A 71-year-old female with heart failure who underwent left ventricular assist device (LVAD) placement presented for evaluation of low hemoglobin and dark stools. She also had leg pain, numbness, and weakness for which she was taking ibuprofen. She was found to have a gastrointestinal bleed, INR of 4.3, and arterial thrombi in the left leg. She was stabilized, had her anticoagulation held, and underwent mechanical thrombectomy. On hospital day 6, LVAD interrogation revealed signs of thrombosis, while subsequent labs revealed a persistently supratherapeutic INR of 5.2.

The patient had the LVAD removed and underwent further hematologic workup. Her platelets remained normal throughout the admission, indicating this was not acute disseminated intravascular coagulation (DIC), thrombotic thrombocytopenic purpura (TTP), or heparin induced thrombocytopenia (HIT). Echocardiography identified it as a primary thrombus.

This case illustrates the importance of appropriate anticoagulation to balance the bleeding risk with the risk of thrombi, as well as the importance of maintaining high suspicion for LVAD thrombosis regardless of INR.