I. Tchoukina

Impact of INTERMACS Profile on Clinical Outcomes for Patients Supported With the Total Artificial Heart

BACKGROUND Insufficient data delineate outcomes for Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 1 patients with the total artificial heart (TAH). METHODS We studied 66 consecutive patients implanted with the TAH at our institution from 2006 through 2012 and compared outcome by INTERMACS profile. INTERMACS profiles were adjudicated retrospectively by a reviewer blinded to clinical outcomes. RESULTS Survival after TAH implantation at 6 and 12 months was 76% and 71%, respectively. INTERMACS profile 1 patients had decreased 6-month survival on the device compared with those in profiles 2-4 (74% vs 95%, log rank: P = .015). For the 50 patients surviving to heart transplantation, the 1-year posttransplant survival was 82%. There was no difference in 1-year survival when comparing patients in the INTERMACS 1 profile with less severe profiles (79% vs 84%; log rank test P = .7; hazard ratio [confidence interval] 1.3 [0.3-4.8]). CONCLUSIONS Patients implanted with the TAH as INTERMACS profile 1 had reduced survival to transplantation compared with less sick profiles. INTERMACS profile at the time of TAH implantation did not affect 1-year survival after heart transplantation.

Renal Function Recovery with Total Artificial Heart Support.

Heart failure patients requiring total artificial heart (TAH) support often have concomitant renal insufficiency (RI). We sought to quantify renal function recovery in patients supported with TAH at our institution. Renal function data at 30, 90, and 180 days after TAH implantation were analyzed for patients with RI, defined as hemodialysis supported or an estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m2. Between January 2008 and December 2013, 20 of the 46 (43.5%) TAH recipients (age 51 ± 9 years, 85% men) had RI, mean preoperative eGFR of 48 ± 7 ml/min/1.73 m2. Renal function recovery was noted at each follow-up interval: increment in eGFR (ml/min/1.73 m2) at 30, 90, and 180 days was 21 ± 35 (p = 0.1), 16.5 ± 18 (p = 0.05), and 10 ± 9 (p = 0.1), respectively. Six patients (30%) required preoperative dialysis. Of these, four recovered renal function, one remained on dialysis, and one died. Six patients (30%) required new-onset dialysis. Of these, three recovered renal function and three died. Overall, 75% (15 of 20) of patients’ renal function improved with TAH support. Total artificial heart support improved renal function in 75% of patients with pre-existing significant RI, including those who required preoperative dialysis.

Device Management and Flow Optimization on Left Ventricular Assist Device Support

The authors discuss principles of continuous flow left ventricular assist device (LVAD) operation, basic differences between the axial and centrifugal flow designs and hemodynamic performance, normal LVAD physiology, and device interaction with the heart. Systematic interpretation of LVAD parameters and recognition of abnormal patterns of flow and pulsatility on the device interrogation are necessary for clinical assessment of the patient. Optimization of pump flow using LVAD parameters and echocardiographic and hemodynamics guidance are reviewed.

Secondary hemochromatosis and mechanical circulatory support with a total artificial heart.

Figure 1 Laboratory evidence of severe persistent hemolysis in a patient supported witha TAH for 130 days. A 62-year-old man with non-ischemic cardiomyopathy developed cardiogenic shock, and a total artificial heart (TAH) was implanted due to profound biventricular failure. Within days of device implantation the patient developed severe hemolysis. Over the subsequent weeks, despite aggressive anticoagulation with bivalirudin, aspirin, dipyridamole and pentoxyfilline, he continued to have hemolytic anemia (mean hemoglobin [Hb] 5.7 g/dl, nadir Hb 3.1 g/dl; mean lactate dehydrogenase [LDH] 1,693 U/liter, peak LDH 2,628 U/liter) (Figure 1), receiving 37 units of packed red blood cells (RBC) and several infusions of intravenous iron sucrose over the 130 days of TAH support. The TAH parameters were within normal limits. No device malfunction or thrombosis was detected on intracardiac echocardiography or upon direct inspection of the TAH at the time of heart transplantation. Post-transplantation recovery was uneventful. Later, the patient presented with a febrile illness. Computer tomography of the abdomen revealed a hepatic lesion. Abdominal magnetic resonance imaging (MRI) demonstrated secondary hemochromatosis to the liver and spleen. The previously identified hepatic lesion represented an area of normal tissue sparing. The pancreas was not affected, favoring a secondary, rather than primary, etiology of hemochromatosis (Figure 2). In addition, iron deposition was noted in the renal cortex, a finding specific to intravascular hemolysis (Figure 3). Ferritin concentration was markedly elevated. Liver function studies showed mild transaminitis that normalized within 1 week. Because total iron concentration and transferrin saturation remained within normal limits, and there was no liver dysfunction, both hematology and hepatology consultants did not recommend treatment with phlebotomy or iron chelation as long as no further blood transfusions were required. We retrospectively identified a 68-year-old woman who was supported with TAH for 254 days. The patient had chronic hemolytic anemia, alveolar hemorrhage and