<div>Mitral valve leaflets abscess</div><div>Styczyński Grzegorz, MD, PhD, Medical University of Warsaw</div><div>Szmigielski Cezary, MD, PhD, Medical University of
Warsaw</div><div>Bidiuk Joanna, MD, Medical University of Warsaw, Department of Internal
Medicine, Hypertension and Vascular Diseases, UCK WUM, 1A Banacha
Street, 02-097 Warsaw, Poland. Phone +48 22 599 28 28, Fax +48 22 599 18
28. Email: jbidiuk@wum.edu.pl</div><div>Authors:</div><div>Styczyński Grzegorz, MD, PhD, Department of Internal Medicine,
Hypertension and Vascular Diseases, Medical University of Warsaw</div><div>Szmigielski Cezary, MD, PhD, Department of Internal Medicine,
Hypertension and Vascular Diseases, Medical University of Warsaw</div><div>Bidiuk Joanna, MD, Department of Internal Medicine, Hypertension and
Vascular Diseases, Medical University of Warsaw</div><div>Corresponding author:</div><div>Bidiuk Joanna, Department of Internal Medicine, Hypertension and
Vascular Diseases, UCK WUM, 1A Banacha Street, 02-097 Warsaw, Poland.
Phone +48 22 599 28 28, Fax +48 22 599 18 28. Email: jbidiuk@wum.edu.pl</div><div>Author contributions:</div><div>Styczyński Grzegorz: Concept and design, Data collection, Critical
revision of article,
Approval of article.
Szmigielski Cezary: Design, Critical revision of article, Approval of
article</div><div>Bidiuk Joanna: Drafting article, Approval of article.</div><div>Abstract</div><div>Mitral valve abscess is a well-known complication of infective
endocarditis, often requiring surgical treatment. Usually, the most
typical localization is postero-lateral mitral annulus or mitral-aortic
curtain at the base of the anterior leaflet in aortic valve
endocarditis. We describe a 64-year-old male diagnosed with the abscess
on the free margins of the mitral leaflets secondary to concomitant
vertebral osteomyelitis. A favorable resolution of the abscess during
the intravenous dual antibiotic therapy is presented.</div><div>Keywords: echocardiography, infective endocarditis (IE), mitral valve,
paravalvular abscess</div><div>Case presentation</div><div>64-years old male with the history of alcohol abuse was admitted to the
hospital because of fever, weakness and back pain. During initial
diagnostic evaluation, all three blood cultures were positive for
methicillin-sensitive Staphylococcus aureus and Streptococcus
vestibularis. Further tests for suspected endocarditis involved
transesophageal echocardiography (TEE), which showed a rounded,
bi-lobal, hyperechogenic mass localized at the tips of the both,
anterior and posterior mitral leaflets (Figure 1, panel A, B, C, Movie
S1 and S2). Concurrently, mild to moderate mitral insufficiency was
present. No signs of heart failure or systemic embolism were identified.
Intravenous antibiotics (ceftriaxone and gentamycin) were started
according to the guidelines (1). Subsequent diagnostic work-up for the
source of bacteremia, revealed additionally, a presence of the L1
vertebral osteomyelitis, with adjacent right psoas muscle abscess.
