Low flow in the left atrial appendage assessed by transesophageal echocardiography is associated with increased stroke severity—Results of a single-center cross-sectional study

Abstract

Background

About 25% of strokes are thought to be cryptogenic. There is growing evidence that most of these cryptogenic strokes are thromboembolic and caused by an undetected atrial fibrillation. Measured slow flow in the left atrial appendage has been proposed to be an indicator for the thromboembolic risk since it is possibly associated with undetected atrial fibrillation.

Methods

We evaluated all patients (n = 909; mean of 62 years, 39% female) admitted with an ischemic stroke (84%) or transient ischemic attack to our university medical center who underwent transesophageal echocardiography examination 2012–2014. Baseline characteristics, cardio-/neurovascular risk factors, electrocardiogram monitoring data, National Institute of Health Stroke Scale values, the localization of the stroke, as well as transesophageal echocardiography findings were analyzed.

Results

Stroke severity measured by the National Institute of Health Stroke Scale in patients with a low flow in the left atrial appendage was significantly higher than in patients without left atrial appendage low flow (p < 0.001). There was a threshold phenomenon in flow velocity at about 60 cm/s above which no significant change in National Institute of Health Stroke Scale values could be observed. These patients were significantly different concerning incidence of heart failure (10.6% vs. 2.3%; p < 0.001) and atrial fibrillation (32.2% vs. 8.8%; p < 0.001). However, threshold phenomenon of left atrial appendage flow was unchanged when excluding atrial fibrillation and heart failure patients.

Conclusions

A low flow in the left atrial appendage was associated with clinically elevated stroke severity and could be indicated as an independent stroke risk factor. Further prospective studies are warranted to evaluate beneficial effects of therapeutic options in these patients also in the assumed absence of atrial fibrillation.

Keywords

Ischemic stroke left atrial appendage low flow echocardiography atrial fibrillation

Get full access to this article

View all access options for this article.

References

Roger

Lloyd-Jones

et al.

Heart disease and stroke statistics–2011 update: a report from the American Heart Association. Circulation 2011; 123: e18–e209.

Adams

Bendixen

et al.

Classification of subtype of acute ischemic stroke. Stroke 1993; 23: 35–41.

Lin

Wolf

Kelly-Hayes

et al.

Stroke severity in atrial fibrillation. Stroke 1996; 27: 1760–1764.

Hart

Diener

Coutts

et al.

Embolic strokes of undetermined source: the case for a new clinical construct. Lancet Neurol 2014; 13: 429–438.

Ntaios

Papavasileiou

Lip

GYH

et al.

Embolic stroke of undetermined source and detection of atrial fibrillation on follow-up: how much causality is there?. J Stroke Cerebrovasc Dis 2016; 25: 2975–2980.

Connolly

Ezekowitz

Yusuf

et al.

Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med 2011; 361: 2545–2559.

Patel

Mahaffey

Garg

et al.

Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med 2011; 365: 883–891.

Granger

Alexander

McMurray

JJV

et al.

Apixaban versus warfarin in patients with atrial fibrillation. N Engl J Med 2011; 365: 339–354.

Bunch

May

. Atrial fibrillation: a risk factor or risk marker?. Eur Heart J 2016; 37: 2890–2892.

10.

Blackshear

Odell

. Appendage obliteration to reduce stroke in cardiac surgical patients with atrial fibrillation. Ann Thorac Surg 1996; 61: 755–759.

11.

Agmon

Khandheria

Gentile

Seward

. Echocardiographic assessment of the left atrial appendage. J Am Coll Cardiol 1999; 34: 1867–1877.

12.

Takada

Yasaka

Nagatsuka

Minematsu

Yamaguchi

. Blood flow in the left atrial appendage and embolic stroke in nonvalvular atrial fibrillation. Eur Neurol 2001; 46: 148–152.

13.

Fatkin

Kelly

Feneley

. Relations between left atrial appendage blood flow velocity, spontaneous echocardiographic contrast and thromboembolic risk in vivo. J Am Coll Cardiol 1994; 23: 961–969.

14.

Zabalgoitia

Halperin

Pearce

Blackshear

Asinger

Hart

. Transesophageal echocardiographic correlates of clinical risk of thromboembolism in nonvalvular atrial fibrillation. J Am Coll Cardiol 1998; 31: 1622–1626.

15.

Kishima

Mine

Ashida

Sugahara

Kodani

Masuyama

. Does left atrial appendage morphology influence left atrial appendage flow velocity?. Circ J 2015; 79: 1706–1711.

16.

Landmesser

Holmes

. Left atrial appendage closure: a percutaneous transcatheter approach for stroke prevention in atrial fibrillation. Eur Heart J 2012; 33: 698–704.

17.

Gagne Brosseau

M-S

Boulanger

J-M

Leblanc

Berger

Benzazon

. Left atrium dilatation and multiple vascular territory strokes. Can J Neurol Sci 2014; 41: 704–708.

18.

Hamatani

Ogawa

Takabayashi

et al.

Left atrial enlargement is an independent predictor of stroke and systemic embolism in patients with non-valvular atrial fibrillation. Sci Rep 2016; 6: 31042.

19.

Martin

Bersohn

Waldo

et al.

Randomized trial of atrial arrhythmia monitoring to guide anticoagulation in patients with implanted defibrillator and cardiac resynchronization devices. Eur Heart J 2015; 36: 1660–1668.

20.

Samuels

. The brain-heart connection. Circulation 2007; 116: 77–84.

21.

Mochmann

H-C

Scheitz

Petzold

et al.

Coronary angiographic findings in acute ischemic stroke patients with elevated cardiac troponin. Circulation 2016; 133: 1264–1271.

22.

Fang

Wang

Liu

Cheng

. The efficacy and safety of high-dose statins in acute phase of ischemic stroke and transient ischemic attack: a systematic review. Intern Emerg Med 2017; 12: 679–687.

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.24 MB