Transcatheter aortic valve replacement (TAVR) is a well-established alternative to surgery for the treatment of patients with severe symptomatic aortic stenosis at increased surgical risk. The occurrence of electrical conduction disturbances with new-onset left bundle branch block (LBBB) or the need for permanent pacemaker (PPM) implantation remains one of the most frequent adverse events of the procedure with possible impact on prognosis.

 

We performed a meta-analysis to summarize available studies that reported the incidence of new PPM and new LBBB after TAVR and investigated the rate and possible predictors of recovery from these conduction disturbances during follow-up.

 

The authors conducted a literature search in PubMed and MEDLINE databases from January 2012 to October 2022. 24 observational studies (n=14244) met inclusion criteria for the final analysis with 19 studies reporting about new PPM (n=11350) and 6 studies dealing with new LBBB (n=2894) following TAVR.

 

Results: 

PPM implantation was performed in 1742 patients following TAVR (15.3%), mostly due to complete atrioventricular heart block (72.6%). New-onset LBBB occurred in 664 patients after TAVR (22.9%). A follow-up of 1671 patients was performed after a median period of 224 days. 45.7% of the patients with completed follow-up (n=764) showed recovery from PPM dependency (n=493; 48.4%) or spontaneous resolution of LBBB (n=271; 41.5%). Regarding secondary endpoints’ analysis of relative risk (RR) and mean difference (MD) during follow-up, patient-related factors associated with PPM dependency and LBBB persistence were male sex (RR 1.20; 95% CI 1.07-1.36; p=0.003) and pre-existing diabetes mellitus (RR 1.18; 95% CI 1.02-1.38; p=0.03). Electrocardiographic predictors for long-term PPM dependency and LBBB persistence after TAVR appeared to be prolonged QRS duration before TAVR (MD 4.92 ms; 95% CI 2.23-7.61 ms; p<0.001) and prior atrial fibrillation (RR 1.26; 95% CI 1.04-1.52; p=0.02). Pre-existing right bundle branch block (RBBB) was highly predictive for persistent PPM dependency following TAVR (RR 1.84; 95% CI 1.45-2.35; p<0.001). 

Procedural predictors of persistent conduction defects were higher calcium volume of the aortic valve (MD 143.7 mm3; 95% CI 31.2-370.8 mm3; p=0.01), larger aortic annulus diameter (MD 0.98 mm; 95% CI 0.33-1.63 mm; p=0.003), and accordingly, implantation of larger prosthetic valves with sizes ranging from 29 to 34 mm (RR 1.53; 95% CI 1.21-1.94; p<0.001). While greater implantation depth was predictive for persistence of conduction disorders (MD 0.75 mm; 95% CI 0.28-1.22 mm; p=0.002), the use of balloon-expandable bio-prostheses showed significantly higher rates of recovery (RR 1.16; 95% CI 1.00-1.34; p=0.04).

Patients with recovery of PPM dependency during follow-up showed more indications other than complete heart block for PPM implantation (RR 2.46; 95% CI 1.78-3.39; p<0.001). Especially a new-onset LBBB with subsequent PPM dependency over time turned out to be a strong predictor of PPM recovery (RR 2.09; 95% CI 1.36-3.20; p<0.001).

 

This structured meta-analysis proved new PPM implantation in 15.3% and new LBBB in 22.9% of patients following TAVR with almost half of the cases (45.7%) recovering spontaneously during follow-up. Therefore, a prolonged monitoring of patients with new-onset conduction disturbances should be considered, rather than immediate PPM implantation after TAVR.