Impact of leaflet laceration on the occurrence of hypoattenuated leaflet thickening after valve-in-valve TAVI

J. Rotta Detto Loria (Leipzig)¹, A. Abdelhafez (Leipzig)¹, I. Richter (Leipzig)², N. Majunke (Leipzig)¹, H.-J. Feistritzer (Leipzig)¹, R. Gohmann (Leipzig)³, T. Noack (Leipzig)⁴, H. Thiele (Leipzig)¹, M. Abdel-Wahab (Leipzig)^1
1Herzzentrum Leipzig - Universität Leipzig Klinik für Innere Medizin/Kardiologie Leipzig, Deutschland; ²Helios Park-Klinikum Leipzig Klinik für Innere Medizin I - Kardiologie, Angiologie Leipzig, Deutschland; ³Herzzentrum Leipzig - Universität Leipzig Diagnostische und Interventionelle Radiologie Leipzig, Deutschland; ⁴Herzzentrum Leipzig - Universität Leipzig Universitätsklinik für Herzchirurgie Leipzig, Deutschland

Aims
Valve-in-valve TAVI has become an established procedure for patients with failed bioprosthetic aortic valves and increased risk for re-operation. Apart from coronary flow obstruction as a possible complication, valve-in-valve TAVI is associated with the increased occurrence of hypoattenuated leaflet thickening (HALT) potentially impairing valve hemodynamics. Electrosurgery with intentional leaflet laceration has proven successful in preventing coronary obstruction. In this study, we investigated the impact of leaflet laceration on the occurrence of HALT and other procedural outcomes.

Methods and results
A total of 113 consecutive patients undergoing valve-in-valve TAVI and a post-TAVI computed tomography (CT) examination at a single high-volume center between 2018 and 2024 were included in this observational study. Definition of HALT in the CT evaluation was adopted as described previously by Jilaihawi et al. Patients deemed high risk for coronary obstruction according to the local Heart Team underwent single or dual leaflet laceration using Bioprosthetic Aortic Scallop Intentional Laceration to prevent Iatrogenic Coronary Artery obstruction (BASILICA) technique.Fifty-eight patients (51.3%) were treated with valve-in-valve TAVI alone (non-BASILICA group) and 55 (48.7%) patients underwent additional BASILICA (BASILICA group). Patients in the BASILICA group were older (77±8 vs. 79±6 years; p=0.03) and more commonly women (non-BASILICA 24/58 [40%] vs. BASILICA 36/55 [60%]; p=0.01). LVEF at baseline did not differ significantly between the groups (non-BASILICA 55±15 vs. BASILICA 56±10%; p=0.43).Post-procedural transvalvular mean gradient was significantly higher in the non-BASILICA group (18.6±9.0 vs. 12.7±6.2 mmHg; p<0.001). There was no significant difference in the aortic valve area after the valve-in-valve procedure (non-BASILICA 1.4±0.4 vs. BASILICA 1.5±0.4 cm2; p=0.23).A total of 37/113 patients (32.7%) were diagnosed with HALT on post-procedural CT-imaging. HALT occurred significantly less in the BASILICA group (non-BASILICA 25/58 [43.1%] vs. BASILICA 12/55 [21.8%]; p=0.02). Patients with HALT had higher post-procedural transvalvular gradients (18.6±7.9 vs. 14.3±8.1 mmHg; p<0.004). The use of balloon-expandable transcatheter heart valves was associated with higher rates of HALT (no HALT 17.1% vs HALT 40.4%; p=0.01). In patients with BASILICA and HALT (n=12), leaflet thrombosis was mostly present in the non-lacerated cusp (HALT in lacerated cusp 3/12 [25%] vs. HALT in non-lacerated cusp 9/12 [75%]). HALT did not occur in patients with dual leaflet BASILICA (n=6).

Conclusions
The rate of HALT in patients undergoing valve-in-valve TAVI and concomitant BASILICA is significantly lower than without BASILICA. This may be a result of improved sinus and neo-sinus washout after leaflet laceration. Although this finding has been previously observed in in-silico and in-vitro models, it has never been reported from an in-vivo cohort so far. Ultimately, preventing HALT may be beneficial in terms of valve hemodynamics and durability.