Transcatheter aortic valve replacement for severe aortic stenosis complicated by sigmoid septum

Background: In patients undergoing transcatheter aortic valve replacement (TAVR) for severe aortic stenosis (AS), a sigmoid septum, characterized by subaortic interventricular hypertrophy, often results in the need for new pacemaker implantation (PMI). In this study, we reviewed the feasibility and treatment efficacy of TAVR for AS in patients with a sigmoid septum. Methods and Results: Between 2011 and 2016, 48 patients (25.4%; mean age 84.9±5.4 years; 9 males) with a sigmoid septum and 141 (74.6%; mean age 82.9±5.5 years; 61 males) without underwent TAVR. Their operative outcomes, echocardiographic and electrocardiographic findings, and long-term outcomes were retrospectively compared. Second TAVR because of valve malposition was performed in 3 patients with a sigmoid septum (6.3%) and in 2 patients without a sigmoid septum (1.4%), with no significant difference between the 2 groups. Although there was no significant difference in valve hemodynamics between the 2 groups, sigmoid septum and deep implantation (implantation depth ≥10 mm) were independent predictors of new PMI following TAVR. Conclusions: Although a sigmoid septum did not preclude the feasibility, safety, or efficacy of TAVR for severe AS, its presence was associated with new PMI. Our approach to TAVR in patients with a sigmoid septum may contribute to clinical outcomes comparable to those of patients without this pathology.