Percutaneous left atrial appendage occlusion: impact on left atrial deformation indices

Abstract

Background: Percutaneous left atrial appendage occlusion (LAAO) is an accepted alternative to thromboprophylaxis in patients with atrial fibrillation (AF) who are: (i) intolerant to oral anticoagulation (OAC) (e.g. life-threatening haemorrhage), (ii) non-adherent to OAC, or (iii) at a high bleeding risk with OAC. Improvement in LA mechanics was shown post-LAAO in the LAFIT-LARIAT study, using the Lariat device. No significant change was seen in LA mechanics after LAAO with the Watchman device in the LAFIT-Watchman study. The impact of LAAO with the Amplatzer or Amulet device on LA deformation mechanics has not been investigated.

Purpose: To evaluate the impact of LAAO with the Amplatzer or Amulet device on echocardiographic LA deformation indices.

Methods: All patients undergoing percutaneous LAAO from 2013 to 2021 at a single centre were included from an ongoing clinical registry. LA reservoir (ε_reservoir), conduit (ε_conduit) and contractile strain (ε_contractile) and strain rate (SR_reservoir, SR_conduit, SR_contractile) were assessed with two-dimensional speckle tracking echocardiography from an apical four-chamber view. Conduit and contractile strain and strain rates were only recorded for patients without AF at the time of echocardiography. Changes in LA deformation indices over time were compared with a linear mixed model.

Results: 28 LAAO recipients (mean age 73 ± 12 years, 68% male) were analysed. 5 (18%) patients had AF pre- or post-procedure. After a mean follow-up of 1.6 ± 1.4 months, the mean LA ε_reservoir increased from 10.15 ± 6.44% to 10.18 ± 8.72% (p = 0.985), the mean LA ε_conduit increased from 5.12 ± 5.48% to 5.31 ± 6.11% (p = 0.891) and the mean LA ε_contractile decreased from 5.14 ± 4.32% to 4.95 ± 5.30% (p = 0.898). During the same time interval, the mean LA SR_reservoir decreased from + 0.54 ± 0.23.s^{- 1} to + 0.48 ± 0.43.s^{- 1} (p = 0.566), the mean LA SR_conduit remained stable: -0.47 ± 0.41.s^{- 1} to -0.47 ± 0.32.s^{- 1} (p = 0.997) and the mean LA SR_contractile decreased from - 0.66 ± 0.50.s^{- 1} to -0.55 ± 0.46.s^{- 1} (p = 0.660).

Conclusion: No significant improvement in LA mechanical function was seen after LAAO with the Amplatzer or Amulet device. Different LAAO devices therefore appear to have divergent effects on LA deformation, the clinical implications of which may warrant further study.

Keywords: Atrial strain; Atrial strain rate; Echocardiography; Left atrial appendage occlusion.