Clinical presentation:
A 68-year-old woman with a past
medical history of mechanical mitral valve replacement, hypertension,
diabetes, obese and chronic atrial fibrillation on chronic warfarin
anticoagulation with an INR in range between 2,5 and 3,5 compliant to
medical therapy presented to the emergency room complaining of fatigue,
alteration of general condition and epistaxis.
Additionally, her past medical history included breast cancer diagnosed
1 year ago and the patient was treated with Doxorubicin. She had her
last chemotherapy session 1 week before her symptoms. No fever, nausea,
vomiting nor night sweats. Her laboratory results in the emergency room
revealed a hemoglobin of 9.2 g/dl, platelet count of 10,000/mm3 and an
INR of 2,3. Her serum creatinine and blood urea nitrogen were normal.
Subsequently, warfarin was held, and the patient received platelets
transfusion. The second day blood labs revealed a hemoglobin level of
8g/dl and a platelet count of 20000/mm3 with an INR of 1,9. Blood
transfusion was also given. Patient was not in range anymore and to
balance the risk of bleeding and valve thrombosis was the main issue
because as known mechanical mitral valve are at high risk of thrombosis.
Fondaparinux was recommended after both hematology and cardiology
discussion. Drug was suggested as a bridging therapy until the patient
had regain normal platelet levels. Fondaparinux was initiated on the 1st
day at 7.5 mg subcutaneously once daily based on a weight of 80 kg, and
a calculated creatinine clearance of 65 ml/min. Warfarin was initiated 5
days after the patient recovered from her thrombocytopenia with a normal
level of 150000/mm3 for an INR goal of 2,5–3,5. Therapeutic INR was
reached 4 days after where patient was receiving concomitant warfarin
and fondaparinux. No signs or symptoms of bleeding or thrombosis had
been exhibited. By the time fondaparinux was interpreted, patient had a
therapeutic INR of 3 and remained on warfarin alone. Cardiac ultrasound
was done revealing a good functional metallic mitral valve and a good LV
function. No complications were seen.