What is the clinical evidence from this study?

Study design: Cohort. Population: Severe aortic stenosis (n=258). Intervention: Short membranous septal length (≤ 6 mm) vs. Membranous septal length > 6 mm. Primary outcome: All-cause mortality (HR 3.66, 95% CI 1.52-16.2, p=0.0012).

What question did this study set out to answer?

This research examines the impact of short membranous septal length on survival outcomes after transcatheter aortic valve replacement.

February 28, 2026

Impact of short membranous septal length on overall survival after transcatheter aortic valve replacement

Key Result

Short membranous septal length (≤6 mm) independently predicted all-cause mortality (HR 3.66; 95% CI 1.52-16.2; p=0.0012) and impaired LVEF recovery after transcatheter aortic valve replacement.

Key Points

This research examines the impact of short membranous septal length on survival outcomes after transcatheter aortic valve replacement.
Retrospective analysis of 258 patients who underwent transfemoral TAVR.
Membranous septal length was measured using contrast-enhanced CT.
Primary endpoint was all-cause mortality; secondary was composite of mortality or heart failure hospitalization.
Short MSL (≤ 6 mm) independently predicted increased mortality (HR 3.66, 95% CI 1.52-16.2, p=0.0012).
Higher rates of new-onset LBBB were observed in the short MSL group (p=0.047).
Incorporating MSL into risk models improved mortality discrimination (AUC 0.72 vs 0.67, p=0.042).

Study Design

Type

Cohort (n=258)

Structured PICO

Does short membranous septal length (≤ 6 mm) predict mortality and adverse outcomes in patients undergoing transfemoral TAVR?

Population

258 patients who underwent transfemoral transcatheter aortic valve replacement (TAVR) for severe aortic stenosis

Intervention

Short membranous septal length (MSL ≤ 6 mm) measured on preprocedural contrast-enhanced CT

Comparator

Membranous septal length (MSL) > 6 mm

Outcome

All-cause mortalityhard clinical

Short membranous septal length (≤ 6 mm) on preprocedural CT is an independent predictor of mortality, heart failure hospitalization, and impaired LVEF recovery after TAVR.

Main Result

Effect estimate: HR 3.66 (95% CI 1.52-16.2)

p-value: p=0.0012

Abstract

Transcatheter aortic valve replacement (TAVR) is an established therapy for severe aortic stenosis, although conduction disturbances, especially atrioventricular block and new-onset left bundle branch block (LBBB) remain associated with adverse outcomes. Short membranous septal length (MSL) has been linked to post-TAVR conduction abnormalities, but its prognostic significance is unclear. We retrospectively analyzed 258 patients who underwent transfemoral TAVR. MSL was measured on contrast-enhanced CT, and left ventricular ejection fraction (LVEF) was assessed at baseline, 1 week, and 1 year. The primary endpoint was all-cause mortality; secondary was a composite of mortality or heart failure hospitalization. Patients were classified by MSL ≤ 6 mm or > 6 mm. The short MSL group had higher rates of new-onset LBBB (p = 0.047), mortality (p = 0.046), and the composite endpoint (p = 0.039). MSL ≤ 6 mm independently predicted mortality (HR 3.66, 95% CI 1.52-16.2, p = 0.0012) and the composite outcome (HR 2.56, 95% CI 1.32-6.69, p = 0.0025). LVEF recovery at 1 year was significantly impaired (p = 0.035), and these findings persisted after excluding patients with LBBB or pacemaker implantation. Incorporating MSL ≤ 6 mm into a model with established risk factors improved discrimination for mortality (AUC 0.72 vs 0.67, p = 0.042; cfNRI 0.33). Short MSL was associated with impaired LVEF recovery and adverse outcomes after TAVR. MSL may serve as a simple CT-based marker for preprocedural risk stratification.

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