Background: This systematic review and meta-analysis was performed to assess the prognostic role of left atrial peak systolic longitudinal strain (LA-PLSsys) as a predictor of atrial fibrillation (AF) recurrence after catheter ablation. Methods We systematically searched major electronic databases and grey literature for studies assessing the role of preablation LA-PLSsys, measured in at least 2 segments, in post-ablation AF recurrence, after a follow up period of at least 6 months. Results: 17 eligible studies were included, resulting in 1704 patients (68.6% men) with a pooled mean age of 59.9±10.6 years, 65.9% with paroxysmal AF. Recurrence occurred in 32.7% of patients. Those without recurrence had significantly higher LA-PLSsys (pooled mean±SD: 22.22%±10.64%, weighted mean difference: 5.43%, 95%CI: 4.03-6.84%, I2: 82.7%). Subgroup analysis revealed that methodology used (echocardiographic view and segments assessed) was a significant source of heterogeneity (p=0.02), while meta-regression analysis demonstrated that the effect size was inversely related to the baseline LA volume index (p=0.004). Conclusions: Pre-ablation LA-PLSsys seems to be a useful predictor of post-ablation AF recurrence. However, data for patients with persistent AF and severe LA dilation are still lacking, thus no safe conclusion can be made for this challenging subgroup. Moreover, use of different methodology seems to introduce bias in the effort to obtain a universal cutoff value. Whether LA strain may be of clinical use, which would require better methodological definition and deriving a reference range - with adequate positive and negative predictive value for recurrence - is subject to further investigation.
