RESUMEN
Coronary obstruction (CO) is a potential pitfall for transcatheter aortic valve replacement (TAVR), especially in valve in valve procedures into degenerated surgical or transcatheter prostheses. Bioprosthetic leaflet modification techniques that incorporate electrosurgery are evolving as the preferred strategy to mitigate the risk of CO in high CO risk settings. The UNICORN method is proposed as a more predictable leaflet modification strategy than the earlier described BASILICA approach, but its proponents have hitherto mandated the use of a balloon-expandable valve (BEV) prosthesis. Many patients have small prostheses and therein face a significant risk of patient prosthesis mismatch with BEV in this setting. This risk may be curtailed if a self-expanding valve (SEV) prosthesis could be used. Herein described is a modified approach to allow for the utilization of SEV systems in this setting.
RESUMEN
Aims: Dynamic left ventricular (LV) outflow tract obstruction (LVOTO) is associated with symptoms and increased risk of developing heart failure in hypertrophic cardiomyopathy (HCM). The association of LVOTO and LV twist mechanics has not been well studied in HCM. The aim of the study was to compare the pattern of LV twist in patients with HCM associated with asymmetrical septal hypertrophy with and without LVOTO. Methods and results: Echocardiography (including speckle tracking) was performed in 212 patients with HCM, divided according to the absence (n = 130) or presence (n = 82) of LVOTO (defined as peak pressure gradient ≥30â mmHg either at rest and/or with Valsalva manoeuvre). Patients with LVOTO were older, had smaller LV dimensions, a higher LV ejection fraction (LVEF), a longer anterior mitral valve leaflet length, and a higher early transmitral pulsed wave to septal tissue Doppler velocity ratio (E/E'). A univariate analysis showed that peak twist was significantly higher in patients with LVOTO compared with patients without LVOTO (19.7 ± 7.3 vs. 15.7 ± 6.0, P = 0.00015). Peak twist was similarly enhanced in patients with LVOTO, manifesting only during Valsalva (19.2 ± 5.6, P = 0.007) and patients with resting LVOTO (19.9 ± 8.0, P = 0.00004) compared with patients without LVOTO (15.7 ± 6.0). A stepwise forward logistic regression analysis showed that LVEF, LV end-systolic dimension indexed to body surface area, anterior mitral valve leaflet length, E/E', and peak twist were all independently associated with LVOTO. Conclusion: This study demonstrates that increased peak LV twist is independently associated with LVOTO in patients with HCM. Peak twist was similarly exaggerated in patients with only latent LVOTO, suggesting that it may play a contributory role to LVOTO in HCM.