According to the cardiosurgical, orthopedic and neurosurgical
consultations, a conservative treatment with intravenous antibiotics was
recommended to be continued. A follow-up TEE performed one week later
demonstrated the disruption of the mitral mass with decrease in its size
and the occurrence of single, highly mobile structure, consistent with
bacterial vegetation on the tip of the mitral leaflet (Figure 1, panel
D,E,F, Movie S3 and S4 ). During the follow up. there was no increase in
the degree of mitral insufficiency, nor clinical signs of heart failure
or embolism. Another TEE performed after one week (i.e. 2 weeks after
initiation of antibiotics), revealed an almost complete resolution of
the mitral mass, without any significant increase in mitral
insufficiency, including no signs of perforation of the mitral leaflets
(Figure 1, panel G,H,I, Movie S5 and S6). However, at the same time,
progressive vertebral destruction led to localized spinal cord
compression requiring subsequent neurosurgical treatment.</div><div>Discussion</div><div>Prevalence of infective endocarditis (IE) in patients initially
diagnosed with infective spondylodiscitis, and systematically evaluated
with TEE is high, reaching up to 30 percent, and is associated with
significantly worse prognosis (2). In this patient, an initial
echocardiographic assessment (normal left ventricular and atrial size,
mild central mitral regurgitation) suggested no evident valvular
predisposition for infective endocarditis. This underscores the high
risk for infection of normal native valves during persistent,
significant bacteremia from distant sites, like in our patient with
infective spondylodiscitis (1). It is unclear if polymicrobial character
of bacteriemia in this patient, contributed to the increased risk of
endocardial involvement. However, based on the data from the literature,
polymicrobial bacteremia with the presence of Staphylococcus aureus and
variety of clinical manifestations, is generally associated with worse
prognosis and higher mortality, compared to monomicrobial staphylococcal
bacteremia only (3,4). Concluding, mitral valve abscess is a well-known
and severe complication of infective endocarditis, potentially
life-threatening, and often requiring surgical treatment. However, the
most typical localization is postero-lateral mitral annulus or
mitral-aortic curtain at the base of anterior leaflet in concomitant
aortic valve endocarditis (1). In this case, we describe an infrequent,
in our observation, example of an abscess on the free margins of the
mitral leaflets, with its favorable resolution during intravenous
treatment with two antibiotics. A superficial, nodular morphology of the
abscess at initial TEE examinations may suggest its early stage of
development, not yet complicated by any localized mitral leaflets
destruction.</div><div>References:</div><div>1. Habib G, Lancellotti P, Antunes MJ, et al: 2015 ESC Guidelines for
the management of infective endocarditis: The Task Force for the
Management of Infective Endocarditis of the European Society of
Cardiology (ESC). Eur Heart J. 2015;36):3075-3128.</div><div>2. Behmanesh B, Gessler F, Schnoes K, et al: Infective endocarditis in
patients with pyogenic spondylodiscitis: implications for diagnosis and
therapy. Neurosurg Focus. 2019 Jan 1;46(1):E2.</div><div>3. Khatib R, Sharma M, Johnson L, et al: Polymicrobial Staphylococcus
aureus bacteremia: Frequency, distinguishing characteristics and
outcome. Diagnostic Microbiology and Infectious Disease 2016;86:
311–315.</div><div>4. Park S, Park K, Bang K, et al: Clinical significance and outcome of
polymicrobial Staphylococcus aureus bacteremia. Journal of Infection
2012; 65:119-127.</div><div>Figure 1. Panel A – 2D TEE, mid-esophageal long axis view at 124° angle
rotation , panel B- 2D TEE, mid esophageal commissural view at 52°angle
rotation, panel C- 3D TEE modified atrial view. Thick arrows point to
mitral leaflets abscess. Panels D, E, F - respective views of the TEE
study performed 1 weeks later. Thin arrows point to the vegetation.
Panels G, H, I - respective views of the TEE study performed 2 weeks
later.</div><div>Supplementary Material: The following supplementary material is
available online - Movie Clips:</div><div>Movie S1: 2D TEE, mid-esophageal long axis view at 124° angle rotation,
Movie S2: 2D TEE, mid esophageal commissural view at 52° angle rotation,
showing rounded, bi-lobal, hyperechogenic masses localized at the tips
of the anterior and posterior mitral leaflets</div><div>Movie S3: 2D TEE, mid-esophageal long axis view at 138° angle rotation,
Movie S4: 2D TEE, mid esophageal commissural view at 74° angle rotation,
showing disruption of the mitral mass with decrease in its volume and
the presence of single, highly mobile structure consistent with
vegetation.</div><div>Movie S5: 2D TEE, mid-esophageal long axis view at 129° angle rotation,
performed 2 weeks later, Movie S6: 2D TEE, mid esophageal commissural
view at 49° angle rotation, performed 2 weeks later, showing nearly
complete resolution of the mass.</div><div>Codec used: Microsoft Video 1 (CRAM)</div>