Atrial fibrillation, not atrial cardiopathy, is associated with stroke: A single center retrospective study
Introduction
Atrial fibrillation (AF) is a commonly diagnosed cardiac arrhythmia with an estimated prevalence of 49–96 cases per 1000 person-years. [1] AF increases the annual risk of thromboembolism to as high as 6%, which is about 7 times greater than seen with sinus rhythm [2]. AF is further associated with a four-fold increased prevalence of ischemic stroke, prompting an assessment for AF in all patients who present with stroke. [3,4]
Increased size of the left atrium, the prevalence of which is estimated to be about 32%, is associated with new onset AF. [[5], [6], [7]] Left atrial enlargement (LAE) has been reported as a risk factor for incident [[8], [9], [10]] and recurrent stroke [11,12], especially in cases of cryptogenic and cardioembolic stroke with documented AF. [[13], [14], [15]] The Cardiovascular Health Study data has called into question whether LAE is independently associated with stroke. [16] [17].
The significant stroke risk associated with AF is well documented, and while it is known that LAE is a risk factor for developing AF, it remains unclear to what extent structural atrial pathology may contribute to stroke risk in the absence of AF. Atrial cardiopathy, defined as left atrial enlargement (LAE) with associated structural and physiological changes, has been proposed to be the unifying risk factor for AF and cardioembolic stroke. Atrial cardiopathy is defined as LAE on echocardiography, increased p-wave terminal force in lead V1 (PTFV1) on electrocardiography, or increased serum levels of brain natriuretic peptide (NT-proBNP) [18,19].
The extent to which atrial cardiopathy is associated with stroke in the absence of AF has not been fully evaluated. In this study, we sought to better understand the relative associations of LAE and AF with stroke.
Section snippets
Study setting and population
This retrospective study was conducted between March 6th to September 6th, 2016 at Henry Ford Health System (HFHS) in South-East Michigan. The health system is composed of five acute care hospitals, four free-standing emergency departments, and over 38 outpatient facilities. All patients who underwent transthoracic echocardiography (TTE)within this period were included in the analysis, regardless of indication, and regardless of the clinical setting (i.e. inpatient versus outpatient). TTE were
Results
A total of 8679 cases were included in the study. Mean age was 65 ± 17 years with a range from 16 to 103; 54% were female and 41% were African American. Fifty-five percent of patients had normal LA size, 15% had mild, 12% had moderate and 18% had severe LAE. Age, hypertension, diabetes, congestive heart failure, peripheral vascular disease, atrial fibrillation, CHADS2-Vasc scores, lower ejection fraction, and use of antiplatelet and anti-coagulation medications were all significantly associated
Discussion
In this large retrospective cross-sectional study, we found that the LAE found on routine echocardiography is strongly associated with a previous diagnosis of AF. We also confirmed that AF is associated with a history of stroke. By contrast, structural enlargement of the left atrium, found in almost half of the population, had no association with stroke, regardless of its severity, and regardless of the presence or absence of AF. These findings challenge the concept of atrial cardiopathy as the
Conclusion
Presence of LAE found on routine echocardiography is strongly associated with prevalent AF. Structural LAE, found in almost half of the population, represents a significant increasing association with occult AF, however, AF, not LAE, appears to be the true atrial factor associated with stroke.
Acknowledgments
None.
Sources of funding
No funding was received for this study.
Disclosures
S.A.M. has received consulting fees from Biogen.
References (39)
- et al.
50 year trends in atrial fibrillation prevalence, incidence, risk factors, and mortality in the Framingham Heart Study: a cohort study
Lancet
(2015) - et al.
Status of the epidemiology of atrial fibrillation
Med. Clin. North Am.
(2008) - et al.
Left atrial volume in the prediction of first ischemic stroke in an elderly cohort without atrial fibrillation
Mayo Clin. Proc.
(2004) - et al.
A simple score for predicting paroxysmal atrial fibrillation in acute ischemic stroke
J. Neurol. Sci.
(2013) - et al.
The influence of left atrial enlargement on the relationship between atrial fibrillation and stroke
J. Stroke Cerebrovasc. Dis.
(2016) - et al.
American Society of Echocardiography recommendations for quality echocardiography laboratory operations
J. Am. Soc. Echocardiogr.
(2011) Smoking and risk of atrial fibrillation
J. Cardiol.
(2018)- et al.
The natural history of atrial fibrillation: incidence, risk factors, and prognosis in the Manitoba Follow-Up Study
Am. J. Med.
(1995) - et al.
Smoking and risk of atrial fibrillation in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study
J. Cardiol.
(2018) - et al.
Left atrial dimensions determined by M-mode echocardiography in black and white older (> or =65 years) adults (The Cardiovascular Health Study)
Am. J. Cardiol.
(2002)
Thromboembolic complications in atrial fibrillation
Stroke
Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals from the American Heart Association/American Stroke Association
Stroke
Prevalence of echocardiographic left-atrial enlargement in hypertension: a systematic review of recent clinical studies
Am. J. Hypertens.
Echocardiographic predictors of nonrheumatic atrial fibrillation. The Framingham Heart Study
Circulation
Incidence of and risk factors for atrial fibrillation in older adults
Circulation
Left atrial size and the risk of stroke and death. The Framingham Heart Study
Circulation
Left atrial size and the risk of ischemic stroke in an ethnically mixed population
Stroke
Left atrial enlargement and stroke recurrence: the Northern Manhattan Stroke Study
Stroke
Left atrial size and risk of recurrent ischemic stroke in a Chinese population
Brain Behav.
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