Background: Conduction disturbances demanding permanent pacemaker implantation (PPI) remains a common complication of transcatheter aortic valve replacement (TAVR), especially when a Boston Lotus valve has been applied. This is mainly due to the anchoring mechanism of most transcatheter heart valves (radial force) and the proximity of the implantation site to the cardiac conduction system. In TAVR procedure using an Evolut valve prosthesis, the novel cusp-overlap projection (COP) technique lowered the risk of interaction with the conduction system and was associated with reduced risk of PPI.

Objectives: The aim of this study was to determine if the application of the COP technique for TAVR with the repositionable Boston Lotus valve representing a TAVR prosthesis with the highest post-procedural PPI rates results in reduced incidence of new conduction disturbances.

Methods: In this prospective case-control study consecutive patients undergoing TAVR with the repositionable Boston Lotus valve using either conventional three-cusp coplanar (TCC) projection technique or COP view for implantation were included from March 2019 to December 2020. Incidence of post procedure PPI and left bundle branch block were compared between the two implantation techniques. Implantation depth (ID) was measured using postprocedural angiography.

Results: A total of 306 patients undergoing TAVR procedure with Boston Lotus heart valve were included in this analysis. Of those, 139 (45.4%) underwent TAVR using COP, whereas in 167 (54.6%) TCC technique was applied. Main baseline characteristics including mean age (81.2 years vs. 80.5 years; P=0.609), STS-score (3.0 vs. 3.2; P=0.402), prior left and right bundle branch block (10.5% vs. 12.0%; P=0.650 and 12.2 vs. 8.9%; P=0.332) or atrial fibrillation (21.7% vs. 19.2%; P=0.994) were equally distributed in both groups. A similar ID demonstrates that the final platform position did not differ significantly between both implantation techniques (mean difference -0.1 mm, 95%-CI -1.1 to +0.9 mm; P=0.890). Post-procedure, the novel COP technique was associated with a significant reduced incidence of left bundle branch block (28.1% vs. 47.9%; P<0.001) compared to the conventional TCC technique. PPI rates were 21.6% in the COP group and 25.7% in the TCC group (P=0.396).

Conclusion: The cusp overlap view facilitate the correct implantation of the repositionable Boston Lotus TAVR prosthesis and leads to less LVOT interference and reduced conduction disturbances compared to the standard TCC technique resulting in a significant lower rate of left bundle branch block.