Left ventricular remodeling and outcome after transcatheter aortic valve implantation in patients with small aortic annulus

Introduction

Transcatheter aortic valve implantation (TAVI) has become standard of treatment for severe aortic stenosis patients with high or intermediate risk. Limited and controversial data are available on the impact of having a small aortic valve annulus (SAA) on left ventricular (LV) remodeling and clinical outcomes after TAVI.

Purpose

To evaluate the changes in LV remodeling and function after TAVI in patients with and without SAA and to compare their mortality after intervention.

Methods

Patients who underwent TAVI between September 2011 and December 2021 and had available CT-derived aortic valve annular area data, as well as both baseline and follow-up echocardiographic assessments, were included and divided into:SAA Group: AV annular area ≤430 mm²;No-SAA group: AV annular area >430 mm².

Baseline echocardiography was performed at a median of 1 day (range 1–73 days) before the TAVI procedure, while follow-up echocardiography was conducted at a median of 192 days (range 185–206 days) after the intervention. All-cause mortality was assessed during long-term follow-up.

Results

A total of 500 patients (46 % women; median age 81 years) were included, of whom 168 had SAA (34%). Patients with SAA were predominantly female (80%) and had lower prevalence of coronary artery disease and atrial fibrillation (Table). Balloon-expandable valves were less frequently used in the SAA group.

At baseline, no difference in LV remodeling patterns were observed between the groups (p = 0.497). However, higher baseline LV ejection fraction (LVEF) (p=0.012) and global longitudinal strain (LVGLS) (p=0.031) were observed in the SAA group, along slightly smaller LV mass and volumes.

At post-TAVI follow-up, residual mean AV pressure gradient was slightly higher in the SAA group (p=0.004), while stroke volume index was similar in both groups. Regardless of annular size, LVEF and LVGLS significantly improved, as also LV mass and end-systolic volume (p<0.05). The group-by-time interaction was not statistically significant for LVEF (p = 0.092), LVGLS (p = 0.076), LV mass index (p = 0.906) or end-systolic volume index (p = 0.703), suggesting similar patterns of left ventricular reverse remodeling across the groups.

During a median follow-up of 74 months, 200 patients (40%) experienced all-cause death. Long-term mortality was similar between the SAA and No-SAA groups (39% vs. 40%). Kaplan–Meier curve analyses showed no significant difference in all-cause mortality between groups (log-rank P=0.727, Figure).

Conclusion

Significant LV reverse remodeling and systolic functional improvement occur after TAVI regardless of aortic valve annular size. Comparable long-term survival was observed between SAA and No-SAA patients supporting the safety and effectiveness of TAVI in patients with SAA.