Prosthesis depth and conduction disturbances after last generation balloon-expandable transcatheter aortic valve implantation

Aims: Preliminary data on Sapien 3 valve (S3-THV) use for transcatheter aortic valve implantation have shown an increased permanent pacemaker implantation (PPMI) rate with respect to Sapien XT valve. Aim of this study was to investigate the role of S3-THV position in the left ventricular outflow tract (LVOT) on electrocardiographic changes suggestive of atrioventricular (ΔPR) and/or intraventricular (ΔQRS) conduction abnormalities and 30 days PPMI rate. Methods and results: Eighty-six consecutive patients treated with S3-THV were included in the study. All patients underwent clinical and electrocardiogram evaluation. Left ventricular outflow tract prosthesis depth was assessed by fluoroscopy and expressed quantitatively (mm) and as aorto-ventricular ratio (AVR). Eight patients (9.3%) needed PPMI at 30 days. A low AVR (≤60/40) predicted PPMI (OR = 6.09, 95% CI 1.19-31.01, P = 0.030) and resulted into higher PPMI rate, compared with higher AVR (30.0 vs. 6.6%, P = 0.017). For each millimetre increase in the LVOT prosthesis depth PPMI risk increased by 1.41 times (95% CI 1.06-1.87, P = 0.017). In patients with low AVR, ΔPR was higher than in those with higher AVR (33.4 ± 56.7 vs. 12.1 ± 19.4 ms, P = 0.021) and ΔPR was associated to LVOT prosthesis depth (β = 0.286, P = 0.009). Furthermore, ΔPR was associated with risk of PPMI (OR = 1.03, 95% CI 1.01-1.06, P = 0.024). Conclusions: A low AVR is associated to higher ΔPR and PPMI rates. The correlation between LVOT prosthesis depth with ΔPR and higher PPMI rate suggests the need of a careful S3-THV implantation.