A 40-year-old woman visited the Department of Obstetrics and Gynecology in our hospital because of a complaint of sudden dyspnea on effort.
She was previously diagnosed with endometriosis and prescribed a combination oral contraceptive pill (drospirenone/ethinylestradiol betadex, trade name; Yaz™, Bayer, Leverkusen, Germany).
Following the Kumamoto Earthquakes and subsequent aftershocks in April 2016, she spent 7 nights in a vehicle.
She noticed sudden dyspnea on effort when she walked outside the car on the 8th morning after the first earthquake.
Although she walked around for personal reasons during the daytime, she spent nights in her small car with her legs in a hanging position.
She noticed swelling and pain in her left lower extremity, and her serum D-dimer levels were 13.2 μg/mL.
Deep vein thrombosis (DVT) was suspected by her home doctor.
A contrast-enhanced computed tomography (CT)-scan revealed a contrast deficit in the bilateral pulmonary artery (Fig.2A) and in the left lower extremity (posterior tibial, soleus and gastrocnemius vein) (Fig.2B).
Her right ventricular function was intact (estimated pulmonary artery pressure=29/8 mmHg in cardiac ultrasound).
Her plasma brain natriuretic peptide and high-sense troponin T concentration levels were 97.2 pg/mL and 0.0061 ng/mL, respectively.
She was diagnosed with PTE and admitted to our department.
On admission, her blood pressure was 129/80 mmHg and her heart rate was 72 beats per minute.
Her degree of oxygen saturation (SaO2) in arterial blood gas was 97.7%.
Her body mass index was 24.4 kg/m2.
Electrocardiography and cardiac ultrasound did not indicate heart failure.
An investigation of most factors related to thrombus formation (including protein C, protein S, antithrombin, and antiphospholipid antibodies) revealed that all such factors were normal.
The discontinuation of the oral contraceptive and the administration of rivaroxaban (30 mg, daily), a direct oral anticoagulant (trade name: Xarelto™, Bayer) was initiated according to the results of the EINSTEIN-PE trial (3).
After 7 days, a follow-up contrast-enhanced CT scan revealed a reduction in the thrombosis (Fig.3).
The patient was followed up with rivaroxaban.
The patient gave her consent for the publication of this study.