Case Description
An 83-year-old male patient was referred to the cardiology department of
our hospital due to acute myopericarditis. His medical history included
hypertension, diabetes mellitus, dyslipidemia, permanent atrial
fibrillation, hyperuricemia, and benign prostatic hyperplasia.
On admission, the patient was afebrile and hemodynamically stable.
Laboratory tests showed high white blood cells (WBC) of 21.090 K/μL,
elevated level of C-reactive protein (CRP) of 7.4 mg/dL [upper limit
of normal (ULN): 0.5 mg/dL], erythrocyte sedimentation rate of 120
mm/h and an impaired renal function of 44
ml/min/1.73m2 [Glomerular Filtration Rate by the
MDRD Equation- Creatinine level: 1.6 mg/dL]. High sensitive Troponin-T
was elevated [132 pg/ml (ULN: 12 pg/ml)]. The QuantiFERON-TB Gold In
Tube test was negative for Mycobacterium tuberculosis infection.
Virological blood test for herpesviruses IgM (cytomegalovirus,
Epstein–Barr virus), enteroviruses IgM (echoviruses, coxsackieviruses),
adenoviruses IgM, parvovirus IgM and human immunodeficiency virus were
negative. COVID-19 (SARS-CoV-2) test was also negative. Thyroid hormones
were within the normal limits. Rheumatoid factor, anti-nuclear
antibodies and anti-neutrophil cytoplasmic antibodies were negative.
Echocardiography revealed a moderate circumferential pericardial
effusion. Left ventricle had a normal systolic function, while the right
ventricle had impaired systolic function [Decreased triscuid annular
plane systolic excursion (TAPSE) measured with M-mode (7mm) and
decreased peak systolic (S’) velocity of triscuid annulus (7 cm/s).
Flattened interventricular septum (D-shaped left ventricle) was also
observed at the parasternal short axis view. Inferior vena cava was
distended (27mm) with diminished inspiratory collapsibility
(<30%) (subcostal view). Subcostal view revealed a cyst-like
lesion about 3.7 X 3.5 cm over the right atrioventricular groove with
thickened walls and within it a calcified spherical formation
(Fig. 1B ). After the intravenous injection of an ultrasound
contrast agent there was a delayed entry of the contrast agent into the
lesion (Supplemental Video 1 ). Chest computed tomography showed
pericardial effusion and a lesion at the mid right coronary artery (RCA)
(Fig. 1A ). Coronary angiography revealed a giant aneurysm of
the mid-RCA (Fig. 1C ) with extravasation of the contrast media
(Supplemental Video 2 ). The patient underwent an urgent
surgical aneurysm resection and coronary artery distal bypass grafting.
After the sternotomy, the pericardium was noted to be extremely inflamed
with the presence of frank pus in the pericardial cavity (Fig.
1D) . Intraoperatively, RCA aneurysm was ruptured, while a bypass
grafting of the RCA was performed with a saphenous vein graft. The
patient died about 24 hours after the operation due to hemodynamic
instability. Pericardial fluid cultures grew methicillin-sensitive Staphylococcus aureus .
The Histology (Fig. 2 ) revealed abundant thrombotic material,
containing red blood cells and condensing fibrin, with a necrotic and
partially hyalinised vascular wall (coronary artery) locally heavily
infiltrated by transmural inflammatory cells. More recent thrombus
elements were observed on the luminal surface of the artery
(Fig. 2A, C ). Immunostaining for smooth muscle actin (SMA)
showed markedly decreased or totally absent staining for SMA, due to
loss of smooth muscle cells (Fig. 2B ). Immunostaing for elastin
fibers (Elastica IHC) showed complete loss of elastic fibers. Numerous
bacterial aggregates (clumps) were detected in Hematoxylin-Eosin (H-E)
stain (Fig. 2C ) and identified by Gram stain (Fig.
2D ). The histopathology was consistent with a “mycotic” (infected)
aneurysm of the mid-RCA.