Left atrial function index (LAFI) and outcome in patients undergoing transcatheter aortic valve replacement

Abstract

Background: Clinical data regarding the association between the left atrial function index (LAFI) and outcome in patients undergoing transcatheter aortic valve replacement (TAVR) are limited.

Objectives: We aimed to investigate the association between the left atrial function index (LAFI) and outcome in patients undergoing TAVR.

Methods: In this retrospective multicenter study, we assessed baseline LAFI in 733 patients undergoing TAVR for severe aortic stenosis in two German high-volume centers between 2008 and 2019. Based on receiver operating characteristic curves, patients were stratified according to their baseline LAFI into two groups (LAFI ≤ 13.5 vs. LAFI > 13.5) and assessed for post-procedural outcome. The primary endpoint of our study was the 1-year all-cause mortality.

Results: Patients with a LAFI ≤ 13.5 had significantly more often atrial fibrillation (p < 0.001), lower LVEF (p < 0.001) and higher levels of NT-proBNP (p < 0.001). After TAVR, a significant improvement in the LAFI as compared to baseline was observed at 12 months after the procedure (28.4 vs. 32.9; p = 0.001). Compared to patients with a LAFI > 13.5, those with a LAFI ≤ 13.5 showed significantly higher rate of 1-year mortality (7.9% vs. 4.0%; p = 0.03). A lower LAFI has been identified as independent predictor of mortality in multivariate analysis (HR (95% CI) 2.0 (1.1-3.9); p = 0.03).

Conclusion: A reduced LAFI is associated with adverse outcome and an independent predictor of mortality in TAVR patients. TAVR improves LAFI within 12 months after the procedure. Left Atrial Function Index (LAFI) in Patients undergoing Transcatheter Aortic Valve Implantation. A Kaplan-Meier survival analysis of 1-year all-cause mortality in patients with LAFI ≤ 13.5 compared with patients with LAFI > 13.5. Comparing rates of 1-year all-cause mortality between the different LAFI groups, we found a significant association between left atrial function and mortality. LAFI Left atrial function index. B Comparison of the mean LAFI before and after TAVR. After long-term follow-up the LAFI improved significantly. LAFI Left atrial function index; FU follow-up. C Assessment of the left atrial function index using the pre-procedural transthoracic echocardiography. A Measurement of the minimal left atrial volume (LAEDV). B Assessment of the maximal left atrial volume (LAESV).

Keywords: LAFI; Left atrial function index; TAVR; Transcatheter aortic valve replacement.

Fig. 1

Study flow chart. LAFI Left atrial function index; FU follow-up

Fig. 2

Echocardiographic assessment of the left atrial volume index. Assessment of the left atrial function index using the pre-procedural transthoracic echocardiography. A Measurement of the minimal left atrial volume (LAEDV). B Assessment of the maximal left atrial volume (LAESV). C Calculation of the velocity time integral across the left ventricular outflow tract (LVOT-VTI). LAEDV Minimal left atrial volume, LAESV maximal left atrial volume, LVOT-VTI outflow tract velocity time integral

Fig. 3

Kaplan–Meier survival analysis of 1-year all-cause mortality in patients with LAFI ≤ 13.5 compared with patients with LAFI > 13.5. Comparing rates of 1-year all-cause mortality between the different LAFI groups, we found a significant association between left atrial function and mortality. LAFI Left atrial function index

Fig. 4

Comparison of the mean LAFI before and after TAVR. After long-term follow-up the LAFI improved significantly. LAFI Left atrial function index, FU follow-up

Fig. 5

Kaplan–Meier survival analysis of 2-year all-cause mortality according to the two LAFI groups including patients with midterm follow-up echocardiography images. The LAFI at follow-up showed significant association with 2-year all-cause mortality in the Kaplan–Meier survival analysis. LAFI Left atrial function index