The Root of All Thrombi: Coronary Artery Thromboembolism Post Heartmate3

Abstract

<h3>Introduction</h3> Aortic root thrombosis (ART) is a rare complication of left ventricular assist device (LVAD) therapy and can cause thromboembolic events. We present a case of ART complicated by coronary artery occlusion, myocardial infarction and recurrent ventricular tachycardia (VT) 2 months after HM3 implantation. <h3>Case Report</h3> 62 year old female with non-ischemic cardiomyopathy and HM3 presented 2 months post-implant with chest pain, low flow alarms, and ICD shock. Exam showed MAP 55 mm hg, pump flow 3.4 LPM, speed 5200 RPM, pulsatility index 5.2. LVAD interrogation showed multiple PI events. Her left ventricle was 5.2 cm with closed aortic valve and midline septum. TAPSE was 1.1cm. ECG showed new RBBB. Troponin T peaked at 9035 ng/dL. LDH peaked at 1361 U/L. BNP was 2194 pg/mL. INR range was 2.4-2.7 the month prior. VT initially resolved after decreasing VAD speed to 4800 suggesting suction as a trigger. She received fluids, antiarrhythmics and developed right ventricular dysfunction requiring inotrope support. Persistent chest pain and recurrent VT led to coronary angiography, which showed occlusive thrombus from aortic root to left main and left anterior descending arteries. Using embolic protection devices, clot was mechanically aspirated (Fig 1). Eleven days later, she developed an acute left posterior cerebral and basilar artery stroke. Attempted clot aspiration was complicated by intracranial hemorrhage. <h3>Summary</h3> Hemocompatibility related adverse events remain an issue with the HM 3. Lower rates of pump thrombosis were reported in the MOMENTUM trials, but thrombi can form at other sites such as outflow graft and aortic root, causing embolic complications. Closed aortic valves form a blind pouch, increasing the risk of ART especially if INR is subtherapeutic. Early imaging of the aortic root and coronary arteries should be considered for unexplained VT irrespective of coronary anatomy and risks and benefits of intervention using embolic protection devices can be considered after careful multidisciplinary evaluation.