Content uploaded by Andrew Michael Crean
Author content
All content in this area was uploaded by Andrew Michael Crean on Jan 15, 2016
Content may be subject to copyright.
Case Report
Spontaneous Thrombosis of a Left
Circumflex Artery Fistula Draining
Into the Coronary Sinus
Mohammad A. Al-Turki, MD
1
, Daniel Patton, MD, FRCPC
1
,
Andrew M. Crean, BSc, MSc, MPhil, FRCR
2
,
Eric Horlick, MD, FRCPC
2
, Rob Dhillon, MD, FRCPC
3
,
and Amer M. Johri, MD, MSc, FRCPC, FASE
1
Abstract
A 28-year-old woman was referred to our institution with sudden onset chest pain at rest. Electrocardiography revealed an
inferoposterior ST-segment elevation myocardial infraction. The patient proceeded to cardiac catheterization, which revealed a
large ectatic left circumflex coronary artery with an apparent fistula connecting it to the coronary sinus. Follow-up angiography
revealed that the fistula was no longer patent, spontaneously thrombosed, and resolved without requiring surgery.
Keywords
adult congenital heart disease, coronary artery anomaly, fistula, myocardial infarction
Submitted November 28, 2014; Accepted February 23, 2015.
Introduction
Coronary artery anomalies (CAAs) are rare congenital defects
in the origin, course, and/or structure of the coronary arteries.
The prevalence of CAAs in the adult population is on average
0.6%to 1%.
1
Of these anomalies, coronary artery fistula (CAF)
is a rare subtype with a prevalence of about 0.01%.
2
Coronary artery fistulas usually remain asymptomaticin nearly
half of the affected population. However, some patients develop
catastrophic sequela including congestive heart failure (CHF),
infective endocarditis, coronary aneurysmal rupture, and/or myo-
cardial infraction (MI). Treatment strategies for CAF depend on
multiple aspects, which include the patient’s age, complexity of
the anomaly, and presence of other congenital heart anomalies.
Treatment options range from conservative medical management
for small CAF to transcatheter closure when the anatomy is
amendable to intervention. Patients’ with more complex anatomy
or other congenital heart anomalies should undergo surgical clo-
sure of the CAF.
3
We describe a rare case of a fistula between the
left circumflex artery (LCX) and the coronary sinus (CS) that
resulted in MI due to spontaneous thrombosis. This unusual case
achieved clinical resolution without proceeding to surgery.
Case Report
A 28-year-old woman was visiting her family in our com-
munity while convalescing from a recent anterior cruciate
ligament repair. On assessment of her functional status, she
was noted to be a very active, competitive soccer athlete.
She presented to our institution with a sudden onset of chest
tightness at rest, one week after her knee operation. Her
electrocardiogram revealed an inferoposterior ST-segment
elevation myocardial infraction, and her troponin I level
rose to 18 ug/L.
Her past medical history was unremarkable other than the
recent surgery. She had no allergies and was only taking acet-
aminophen/oxycodone for postoperative pain. There was no
history of alcohol or illicit drug use, and there was no family
history of congenital heart disease (CHD). Her physical exam-
ination was unremarkable.
The patient proceeded to catheterization, which revealed a
large, ectatic LCX with an apparent fistula to the CS (Figure
1A). No thrombus was seen. Following the angiogram, a
1
Department of Medicine, Division of Cardiology, Queen’s University,
Kingston, Ontario, Canada
2
Division of Cardiology, University of Toronto, Toronto, Ontario, Canada
3
Department of Radiology, Queen’s University, Kingston, Ontario, Canada
Corresponding Author:
Amer M. Johri, Department of Medicine, Division of Cardiology, Queen’s
University, Kingston General Hospital, FAPC 3, 76 Stuart Street, Kingston,
Ontario, Canada K7L 2V7.
Email: amerschedule@gmail.com
World Journal for Pediatric and
Congenital Heart Surgery
2015, Vol. 6(4) 640-642
ªThe Author(s) 2015
Reprints and permission:
sagepub.com/journalsPermissions.nav
DOI: 10.1177/2150135115577432
pch.sagepub.com
Abbreviations and Acronyms
CAAs coronary artery anomalies
CAF coronary artery fistula
CHF congestive heart failure
CS coronary sinus
LCX left circumflex artery
MI myocardial infarction
computed tomography coronary angiogram confirmed a conge-
nital LCX to CS fistula (Figure 1B). Additionally, a persistent
left-sided superior vena cava was found. Echocardiography
showed a small basal inferoposterior wall motion abnormality
suggesting infarct. It also revealed a dilated CS (Figure 1C).
The patient recovered without intervention and, given the
complex nature of her anatomy, she was referred to a specia-
lized surgical center for follow-up and consideration of repair
of her fistula. She was discharged on aspirin, clopidogrel,
bisoprolol, and nitroglycerin spray as needed. At the referral
center, repeat angiography (approximately one month later)
revealed that her fistula was no longer patent, and it had pre-
sumably thrombosed at the distal end. A cardiac magnetic
resonance study confirmed the presence of a full thickness
infarct in the LCX territory (Figure 2D). The patient was ini-
tially treated with oral anticoagulation with warfarin, as well
as dual antiplatelet therapy, but warfarin was subsequently
withdrawn two months postpresentation due to concerns of
menorrhagia.
Discussion
Coronary artery fistulas are rare defects that account for
approximately 0.5%of all CHDs. It has been estimated that
42%of the case of CAF arise from the left coronary artery.
4
To our knowledge, there are fewer than 30 reported cases of
a fistulous communication between the LCX and the CS.
