, Lak H, Chawla S, Banerjee K, Kaur M, Patel J, Incognito C, Svensson L, Popovic Z, Tarakji K, Wazni O, Reed G, Yun J, Puri R, Krishnaswamy A and Kapadia S (2020) Impact of baseline conduction abnormalities on outcomes after transcatheter aortic valve replacement with SAPIEN ‐3 , Catheterization and Cardiovascular Interventions, 10.1002/ccd.29309, 98:1, Online publication date: 1-Jul-2021. Sammour Y, Krishnaswamy A, Kumar A, Puri R, Tarakji K, Bazarbashi N, Harb S, Griffin B, Svensson L, Wazni O and Kapadia S (2021) Incidence, Predictors, and Implications of Permanent Pacemaker Requirement After Transcatheter Aortic Valve Replacement, JACC: Cardiovascular Interventions, 10.1016/j.jcin.2020.09.063, 14:2, (115-134), Online publication date: 1-Jan-2021. Reiter C, Lambert T, Kellermair J, Blessberger H, Fellner A, Nahler A, Grund M and Steinwender C (2021) Delayed Total Atrioventricular Block After Transcatheter Aortic Valve Replacement Assessed by Implantable Loop Recorders, JACC: Cardiovascular Interventions, 10.1016/j.jcin.2021.09.003, 14:24, (2723-2732), Online publication date: 1-Dec-2021. Related articlesImpact of Preexisting Left Bundle Branch Block in Transcatheter Aortic Valve Replacement RecipientsQuentin Fischer, et al. Circulation: Cardiovascular Interventions. 2018;11 November 2018Vol 11, Issue 11 Advertisement Article InformationMetrics © 2018 American Heart Association, Inc.https://doi.org/10.1161/CIRCINTERVENTIONS.118.007361PMID: 30571212 Originally publishedNovember 19, 2018 Keywordsatrioventricular blockEditorialstranscatheter aortic valve replacementmortalityincidencebundle branch blockPDF download Advertisement SubjectsSudden Cardiac DeathValvular Heart Disease