Case Presentation
A 70-year-old female patient with hypertension, dyslipidaemia, diabetes
mellitus, and no allergic history presented to our emergency care centre
with nausea and chest pain 15 min after her second dose of the
Pfizer-BioNTech COVID-19 vaccine. Physical examination revealed
peripheral cyanosis and the following vital signs: heart rate, 57
beats/min; blood pressure, 84/67 mmHg; respiratory rate, 22 breaths/min;
oxygen saturation, 97% in room air; and temperature, 35.6℃. Lung and
cardiac auscultation findings were normal.
An initial electrocardiogram (Fig. 1) showed ST-segment elevation in II,
III, and aVF and a first-degree atrioventricular block. Transthoracic
echocardiograms showed inferior wall hypokinesia. Chest radiography
revealed clear bilateral lung fields. Her cardiac enzymes including
inflammatory markers (white blood cell count and C reactive protein
level) were still normal, showing no acceleration of blood coagulation
(D-dimer and fibrinogen). An urgent catheter examination (Fig. 2) showed
total occlusion in the right coronary artery (RCA) #3 and 90% stenosis
in the left anterior descending artery (LAD) #7.
After catheterisation, percutaneous coronary intervention was performed
on the RCA lesion. A red thrombus was obtained by thrombectomy, and the
occlusion was released. A new distal occlusion was found in the fourth
posterolateral branch artery (#4PL) and posterior descending artery
(#4PD) of the RCA (Fig. 3) with residual ST-segment elevation in II,
III, and aVF. Intravascular ultrasonography (IVUS) did not identify any
obvious plaque rupture whereas continuous diffuse plaques and some
unstable like lesions were observed (Fig. 3). TIMI III blood flow was
obtained, and there were large amount of blood clots and distal
embolization. Therefore, we did not place a stent, but instead placed
intra-aortic balloon pumping (IABP) and returned to the ward.
The next day, optical coherence tomography (OCT) was performed to
evaluate the unstable vessel. On coronary angiography, the #4PD/PL
thrombus had disappeared (Fig. 4). Thrombus and vasa vasorum in the
plaque layer (Fig. 4) were observed by OCT, indicating an unstable
lesion. Therefore, we implanted a drug-eluting stent in the lesion where
the vasa vasorum were present. IABP was discontinued after the
intervention. During hospitalisation, the LAD lesion was treated using
percutaneous coronary intervention. The patient was on medications,
including high-dose statins, for the treatment of myocardial infarction
and was recovering well; she was discharged on day 13 following the
Japanese Circulation Society guideline. The thrombus contained atheroma
with cholesterol crystals and foam cells (Fig. 5).