Impact of Accidental High or Low Implantation Depth on Peri-Procedural Outcomes after Implantation with the Self-Expanding ACURATE neo2

<b>Background</b>: Precise implantation could play a crucial role in the technical success of transcatheter aortic valve replacement (TAVR) for some prostheses. The impact of an accidental implantation depth (ID) outside the recommended range has not been assessed for the ACURATE <i>neo2</i> (NEO2). <b>Methods</b>: Data from 1839 patients with severe native aortic stenosis treated with the NEO2 prosthesis were evaluated. We compared the results of prostheses implanted in an ID both inside and outside the recommendations. The outcome assessment followed the Valve Academic Research Consortium-3 criteria. <b>Results</b>: Patients were retrospectively divided into high (<3 mm; <i>n</i> = 412), optimal (3-7 mm; <i>n</i> = 1236), and low (>7 mm; <i>n</i> = 169) implantations. Technical success (94.7% vs. 94.7% vs. 91.7%, <i>p</i> = 0.296) and device success were high (90.1% vs. 89.3% vs. 84.6%, <i>p</i> = 0.112) without differences between groups. Rates of relevant paravalvular regurgitation (PVL; >mild or VinV due to PVL) were comparable (1.2% vs. 1.8% vs. 1.2%, <i>p</i> = 0.759). Even when hemodynamics were superior in the high-implantation group, with greater iEOA (1.01 cm²/m² vs. 0.95 cm²/m² vs. 0.92 cm²/m², <i>p</i> < 0.001), spontaneous embolization or after post-dilatation was more common. Low implantation was associated with a higher rate of associated pacemaker implantation (PPI) (6.1% vs. 8.8% vs. 14.8%, <i>p</i> = 0.001). <b>Conclusions</b>: Implantation with the ACURATE <i>neo2</i> showed excellent hemodynamic results, including low gradients and a small number of relevant PVL, in line with a high technical success rate that was irrespective of the ID. A favorable outcome can also be achieved in accidental low or high positions. Low implantation was associated with a higher rate of associated pacemaker implantation. Deliberately high implantation should be avoided due to the risk of embolization.