Conductive disturbances in the transcatheter aortic valve implantation setting: An appraisal of current knowledge and unmet needs

New-onset conduction disturbances, including left bundle branch block and permanent pacemaker implantation, remain a major issue after transcatheter aortic valve implantation. Preprocedural risk assessment in current practice is most often limited to evaluation of the baseline electrocardiogram, whereas it may benefit from a multimodal approach, including ambulatory electrocardiogram monitoring and multidetector computed tomography. Physicians may encounter equivocal situations during the hospital phase, and the management of follow-up is not fully defined, despite the publication of several expert consensuses and the inclusion of recommendations regarding the role of electrophysiology studies and postprocedural monitoring in recent guidelines. This review provides an overview of current knowledge and future perspectives regarding the management of new-onset conduction disturbances in the setting of transcatheter aortic valve implantation, from the preprocedural phase to long-term follow-up.

Preprocedural and procedural variables that predict new-onset conduction disturbances after transcatheter aortic valve replacement

Background

Conduction disturbances are a common complication after transcatheter aortic valve replacement (TAVR). The aim of this study was to investigate the preprocedural and procedural variables that predict new-onset conduction disturbances post-TAVR (hereafter CD/CDs).

Methods

Consecutive patients who underwent TAVR during December 2009–March 2021 at the Faculty of Medicine Siriraj Hospital, Mahidol University—Thailand’s largest national tertiary referral center—were enrolled. Patients with prior implantation of a cardiac device, periprocedural death, or unsuccessful procedure were excluded. Clinical and electrocardiographic data, preprocedural imaging, including membranous septum (MS) length, and procedural variables, including implantation depth (ID), were analyzed. CD was defined as new left or right bundle branch block, significant intraventricular conduction disturbance with QRS interval ≥ 120 ms, new high-grade atrioventricular block, or complete heart block. Multivariate binary logistic analysis and receiver operating characteristic (ROC) curve analysis were used to identify independent predictors and the optimal ∆MSID (difference between the MS length and ID) cutoff value, respectively.

Results

A total of 124 TAVR patients (mean age: 84.3 ± 6.3 years, 62.1% female) were included. The mean Society of Thoracic Surgeons score was 7.3%, and 85% of patients received a balloon expandable transcatheter heart valve. Thirty-five patients (28.2%) experienced a CD, and one-third of those required pacemaker implantation. The significant preprocedural and procedural factors identified from univariate analysis included intraventricular conduction delay, mitral annular calcification, MS length ≤ 6.43 mm, self-expanding device, small left ventricular cavity, and ID ≥ 6 mm. Multivariate analysis revealed MS length ≤ 6.43 mm (adjusted odds ratio [aOR] 9.54; 95% CI 2.56–35.47; p = 0.001) and ∆MSID < 0 mm (adjusted odds ratio [aOR] 10.77; 95% CI 2.86–40.62; p =  < 0.001) to be independent predictors of CD. The optimal ∆MSID cutoff value for predicting conduction disturbances was less than 0 mm (area under the receiver operating characteristic curve [AuROC]: 0.896).

Conclusion

This study identified MS length ≤ 6.43 mm and ∆MSID < 0 mm as independent predictors of CDs. ∆MSID < 0 was the strongest and only modifiable predictor. Importantly, we expanded the CD criteria to cover all spectrum of TAVR-related conduction injury to lower the threshold of this sole modifiable risk. The optimal ∆MSID cutoff value was < 0 mm.

Trial registration: TCTR, TCTR20210818002. Registered 17 August 2021—Retrospectively registered, http://www.thaiclinicaltrials.org/show/TCTR 20210818002.