Elsevier

Heart Rhythm

Volume 11, Issue 9, September 2014, Pages 1522-1527
Heart Rhythm

Impact of left atrial appendage morphology on peri-interventional thromboembolic risk during catheter ablation of atrial fibrillation

https://doi.org/10.1016/j.hrthm.2014.05.022Get rights and content

Background

Left atrial appendage (LAA) morphology recently has been suggested to influence thromboembolic risk in patients with atrial fibrillation (AF).

Objective

The purpose of this study was to examine the impact of LAA morphology on peri-interventional thromboembolic events in patients undergoing AF catheter ablation.

Methods

Of 2570 consecutive patients undergoing AF ablation, 17 patients with cerebral thromboembolic events within 30 days of AF ablation were selected and matched for CHA2DS2VASc score, peri-interventional anticoagulation, and procedural characteristics with 68 event-free patients. LAA morphology was visualized by cardiac computed tomography and classified into 4 types: cactus, chicken wing, windsock, and cauliflower.

Results

Baseline, echocardiographic, and procedural characteristics of both patient groups were similar. Patients with embolic complications had a significantly higher incidence of chicken wing morphology compared to event-free controls (65% vs 21% chicken wing, 18% vs 24% cactus, 12% vs 13% windsock, 5% vs 42% cauliflower, respectively, P < .001), which translates into a >7× higher risk compared to other morphologies (odds ratio 7.2, 95% confidence interval 1.353–38.328, P = .021) when adjusted for possible confounders associated with chicken wing morphology.

Conclusion

LAA chicken wing morphology is associated with higher periprocedural thromboembolic risk in patients undergoing AF ablation. Further studies are needed to determine the mechanisms and possible implications of this observation.

Introduction

Atrial fibrillation (AF) is generally acknowledged as 1 of the most important causes of cerebral thromboembolic events.1 Multiple risk factors and different risk assessment models have been proposed,2, 3 but the predictive value of those schemes is still limited when applied to real-world populations4 or so-called low-risk patient groups.5

Because the left atrial appendage (LAA) plays a major role as a thromboembolic source6 in patients with AF, its impact on thromboembolic risk has been addressed. LAA morphology, which recently has been classified into four types (cactus, chicken wing, windsock, and cauliflower), has been suggested to influence thromboembolic risk in AF patients7, 8, 9 and to provide additional value in predicting thromboembolic events in low-risk patient groups.10

The risk of thromboembolic events is also present or even increased during and early after AF catheter ablation.11, 12 Although different pathophysiologic mechanisms and anatomic predispositions may determine the risk of such an event in this specific setting, the role of the LAA and its morphology has not been taken into account.

The aim of this case control study was to examine the impact of LAA morphology on peri-interventional thromboembolic risk in patients undergoing AF catheter ablation.

Section snippets

Patients

Of 2570 patients undergoing AF ablation between 2007 and 2012 at our institution, 17 consecutive patients with cerebral thromboembolic events within 30 days of AF ablation were selected and matched for CHA2DS2VASc score criteria (congestive heart failure, hypertension, age, diabetes mellitus, prior stroke/TIA, and vascular disease) and peri-interventional anticoagulation and procedural characteristics with randomly chosen 68 event-free patients (1:4 ratio). Table 1 lists the baseline

Patient characteristics of different LAA morphologies

In the whole population, the following distribution of 4 morphology types was observed: 19 patients (22%) had cactus morphology, 25 patients (29%) chicken wing, 11 patients (13%) windsock, and 30 patients (35%) cauliflower. Satisfactory level of interobserver agreement was reached (κ 0.70, 95% CI 0.38–0.90, P < .001).

Baseline characteristics and medication and procedural data were not significantly different in patients with different LAA types (Online Supplemental Table 1). However, the

Main findings

To the best of our knowledge, this is the first study illustrating the impact of LAA morphology on peri-interventional thromboembolic risk associated with catheter ablation of AF. In this case control study, we observed chicken wing morphology to be associated with a 7× higher risk of peri-interventional thromboembolic event. This association remained significant after adjustment for possible confounders associated with chicken wing morphology.

Influence of LAA morphology on peri-interventional thromboembolic risk

The impact of different LAA morphologies on

Conclusion

The chicken wing morphology of LAA is associated with higher periprocedural thromboembolic risk in patients undergoing AF ablation. Further studies are needed to illuminate the pathophysiologic mechanisms and clinical implications of this phenomenon.

Cited by (0)

The first two authors contributed equally to this work.

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