Single-Center Experience With HeartMate II Left Ventricular Assist Device Explantation.

ABSTRACT

In patients with continuous flow left ventricular assist devices (CF-LVADs) myocardial recovery is uncommon. Given the heterogeneity of the population implanted and low incidence of recovery, the discovery of native left ventricular (LV) recovery and criteria for explantation of CF-LVAD system is not clearly determined. We sought to analyze the characteristics of the patients who underwent CF-LVAD explantation at our institution. Prospectively collected data on patients supported with CF-LVADs were reviewed retrospectively. Patients who underwent CF-LVAD explants were identified and their characteristics were analyzed with a focus on patient presentation and determinants of explantability. From November 2006 to June 2014, 223 patients (181 male, 42 female) underwent implantation of HeartMate II LVAD. Seven female (16.7%) and one male (0.6%) patients were explanted (P < 0.001). Mean age was 43 ± 9 years and etiology for cardiomyopathy was ischemic in three (37.5%) patients, nonischemic in four (50%) patients, and mixed in the one (12.5%) male patient of the cohort. Five (62.5%) patients presented acutely with significant hemolysis, and were found to have LV improvement as well as reduced, absent, or reversed diastolic flow velocities on echocardiography. Overall, mean lactate dehydrogenase level before explantation was 1709 ± 1168 U/L compared to the mean baseline level of 601 ± 316 U/L (P = 0.048). Mean LV ejection fraction (LVEF) improved from 17 ± 7% preimplant to 56 ± 11% pre-explantation (P < 0.001). Median number of days on CF-LVAD support was 870 (interquartile range, 209-975) while mean duration of follow-up after the CF-LVAD explantation was 276 ± 240 days. Mean LVEF dropped from 46 ± 19% postexplantation to 34 ± 10% during the most recent follow-up (P = 0.015). At our institution, patients who underwent LVAD explants were predominantly women with nonischemic cardiomyopathy. Clinical evidence of hemolysis and echocardiographic evidence of reduced or absent diastolic flow velocities were common findings in these patients. Over time, patient's native LV function declined in the absence of LVAD (after LVAD explantation). Significant challenges remain in predicting LV recovery and identifying those individuals who have recovered myocardial function significant enough to be explanted.