Myocardial infarction associated with CAFs has been
rarely reported as a presenting complaint. The majority of
CAFs, if symptomatic, present with angina pectoris, CHF,
or infectious endocarditis. The likely pathophysiology of our
patient’s MI was acute fistula thrombosis rather than coronary
steal, as is more often reported. This contention is supported
by the initial coronary angiogram showing severely delayed
opacification and reduced flow in the fistula. Filling was so
poor that even with a prolonged acquisition, the drainage to
the CS was difficult to appreciate. Why should a large fistula
suddenly thrombose in an otherwise healthy young woman?
We hypothesize that her antecedent knee surgery was the preci-
pitant. She described being entirely recumbent and immobile for
a week postoperatively, without prophylactic anticoagulation.
Reduced coronary arterial flow, in a woman who was usually
highly physically active and thus would usually have had much
higher coronary flow rates, combined with recumbency, led to
pooling and subsequent thrombus within the enlarged fistulous
vessel.
Our case is highly unusual in that, though surgical correction
for a large CAF is generally recommended,
5
the fistula under-
went spontaneous resolution prior to proceeding to surgery.
Figure 1. A, Initial angiogram demonstrating ectatic LCX artery. B, Parasternal long-axis view of a transthoracic echocardiogram shows a
dilated CS. C, Three-dimensional CT reconstruction showing route of LCX fistula to CS and persistent left SVC. LCX indicates left circumflex
coronary artery; CS, coronary sinus; CT, computed tomography; RV, right ventricle; LV, left ventricle; LA, left atrium; Ao, Aorta; LSVC, left
superior vena cava; LAD, left anterior descending coronary artery.
Al-Turki et al 641
This is the first reported case of spontaneous thrombosis of a
CAF and adds to our understanding of the variable natural his-
tory of these anomalies. It is generally thought that moderate to
large fistulas are often symptomatic at or beyond the second
decade of life. Therefore, closure in childhood (if detected ear-
lier) is generally recommended to avoid sequelae such as MI,
as occurred in our case. However, the management following
an ischemic event is less clear. Our case is an example of a sit-
uation in which surgical treatment was not required.
Transcatheter closure or surgical closure techniques have
been used based on anatomy and institutional experience/pre-
ference. Short- and intermediate-term closure rates and compli-
cations for with the two approaches are comparable and thus
require careful consideration. Complications of manipulation
of the CAF by transcatheter closure or surgical closure devices
included angina, MI, coronary thrombosis, and symptomatic
cardiomyopathy. Risk factors for thrombosis in these patients
have not been clarified in any prior studies following the treat-
ment of CAF. A study by Valente et al in their cohort of 76
patients described major coronary events in 11 patients. They
identified CAFs draining to the CS as the sole angiographic cri-
teria (P< .001), in addition to older age at diagnosis (P< .001),
tobacco use (P< .006), diabetes (P< .05), hypertension (P<
.001), and hyperlipidemia (P< .001) as predictors of adverse
outcome.
6
Of note, our case had none of these nonanatomic risk
factors. Despite this study, an adequate explanation for preva-
lence of thrombosis in these patients (and our case report) is
lacking. It is possible that a distal-type CAF with a dilated resi-
dual conduit coronary artery with potential for flow stasis is the
cause for thrombosis in these patients, irrespective of draining
site.
6
In conclusion, these studies, along with our case, show the
absolute need for long-term follow-up in such patients.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to
the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for
the research, authorship, or publication or this article: Dr Johri is sup-
ported by a Heart and Stroke Foundation of Canada Clinician Scientist
Award.
References
1. Laureti JM, Singh K, Blankenship J. Anomalous coronary arteries:
a familial clustering. Clin Cardiol. 2005;28(10): 488-490.
2. Yuksel S, Yasar E, Nar G, et al. Prevalence and characteristics of
coronary-cameral communications in adult patients: coronary
angiographic analysis of 16,573 patients. Med Princ Pract. 2014;
23(4): 336-339.
3. Armsby LR, Keane JF, Sherwood MC, Forbess JM, Perry SB, Lock
JE. Management of coronary artery fistulae. Patient selection and
results of transcatheter closure. J Am Coll Cardiol. 2002;39(6):
1026-1032.
4. Levin DC, Fellow KE, Abrams HL. Haemodynamically significant
primary anomalies of the coronary artery. Circulation. 1978;58(1):
23-34.
5. Mahesh B, Navaratnarajah M, Mensah K, Amrani M. Treatment of
high-output coronary artery fistula by off-pump coronary artery
bypass grafting and ligation of fistula. Interact CardioVasc Thorac
Surg. 2009;9(1): 124-126.
6. Valente AM, Lock JE, Gauvreau K, et al. Predictors of long-term
adverse outcomes in patients with congenital coronary artery
fistulae. Circ Cardiovasc Interv. 2010;3(2): 134-139.
Figure 2. Multimodality evaluation of LCX to CS fistula. A, Repeat
angiogram demonstrates large and tortuous vessel (arrow) arising
from the coronary tree in the expected position of the LCX. B, Mul-
tiple areas of incomplete contrast opacification (arrows) suggest the
presence of intraluminal thrombus. C, Coronal CT reconstruction
showing the course of the fistula (arrows) running alongside the CS
before terminating in its distal portion (asterisk). D, Inversion recov-
ery gradient echo late gadolinium enhancement short-axis image
showing transmural scar (arrows) in the lateral wall of the LV. CS indi-
cates coronary sinus; CT, computed tomography; LCX, left circumflex
coronary artery; LV, left ventricle.
642 World Journal for Pediatric and Congenital Heart Surgery 6(4)
