Left atrial strain predicts paroxysmal atrial fibrillation recurrence after catheter ablation: a 1-year study using three-dimensional speckle-tracking echocardiography

Abstract

Background: Radiofrequency catheter ablation (RFCA) is a widely employed method for restoring sinus rhythm(SR) in patients with drug-refractory paroxysmal atrial fibrillation (PAF). Three-dimensional speckle tracking echocardiography (3DSTE) is a precise and practical imaging technique for clinically assessing myocardial function in the left atrium. The objective of this study was to assess alterations in three-dimensional strains and predict recurrence in patients with PAF following RFCA.

Methods: A total of 109 patients diagnosed with drug-refractory PAF and scheduled for RFCA were included in this study between September 2019 and June 2022. Conventional echocardiography and 3DSTE were performed prior to and one year(median period of 12.2 months) after RFCA. Global three-dimensional left atrial (LA) strain parameters, along with those of the left ventricle, were measured and analyzed statistically. The primary study endpoint was the recurrence of atrial fibrillation (AF).

Results: Among the 109 patients, 78 maintained a stable SR during the one-year follow-up after RFCA, while 31 experienced a recurrence of AF. Notably, patients who sustained SR demonstrated significant improvements in various LA strain parameters, including reservoir, pump, and conduit functions, compared to both their preoperative levels and those of patients who experienced recurrence(p < 0.05). Additionally, patients with sustained SR exhibited a significant reduction in LA volume compared to those with recurrence(p = 0.003). Furthermore, left ventricular global longitudinal strain (LVGLS) and left ventricular global area strain (LVGAS) of the left ventricle showed improvement while maintaining a preserved left ventricular ejection fraction (LVEF) after RFCA(p < 0.05). Our multivariate regression analysis revealed that left atrial reservoir strain (LASr) independently predicted the recurrence of AF [odds ratio (OR), 1.19, 95% confidence interval (CI), 1.05-1.35, p = 0.005]. Receiver operating characteristic(ROC) curve showed that the area under the curve(AUC) for LASr in assessing the risk of recurrence after RFCA in patients with PAF was 0.70 ( 95% CI, 0.60-0.81, P = 0.001). The calculated cutoff value was 16.5%.

Conclusions: RFCA plays a pivotal role in preserving SR and restoring LA function in patients with PAF. 3D-STE is highly effective for post-RFCA prognostic assessment. LASr, a predictive marker for the recurrence of PAF assists in the stratification of risk and contributes to informed treatment decisions, offering valuable points of reference.

Keywords: Paroxysmal atrial fibrillation; Radiofrequency catheter ablation (RFCA); Strain; Three-dimensional speckle tracking echocardiography (3DSTE).

Fig. 1

Study flow

Fig. 2

LA and LV full-volume images were obtained in apical four-chamber views, and high-quality 3D images of 4–6 cardiac cycles were recorded during sinus rhythm. LA, left atrial; LV, left ventricular; 3D, three-dimensional

Fig. 3

A landmark is precisely placed at the midpoint of the mitral annulus in three long-axis sections and one short-axis section

Fig. 4

The system automatically tracks the left atrium's endocardial border and its motion throughout the cardiac cycle

Fig. 5

3D LA parameters were generated automatically by Echopac software. 3D, three-dimensional;LA, left atrial

Fig. 6

ROC curves for LASr to predict recurrence during the follow-up period after RFCA in PAF patients. LASr, left atrial reservoir strain; RFCA, radiofrequency catheter ablation; PAF, paroxysmal atrial fibrillation; ROC, receiver operating characteristic

Fig. 7

Bland-Altman plots for evaluation of LASr in the intra- and inter-observer reliabilities. LASr, left atrial reservoir strain