Predictive value of peak left atrial reservoir strain combined with left atrial appendage flow velocity for atrial fibrillation recurrence after pulsed field ablation.

backgroundThe recurrence rate after ablation for atrial fibrillation (AF) remains high, and the predictive performance of existing predictors is limited. Left atrial dysfunction plays a key role in the occurrence and progression of AF. However, studies on predictors of recurrence after pulsed field ablation (PFA) remain relatively limited, particularly comprehensive assessments combining left atrial strain parameters with left atrial appendage flow velocity.

methodsClinical data from 246 patients with AF who underwent PFA between June 2021 and June 2024 were retrospectively analyzed. Preoperative peak left atrial reservoir strain (LASr) was measured using two-dimensional speckle-tracking echocardiography (2D-STE), and left atrial appendage flow velocity (LAAV) was measured using transesophageal echocardiography (TEE). The follow-up cutoff date was December 30, 2024, and the median follow-up duration was 17.3 (10.8, 25.6) months. Recurrence of AF, atrial flutter, or atrial tachycardia after the blanking period was recorded. A predefined multivariable Cox proportional hazards model was used to identify independent predictors, and model performance was evaluated using the 18-month time-dependent receiver operating characteristic (ROC) curve, Kaplan-Meier method, and bootstrap internal validation.

resultsDuring follow-up, 68 patients (27.6%) experienced recurrence of atrial arrhythmia after the blanking period. Both LASr and LAAV were lower in the recurrence group than in the non-recurrence group (both P < 0.001). Predefined multivariable Cox regression analysis showed that LASr (per 1% increase: hazard ratio [HR] = 0.891, 95% confidence interval [CI]: 0.842-0.943, P < 0.001) and LAAV (per 1 cm/s increase: HR = 0.972, 95% CI: 0.956-0.989, P = 0.001) were independent predictors of AF recurrence after PFA; AF duration did not reach statistical significance after adjustment (HR = 1.005, 95% CI: 0.996-1.014, P = 0.268). The 18-month area under the curve (AUC) of the baseline clinical model constructed with persistent AF, AF duration, and left atrial volume index (LAVI) was 0.752 (95% CI: 0.687-0.817). After adding LASr and LAAV to the baseline model, the 18-month AUC increased to 0.891 (95% CI: 0.849-0.933), outperforming the baseline model (bootstrap P < 0.001) and improving reclassification ability (net reclassification index [NRI] = 0.438, 95% CI: 0.286-0.590; integrated discrimination improvement [IDI] = 0.158, 95% CI: 0.108-0.208; both P < 0.001). Based on LASr ≤ 22.3% and LAAV ≤ 45.2 cm/s, the 18-month recurrence-free rates in the low-, intermediate-, and high-risk groups were 88.7%, 70.5%, and 36.1%, respectively.

conclusionsLASr and LAAV were independent predictors of AF recurrence after PFA, and their combination provided incremental predictive value beyond conventional clinical factors. Risk stratification based on LASr ≤ 22.3% and LAAV ≤ 45.2 cm/s may be used for preprocedural risk communication and assessment of postprocedural follow-up intensity; however, whether this approach can guide changes in ablation strategy and improve outcomes requires validation in prospective studies.