Pre-operative left atrial reservoir strain predicts adverse morphological remodeling and heart failure after left atrial appendage interventions
Y Hada, Y Matsumura, O Inaba, T Yamato, H Morita, J Matsuda, E Kurosaka, N Yanagiya, T SasanoAbstract
Background
The left atrium (LA) performs three phasic functions: reservoir, conduit, and booster pump. Left atrial reservoir strain (LASr) is a sensitive biomarker for diastolic dysfunction and cardiovascular risk, often preceding structural changes. While left atrial appendage (LAA) intervention, including surgical excision and percutaneous closure, is an established standard for stroke prophylaxis in patients with atrial fibrillation (AF), the LAA also acts as a "pressure-volume buffer" due to its 2.6-fold higher compliance compared to the LA main chamber. Eliminating this high-compliance buffer may increase wall stress and heart failure (HF) risk in patients with impaired LA reserve, although long-term structural and clinical data remain limited.
Purpose
To evaluate pre-operative LASr as a predictor of adverse LA expansion at one year and subsequent HF hospitalizations after surgical LAA excision.
Methods
We retrospectively analyzed 202 consecutive patients (62.4% male, mean age 67.5 ± 12.8 years) who underwent surgical LAA excision during cardiac surgery between March 2023 and February 2025. Transthoracic echocardiography was performed at baseline and at one-year follow-up. LA phasic function, specifically LASr, was analyzed via two-dimensional speckle-tracking (EchoPAC AFI-LA, GE Healthcare) using the R-R gating method. The patient cohort included those undergoing isolated LAA excision (5.3%), isolated CABG (21.1%), isolated valve replacement (35.1%), and other complex cardiac procedures. Subjects were categorized by baseline rhythm: sinus (73.7%), paroxysmal AF (14.0%), persistent AF (3.5%), or long-standing persistent AF (LSAF) (8.8%). Adverse remodeling was strictly defined as an absolute LA volume index (LAVI) increase ≥10 points (ml/m2) at one year. Outcomes were assessed via Kaplan-Meier analysis for unplanned HF hospitalizations.
Results
Pre-operative LASr declined stepwise with AF severity (Sinus > Paroxysmal > Persistent > LSAF, p < 0.001). At one year, no group showed significant LASr improvement, while LA expansion was most prominent in the LSAF group. Compared to the Non-Expansion Group, the Expansion Group (LAVI increase ≥10 points) had significantly lower baseline LASr and higher LSAF prevalence. Median follow-up was 554 days, with a 3.5% incidence of HF hospitalizations. Kaplan-Meier analysis revealed a significantly higher incidence of HF hospitalizations in the Expansion Group (p < 0.05). Multivariate analysis identified pre-operative low LASr as an independent predictor of post-operative LA expansion and subsequent HF.
Conclusion
LASr is a critical predictor of adverse remodeling post-LAA excision. In patients with severely impaired LASr, the LA cannot compensate for the loss of the LAA's buffer capacity, leading to structural expansion and elevated HF risk. Pre-operative LA strain assessment is essential to identify high-risk patients requiring intensive post-operative management and vigilant follow-up.