Evaluation of micro-emboli in a patient with ventricular assist device support with hemolysis

The clinical relevance of transcranial Doppler (TCD) detection of micro-embolic signals (MES) in patients with ventricular assist devices (VADs) has been described. However, all of the previous studies concerning TCD in patients with VADs were conducted in patients with old devices; the clinical relevance of TCD in patients with newer devices has not been fully elucidated. We recently encountered a patient with a continuous-flow VAD with hemolysis. TCD monitoring was useful for the direct evaluation of micro-emboli in this patient. A 50-year-old male who underwent HeartMate II(®) VAD (Thoratec Corporation; Pleasanton, CA) implantation with a diagnosis of ischemic cardiomyopathy 15 months prior was admitted to our institution because of findings suggestive of hemolysis, such as elevated lactate dehydrogenase (LDH) and total bilirubin. Unfractionated heparin was started after admission and hemolysis gradually improved. On admission, TCD detected 146 MES during 30 min of monitoring. During the hospital course, the MES count decreased to 20 signals on hospital day 4 and further decreased to 2 signals on hospital day 15 along with decreases in LDH and total bilirubin. Since hemolysis in VAD patients is thought to be associated with thromboembolic outcomes, MES detected by TCD indicate subclinical micro-emboli. TCD monitoring may be useful for assessing the risk of thromboembolic events in newer continuous-flow VAD patients through direct visualization of micro-emboli.