Authors Michael Sunnaa MD1, Vanessa Fu MD1, Shveta Thakkar MD1, Frank Tenuto MD1
Case
A 41 year old female with a past medical history of systemic lupus
erythematosus (SLE), triple-positive antiphospholipid syndrome (APLS),
and prior right lower extremity deep vein thrombosis (DVT) presented to
the emergency department with right lower extremity swelling, cough, and
lightheadedness. Of note, the patient reports compliance with her
rivaroxaban, and she was not on any immunosuppressive therapy for her
lupus after being lost for follow-up years prior. Vitals on arrival were
notable for tachycardia, and initial labs showed pancytopenia. A
Computed Tomography Pulmonary Arteriogram (CTPA) was obtained (figures
1-3).
Figure 1: Coronal CTPA of the chest
Figure 2: Sagittal CT of Chest
Figure 3: Axial CTPA of Chest
Question
What is the finding?
A. Left Ventricular Aneurysm B. Aortic Root Abscess C. Mitral valve mass D. Ventricular septal defect E. Aortic Dissection
Answer
Answer C - Mitral valve mass
Discussion
Figure 4: Circled mitral valve mass (hypodensity)
The CT findings were suggestive of a mitral valve mass (answer C),
and further work up with an echocardiogram confirmed a 10 mm x 9.1 mm
mass on the atrial surface of the posterior mitral valve leaflet (figure
5) with unremarkable findings on the other cardiac valves. Given her
rheumatologic history this mass was suspicious for Libman Sacks
Endocarditis (LSE). Another possibility for this patient’s mitral valve
mass outside of LSE was infective endocarditis (IE). The patient’s
hospital course was complicated by intermittent fevers and hypotension,
and she was empirically treated for infective endocarditis. Blood
cultures prior to antibiotic administration revealed no growth, and
patient denied history of intravenous drug use. Thus, given her
rheumatologic history, there remained high concern for LSE, for which
she was started on hydroxychloroquine and prednisone. She was
transitioned from rivaroxaban to low molecular weight heparin given her
history of APLS and DVT. The patient was also discharged on IV
antibiotics since her Duke's Criteria were consistent with ‘possible for
IE’ given her fever, vascular phenomena (splenic infarcts on CT) and
evidence of endocardial involvement.
Libman-Sacks endocarditis is a form of nonbacterial thrombotic
endocarditis (NBTE) which involves the presence of sterile vegetations
on the heart valves. The initial process of LSE development appears to
be endothelial injury in the setting of hypercoagulable state1, which
in our case is both SLE and APLS. Vegetations in LSE are frequently
left-sided with two-thirds of cases involving the mitral valve, however,
up to a quarter involve the aortic, and less commonly, both valves2.
SLE is frequently accompanied by the presence of APLS, which is
associated with a higher prevalence of valvular abnormalities in SLE
patients3 which was also observed in our patient. Given our
patient has a history of triple positive APLS, this put her at higher
risk of NTBE than single or double positive APLS4.
Overall, this case exhibits the left-sided and more specifically the
mitral preference of LSE and the difficulties in diagnosing LSE vs IE,
while also showcasing the importance of using the modified Duke’s
Criteria in a patient with whom may be diagnosed as only LSE. LSE and IE
share similarities in that they both lead to valvular damage and
vegetations1, and that both conditions can lead fevers, malaise, and elevated inflammatory markers5.
Ultimately, to differentiate between IE and LSE, a thorough evaluation
is needed. Reviewing the patient's medical history and clinical
judgement can help guide further. Other clinical features such as of
positive blood cultures, or which valves are affected can provide
further clues to the underlying etiology. But as evidenced in our case,
IE was still “possible” by Duke’s criteria, and thus needed to be
accounted for and treated for simultaneously to LSE.
Figure 5: Echocardiogram demonstrating mitral valve mass
References
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