Clinical Case 10—An unusual case of thrombocytopenia following transfemoral aortic valve implantation

Abstract

Abstract Clinical Case: An 85-year-old female patient with diabetes, hypertension, obesity, chronic kidney disease and severe aortic stenosis was submitted to transcatheter aortic valve implantation (TAVI). During procedure unfractionated heparin was administered. Intervention was performed without complications and she was discharged with platelet count of 116,000/μL. Fifteen days after (day 0), she was readmitted with dyspnea. Arterial blood gas showed hypoxemia and lactate levels of 5,8mmol/L. The ECG showed new-onset atrial fibrillation (AFib) with a rapid ventricular rate. Blood tests showed platelet count of 45,000/μL, D-dimers 2790ng/mL, worsening kidney function and high inflammation markers. An echocardiogram showed normofunctioning transcatheter aortic valve. Pulmonary embolism (PE) or respiratory infection with new-onset AFib were admitted. The patient started enoxaparin and an antibiotic. On day 4 the patient was oliguric needing dialysis. A CT Angiography was performed that excluded PE but showed several thrombus on the right atrium and appendix, right ventricle and on the abdominal aorta. Blood results showed hemolytic anemia. On day 8, the platelet count reached the nadir of 11 000/μL. At that time, differential diagnoses included thrombotic thrombocytopenic purpura (TTP), heparin-induced thrombocytopenia and sepsis-induced disseminated intravascular coagulation (DIC). Laboratory evaluation showed a near-normal coagulation profile and a PF4+ antibody. Enoxaparin was stopped; fondaparinux and plasma therapy were started. Platelet count took weeks to reach previous levels. The patient was discharged with a DOAC. It is usual to have some degree of thrombocytopenia after TAVI. In this case we have a complex and challenging scenario, properly handled, and with a good outcome.