Effect of Rivaroxaban on Fibrinolytic Therapy in Massive Pulmonary Embolism: Two Cases
A 73-year-old woman was admitted to our hospital with a 1-month history of dyspnea and poor oral intake. She had felt mild dyspnea on exertion without progression since last year. The aggravation of dyspnea on exertion started 1 month ago. She had a disability in walking because an event of cerebral hemorrhage occurred 2 years ago and an event of cerebral infarction occurred 1 year ago. She was never a smoker and was on medication due to hypertension for 2 years. On admission, blood pressure was 100/60 mm Hg, heart rate was 81 beat/min, respiratory rate was 18 breath/min, body temperature was 36.4℃. Her blood pressure decreased to 80/50 mm Hg and lasted over 1 hour on the next day. aBGA on room air was 7.505 in pH, 23.1 mm Hg in PaCO2, 64.6 mm Hg in PaO2, 17.8 mmol/L in HCO3-, and 94.8% in O2 saturation. Echocardiography showed RV hypokinesia with a D-shaped LV and pulmonary hypertension. A CT pulmonary angiogram with a lower extremity CT venogram showed massive bilateral PE with lung infarction and DVT in the right superficial femoral vein extending to the popliteal vein (). A brain CT showed an old infarction sequelae in the right frontal lobe, basal ganglia and cerebellum. D-dimer, NT-pro-BNP, and high sensitive troponin-T were 1,190 ng/mL (range, 0-243 ng/mL), 17,481 pg/mL (range, 0-97.3 ng/mL), and 0.036 ng/mL (range, 0-0.015 ng/mL), respectively. Since previous intracranial hemorrhage is one of the major contraindications to the use of fibrinolytic therapy, high dose UFH alone was administered instead of a fibrinolytic agent. On the day following the high dose UFH injection, dyspnea was much improved in spite of no change in hemodynamic parameters. High dose UFH was replaced with rivaroxaban 15 mg twice daily. After 3 days of medication with rivaroxaban alone, the dyspnea was worsened and repeated aBGA on oxygen 6 L/min with an oxygen mask with a reservoir bag was 7.455 in pH, 19.3 mm Hg in PaCO2, 54.3 mm Hg in PaO2, 13.3 mmol/L in HCO3-, and 90.7% in O2 saturation. A high dose of UFH was administered again after the rivaroxaban was stopped for 4 days. Dyspnea was slightly improved without a change in the thrombus burden on follow-up CT scan and hemodynamic parameters (). We assumed that reversal of the RV failure outweighed the increased bleeding following fibrinolytic therapy. On the next day, rt-PA with 100 mg was administered via a peripheral vein for 2 hours while a high dose of UFH was withheld. Dyspnea was much improved without major bleeding complications and hemodynamic parameters showed marked improvement (). She has been taking warfarin after fibrinolytic therapy and denied dyspnea on exertion.