Left Atrial Appendage characteristics in patients with Persistent Atrial Fibrillation undergoing catheter ablation (LAAPAF Study)

Left atrial appendage morphofunctional indices could be predictive of arrhythmia recurrence post-atrial fibrillation ablation: a meta-analysis

BACKGROUND

Left atrium changes are implicated in atrial fibrillation (AF) substrate and are predictive of AF outcomes. Left atrial appendage (LAA) is an integral component of left atrial structure and could be affected by atrial cardiomyopathy. We aimed to elucidate the association between LAA indices and late arrhythmia recurrence after atrial fibrillation catheter ablation (AFCA).

METHODS

The MEDLINE database, ClinicalTrials.gov, medRxiv and Cochrane Library were searched for studies evaluating LAA and late arrhythmia recurrence in patients undergoing AFCA. Data were pooled by meta-analysis using a random-effects model. The primary endpoint was pre-ablation difference in LAA anatomic or functional indices.

RESULTS

A total of 34 studies were found eligible and five LAA indices were analyzed. LAA ejection fraction and LAA emptying velocity were significantly lower in patients with AF recurrence post-ablation [SMD = - 0.66; 95% CI (- 1.01, - 0.32) and SMD = - 0.56; 95% CI (- 0.73, - 0.40) respectively] as compared to arrhythmia free controls. LAA volume and LAA orifice area were significantly higher in patients with AF recurrence post-ablation (SMD = 0.51; 95% CI 0.35-0.67, and SMD = 0.35; 95% CI 0.20-0.49, respectively) as compared to arrhythmia free controls. LAA morphology was not predictive of AF recurrence post-ablation (chicken wing morphology; OR 1.27; 95% CI 0.79-2.02). Moderate statistical heterogeneity and small case-control studies are the main limitations of our meta-analysis.

CONCLUSIONS

Our findings suggest that LAA ejection fraction, LAA emptying velocity, LAA orifice area and LAA volume differ between patients suffering from arrhythmia recurrence post-ablation and arrhythmia free counterparts, while LAA morphology is not predictive of AF recurrence.

Left atrial appendage function and structure predictors of recurrent atrial fibrillation after catheter ablation: A meta-analysis of observational studies

Background

The results of studies evaluating the left atrial appendage (LAA) function and structure as predictors of atrial fibrillation (AF) recurrence after catheter ablation (CA) are contradictory. Therefore, we performed a meta-analysis to assess whether the LAA function and structure can predict the recurrence of AF after CA.

Methods

The PubMed, EMBASE, Web of Science, and Cochrane library databases were used to conduct a comprehensive literature search. Finally, 37 studies encompassing 11 LAA parameters were included in this meta-analysis.

Results

Compared with those in the non-recurrence group, the recurrence group had increased LAA volume (SMD 0.53, 95% CI [0.36, 0.71] p < 0.00001), LAA volume index, LAA orifice area, and LAA orifice short/long axis and decreased LAA emptying flow velocity (SMD -0.54, 95% CI [-0.68, -0.40], P < 0.00001), LAA filling flow velocity, and LAA ejection fraction, while there was no significant difference in LAA morphology or LAA depth.

Conclusion

Large LAA structure of pre-ablation (LAA volume, orifice area, orifice long/short axis, and volume index) and decreased LAA function of pre-ablation (LAA emptying flow velocity, filling flow velocity, ejection fraction, and LASEC) increase the odds of AF recurrence after CA.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42022324533].

Left atrial anatomical variations correlate with atrial fibrillation sources near the left atrial ridge

Introduction

Anatomical variations and characteristics of the left atrium (LA) may have a previously undescribed effect on source locations in atrial fibrillation (AF). This is the first study aiming to investigate the relationship between anatomical characteristics of the LA and non-PV sources detected by electrographic flow (EGF) mapping in patients with persistent AF.

Materials and methods

We analyzed cardiac computed tomography (CT) and EGF mapping data in patients who underwent radiofrequency catheter ablation (CA). EGF mapping is a novel method based on Horn–Schunk flow estimation algorithm, used to estimate cardiac action potential flow in the atria that can detect AF sources in patients with persistent AF. By analyzing EGF maps obtained during CA procedures, we localized non-PV sources in the LA.

