The Role of Echocardiography in Patients with Intravascular Hemolysis Due to Suspected Continuous-Flow Left Ventricular Assist Device Thrombus

Abstract

Purpose Continuous-flow left ventricular assist devices (LVAD) provide hemodynamic support for patients with advanced heart failure (HF). Some patients develop intravascular hemolysis (IVH) due to pump thrombus, although the utility of echocardiography for detecting compromised LVAD circulatory support in this setting is unknown. Methods and Materials Patients with HeartMate II LVADs presenting with IVH due to suspected pump thrombus were identified. Patients underwent echocardiography with Doppler-flow velocity (DFV) interrogation of inflow and outflow cannulae at baseline and presentation. IVH was defined as an acute rise in serum lactate dehydrogenase more than two fold from baseline with supportive clinical symptoms. Results Of 162 patients, 14 (8%) had IVH due to suspected pump thrombus. The mean age was 55±14 years, and duration between implant and presentation was 231±218 days. Eleven patients presented with hemoglobinuria, 9 with jaundice and 7 with acute HF. There was no change in mean inflow or outflow cannula systolic DFV from baseline to presentation (0.9±0.3 to 0.8±0.3 m/sec, p=0.45 and 1.3±0.3 to 1.3±0.4 m/sec, p=0.38), while diastolic DFV declined significantly (0.5±0.3 to 0.2±0.2 m/sec, p Conclusions Reduced cannula diastolic DFV identified LVAD dysfunction in patients with IVH due to suspected pump thrombus more often than other echocardiographic markers of impaired pump function, and was lower in patients presenting with acute HF.