Occam`s razor or Hickam`s dictum: A rare case of pulmonary

Occam`s razor or Hickam`s dictum: A rare case of pulmonary

QJM Advance Access published May 7, 2015
Occam’s razor or Hickam’s dictum: A rare case of
pulmonary embolism after myocardial infarction and
stroke from aortic arch thrombi
Poonam Velagapudi, MD; Mohit K Turagam, MD; Mary Dohrmann, MD
Division of Cardiovascular Medicine, University of Missouri School of Medicine, Columbia, Missouri,
USA
Short Title: Aortic arch thrombi
Figures & Tables: none
Total word count: 572
Reference count: 5
Correspondence:
Mohit K. Turagam, MD
University of Missouri Health Science Center
CE 306
5, Hospital Drive,
Columbia, MO-65212
Phone: (573) 882-2296
Fax: (573)884-7743
Email: [email protected]
All authors have no conflict of interest to declare.
© The Author 2015. Published by Oxford University Press on behalf of the Association of Physicians.
All rights reserved. For Permissions, please email: [email protected]
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Image: 2
Abstract
Aortic arch thrombi are a rare cause of systemic thromboembolism, especially with a morphologically
normal aorta. We present a 35 year old woman with myocardial infarction who developed an acute stroke
after cardiac catheterization associated with aortic arch thrombi and further complicated by pulmonary
embolism. The patient was treated with antithrombotic therapy which resulted in complete resolution of
aortic arch thrombi on follow up imaging and the patient remained stable without further thromboembolic
events at 6 month follow up.
Key Words
Aortic arch thrombus; cerebral infarction; pulmonary embolism; Myocardial infarction
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© The Author 2015. Published by Oxford University Press on behalf of the Association of Physicians.
All rights reserved. For Permissions, please email: [email protected]
Case
A 35 year old woman with history of hypertension, diabetes and smoking presented to an outside hospital
with chest pain and dyspnea on exertion. Electrocardiogram showed >1 mm of ST-elevation in inferior
leads. An urgent coronary angiography demonstrated 99% stenosis with thrombus in the distal right
coronary artery. Percutaneous coronary intervention with drug eluting stent was performed; during which
she developed right sided hemiparesis and was transferred to our facility. On exam the patient had a
Glasgow Coma Scale of 8 and intubated on a ventilator. A brain magnetic resonance (MR) imaging
depicted an acute large left middle cerebral artery (MCA) territory stroke. MR neck did not show
significant carotid artery disease. Transthoracic echocardiography (TTE) with bubble study showed
normal ejection fraction and no inter-atrial communication. Transesophageal echocardiogram (TEE)
(Figure 1A). Due to persistent hypoxemia a computed tomography (CT) angiography chest was done
which confirmed aortic arch thrombi and also showed multiple right segmental pulmonary emboli (PE).
Duplex ultrasound of lower extremities was negative for deep venous thrombosis. A workup for
malignancy, vasculitis and hypercoagulable state including factor V Leiden, homocysteine,
antiphospholipid antibody, antithrombin III, protein S, protein C was negative. The patient had a
significant allergy history to aspirin and was treated with ticagrelor. She was also started on high dose
statin, metoprolol and anticoagulation with therapeutic dose heparin and warfarin. MR angiography of the
chest, one week later showed complete resolution of the aortic thrombi and PE (Figure IB). The patient
was discharged on ticagrelor and warfarin with no recurrence during six month follow up.
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showed two large mobile thrombi in the distal segment of the aortic arch measuring 16 x 6 and 12 x 5 mm
Discussion
Occam’s razor is principle applied to modern medicine that all presenting symptoms in a patient may be
explained by a few possible causes while Hickam’s dictum suggests the likelihood of several diseases at
the same time.
Aortic arch thrombi are a rare cause of arterial embolism, mostly seen in elderly patients with significant
atherosclerotic or aneurysmal disease but very rare in young individuals with morphologically normal
aorta [1]. The exact etiology for aortic arch thrombi and pulmonary embolism in our patient is unclear as
there was no history of familial thromboembolic disease, use of hormonal therapy or pregnancy. A
complete work up for malignancy, vasculitis and hypercoagulable panel was negative. Furthermore, the
aorta showed no evidence of atherosclerotic disease and was morphologically normal on TEE. We
not be visualized on imaging precipitated by excessive smoking may have contributed to the
prothrombotic state. The cause for PE is multifactorial due to critical illness, immobility and acute stroke.
Prior case reports have demonstrated acute myocardial infarction or stroke or complication of PE with
aortic thrombus [2-4]. This is the first case report to our knowledge to report findings of aortic arch
thrombi, myocardial infarction, acute stroke and PE in a young patient. Aortic thrombus can be treated
medically with anticoagulation or thrombolytics [1]. Surgical options may be pursued when medical
therapy fails or if there is evidence of recurrent embolization [5]. Our patient was treated with
antithrombotic therapy with heparin, warfarin and ticagrelor with complete resolution of the aortic arch
thrombi and PE on MR chest one week later. The patient remained stable without further thromboembolic
events at 6 month follow up.
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hypothesize that micro-atherosclerotic ulceration or neo-intimal irregularity of the aortic arch which may
Learning Point for Clinicians
Although stroke is a life-threatening complication of cardiac catheterization, the presence of aortic arch
thrombus must be considered in the differential, especially in a young patient who presents with
myocardial infarction as early diagnosis and treatment may improve outcomes.
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References
1) Laperche T, Laurian C, Roudaut R, Steg PG. Mobile thromboses of the aortic arch without aortic
debris. A transesophageal echocardiographic finding associated with unexplained arterial embolism. The
Filiale Echocardiographie de la Societe Francaise de Cardiologie. Circulation 1997, 96(1):288-294.
2) Knoess M, Otto M, Kracht T, Neis P. Two consecutive fatal cases of acute myocardial infarction
caused by free floating thrombus in the ascending aorta and review of literature. Forensic Sci Int
2007;171:78-83
3) Nakajima M, Tsuchiya K, Honda Y, Koshiyama H, Kobayashi T. Acute pulmonary embolism after
cerebral infarction associated with a mobile thrombus in the ascending aorta. Gen Thorac Cardiovasc
4) Eguchi K, Ohtaki E, Misu K et al. Acute myocardial infarction caused by embolism of thrombus in the
right coronary sinus of Valsalva: a case report and review of the literature. J Am Soc Echocardiogr
2004;17:173-177
5) Choukroun EM, Labrousse LM, Madonna FP, Deville C: Mobile thrombus of the thoracic aorta:
diagnosis and treatment in 9 cases.Ann Vasc Surg 2002, 16(6):714-722
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Surg 2009;57:654-656
Figure Legends
Figure 1A: TEE: distal segment of the aortic arch shows two large thrombi measuring 16 x 6 mm and 12
x 5 mm
Figure 1B: MRA chest: No thrombus is noted in entire thoracic aorta or in the cardiac chambers
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254x190mm (96 x 96 DPI)