Results

Thirty patients were included in this study (mean age 62.4 ± 6.8 years). Ten patients had AF sources near the LA ridge, while twenty patients had no leading source (source activity > 26%) near the LA ridge. LA anatomical characteristics, left atrial appendage (LAA) length, and ostial diameter showed no correlation with the presence of a leading source. We documented 19 patients with abutting LAA and left superior pulmonary vein (LSPV) (distance < 2 mm), and 11 patients with non-abutting LAA–LSPV (distance > 2 mm). Three out of 19 patients presented with a leading source near ridge in the abutting LAA–LSPV group, while 7 out of 11 patients presented with a leading source near the ridge in the non-abutting LAA-LSPV group (p = 0.01).

Conclusion

Our data suggests that non-abutting LAA-LSPV is associated with the presence of AF sources near the LA ridge.

Patients With Larger Left Atrial Appendage Orifice Presented Worse Prognosis Contributed by Acute Heart Failure After Left Atrial Appendage Closure

Background

Left atrial appendage (LAA) closure (LAAC) could prevent stroke in patients with atrial fibrillation. However, LAAC may impair the compliance of the left atrium and result in poor prognosis. This study aimed to comparatively evaluate the prognosis of LAAC among patients with different sizes of LAA orifice.

Methods and Results

Three hundred two consecutive patients who underwent successful LAAC were included and divided into 4 groups based on LAA orifice size that was measured using transesophageal echocardiography. Clinical outcomes including thromboembolic events, major cardiocerebrovascular adverse events, and acute heart failure (AHF) were compared among 4 quartile groups and between propensity‐score matched groups of large and small LAAs. Through follow‐up of 39.6±8.4 months, survival of thromboembolic events was similar. Survival of major cardiocerebrovascular adverse events was significantly lower in the group with the largest LAA orifice (log‐rank P <0.001), including a higher incidence of AHF with New York Heart Association class III to IV (21.4%, log‐rank P =0.009). A large LAA orifice (by cutoff) could predict major cardiocerebrovascular adverse events (hazard ratio, 3.749 [95% CI, 2.074–6.779]) in most patients, except for subgroups of those aged <65 years, with paroxysmal atrial fibrillation, and/or with failed rhythm/rate control. Further compared with a propensity‐score matched small‐LAA group, the large‐LAA orifice group still presented worse survival of AHF with New York Heart Association class III to IV (log‐rank P =0.010).

Conclusions

Patients with a larger LAA orifice presented a worse prognosis after LAAC, including a higher incidence of AHF. A large LAA orifice could predict a post‐LAAC AHF event in most patients, except for young patients, patients with paroxysmal atrial fibrillation, and/or with failed rhythm/rate control.

Registration

URL: clinicaltrials.gov ; Unique identifier: NCT04185142.

Anatomic characteristics of the left atrium in subjects undergoing radiofrequency ablation for atrial fibrillation

OBJECTIVE

To analyze the anatomic characteristics of the left atrium and pulmonary veins in individuals undergoing ablation for atrial fibrillation and to identify possible anatomic factors related with recurrence.

MATERIAL AND METHODS

We retrospectively reviewed the CT angiography studies done to plan radiofrequency ablation for atrial fibrillation in 95 patients (57 men; mean age, 65 ± 10 y). We reviewed the anatomy of the pulmonary veins and recorded the diameters of their ostia as well as the diameter and volume of the left atrium. We analyzed these parameters according to the type of arrhythmia and the response to treatment.

RESULTS

In 71 (74.7%) patients, the anatomy of the pulmonary veins was normal (i.e., two right pulmonary veins and two left pulmonary veins). Compared to patients with paroxysmal atrial fibrillation, patients with persistent atrial fibrillation had slightly larger diameter of the left pulmonary veins (left superior pulmonary vein 17.9 ± 2.6 mm vs. 16.7 ± 2.2 mm, p = 0.04; left inferior pulmonary vein 15.3 ± 2 mm vs. 13.8 ± 2.2 mm, p = 0.009) and larger left atrial volume (91.9 ± 24.9 cm³ vs. 70.7 ± 20.3 mm³, p = 0.001). After 22.1 ± 12.1 months' mean follow-up, 41 patients had sinus rhythm. Compared to patients in whom the sinus rhythm was restored, patients with recurrence had greater left atrial volume (81.4 ± 23.0 mm³ vs. 71.1 ± 23.2 mm³, p = 0.03). No significant differences in pulmonary vein diameters or clinical parameters were observed between patients with recurrence and those without.

CONCLUSION

The volume of the left atrium is greater in patients with persistent atrial fibrillation and in those who do not respond to ablation.