Background

Pre-existing right bundle branch block (RBBB) has consistently shown to be the strongest patient-related predictor for new permanent pacemaker implantation (PPI) after transcatheter aortic valve replacement (TAVR) with an up to 12-fold risk increase resulting in elevated PPI rates of up to 40%. No comparison of newer generation transcatheter heart valves (THV) with regard to PPI in these patients exists. The aim of this study was to evaluate the impact of ACURATE neo (NEO) versus SAPIEN 3 (S3) on PPI in patients with RBBB.

Methods

The SELECT RBBB registry includes consecutive patients undergoing TAVR using the NEO or the S3 for severe symptomatic aortic stenosis in 7 centers in Germany and Switzerland between January 2014 and July 2017. Of 4305 patients, 302 fulfilled the inclusion criteria consisting of pre-existent complete RBBB and no pacemaker at baseline. Of these, 6 patients with incomplete multi-slice CT data were excluded, resulting in a study population of 296 patients. The primary endpoint was new PPI before discharge. The association of NEO vs. S3 with PPI was assessed using binary logistic regression analyses, inverse probability treatment weighting (IPTW) and in a propensity matched population (figure 1 left panel).

Results

The overall PPI rate was 37.8%. The S3 and NEO were used in 66.9% and 33.1%, respectively. Use of NEO was associated with a lower rate of PPI compared to S3 (29.8% vs. 41.9%, p=0.040, odds ratio (OR) 0.58 95% confidence interval (CI) [0.34-0.97], p=0.041), after multivariable adjustment (OR 0.50 95%CI [0.28-0.90], p=0.022) and in the IPTW analysis (OR 0.38 95%CI [0.25-0.56], p<0.001, figure 1 right panel). Regarding device failure, there was no difference between NEO and S3 (8.2% vs. 6.2%, p=0.792). Postprocedural mean transaortic gradients were significantly lower with NEO (8 mmHg vs. 11, p<0.001). In-hospital complications were comparable between the two THV.
Results from the entire population analysis were confirmed in the propensity matched population in which PPI rate was also lower with NEO vs. S3 (23.1% vs. 49.2%, p=0.001, OR 0.31 95% CI [0.14-0.65], p=0.002, figure 1 right panel), while there was no difference in rate and risk of device failure (9.2% vs. 6.2%, p=0.742, OR 1.55 [0.42-6.33], p=0.513).

Conclusions

As the identification of patients with pre-existent RBBB is easily performed via baseline ECG, the present SELECT RBBB registry suggests the possibility of a patient-tailored THV therapy to reduce PPI rate after TAVR in this subset of patients at high risk for conduction disturbances.

Figure 1 - Study flow (left panel) and risk for permanent pacemaker implantation according to ACURATE neo or SAPIEN 3 (right panel)