Outcomes and hospital admissions during long-term support with a HeartMate II.

OBJECTIVES: Continuous-flow left ventricular assist devices like the HeartMate II (HMII) improves survival in severe heart failure but little is known about the incidence and causes of hospitalizations during long-term support which was evaluated in this study. DESIGN: Observational follow-up study comprising all patients who received a HMII at our institution either as bridge-to-transplantation (BTT) or destination therapy (DT). All patients were followed from HMII implantation to transplantation, device explantation, death, or May 2015. RESULTS: The HMII was implanted in 66(44 BTT, 22 DT) patients with a median (range) duration of support since implantation of 329(2-2707) days with 260(2-1080) days in the BTT group and 608(6-2707) days in the DT group. Thirty-day mortality was 12% and one-year survival 76%, comparable for DT and BTT. Among 56 (19 DT and 37 BTT) patients discharged alive with a HMII there were 161 hospital readmissions during a follow-up of 336(37-2682) days corresponding to a hospitalization rate of 1.3(0-19) per patient year and with a length of stay of 5(2-72) days per admission. Most frequent cause of readmission was infections (29%). A history of atrial fibrillation was the only independent factor associated with increased readmission rates. CONCLUSIONS: Our single-center study demonstrated encouraging survival following HMII implantation. Hospital readmissions were frequent, mostly of short duration, mainly due to infections and increased in patients with atrial fibrillation.

Effect of increasing pump speed during exercise on peak oxygen uptake in heart failure patients supported with a continuous-flow left ventricular assist device. A double-blind randomized study.

AIMS: Continuous-flow left ventricular assist device (CF-LVAD) implantation is associated with improved quality of life, but the effect on exercise capacity is less well documented. It is uncertain whether a fixed CF-LVAD pump speed, which allows for sufficient circulatory support at rest, remains adequate during exercise. The aim of this study was to evaluate the effects of fixed versus incremental pump speed on peak oxygen uptake (peak VO2) during a maximal exercise test. METHODS AND RESULTS: In CF-LVAD (HeartMate II) patients exercise testing measuring peak oxygen uptake (VO2) was performed on an ergometer bike twice in one day: once with fixed pump speed (testfix) and once with incremental pump speed (testinc). The order of testfix and testinc in each patient was determined by randomization. During testinc pump speed was increased from the baseline value by 400 rpm/2 min. Fourteen patients (aged 23­69 years) were included with a mean support duration of 465±483 days. Baseline CF-LVAD speed was 9357±238 rpm and during testinc speed was increased by a mean of 1486±775 rpm. Mean peak VO2 was significantly higher in testinc compared with testfix (15.4±5.9 mL/kg/min vs. 14.1±6.3 mL/kg/min; P=0.012), corresponding to a 9.2% increase. All exercise tests (n=28) were adequately performed with RER>1. CONCLUSION: Increasing pump speed during exercise augments peak VO2 in patients supported with CF-LVADs. An automatic speed-change function in future generations of CF-LVADs might improve functional capacity.

Right ventricular failure after implantation of a continuous-flow left ventricular assist device: early haemodynamic predictors.

OBJECTIVES: Right ventricular failure (RVF) is a significant complication after implantation of a left ventricular assist device. We aimed to identify haemodynamic changes in the early postoperative phase that predicted subsequent development of RVF in a cohort of HeartMate II (HMII) implanted patients. METHODS: This was a single-centre observational study of consecutive placement of HMII devices at Rigshospitalet, Copenhagen. Preoperative data (right heart catheterization, biochemistry and clinical status) and postoperative readings from the first 72 h after implantation (haemodynamics, inotropic and vasoactive therapy) were included in the analysis. The data set was examined for significant differences between patients who developed RVF (RVF group, n = 11)-defined as need for inotropic or vasodilator therapy >14 days, nitric oxide therapy ≥ 48 h or right ventricular assist device therapy-and those who did not (non-RVF group, n = 22). RESULTS: Preoperative right heart catheterization data were similar in the two groups. Immediately after HMII implantation, the increase in cardiac index (CI) was significantly larger in the non-RVF than in the RVF group (0.96 ± 0.8 vs 0.2 ± 0.5 L/min, respectively; P = 0.018), whereas right ventricular stroke work index (RVSWI) decreased significantly more in the RVF group (-4.3 ± 2.0 vs -0.9 ± 2.0 g m/m(2); P < 0.001). These differences were present in spite of the RVF group receiving larger doses of catecholaminergic agents (P = 0.034). Over the ensuing 72 h, the CI of the RVF group gradually approached that of the non-RVF group; concurrently, however, the differences in inotropic therapy were further enhanced. Pump settings were similar in the two groups. CONCLUSIONS: The haemodynamic alterations characterizing RVF were present already immediately after HMII implantation. RVF development was not related to pump flow and settings.

Long-term outcome in patients treated with combined heart and liver transplantation for familial amyloidotic cardiomyopathy.

BACKGROUND: The amyloidogenic transthyretin (ATTR) mutation Leu111Met causes a primarily cardiac amyloidosis: Familial amyloidotic cardiomyopathy (FAC). Combined heart-liver transplantation (CHLTx) is the preferred treatment for patients with heart failure due to familial amyloidosis, but information on outcome of patients with Leu111Met mutation is limited. The aim of this study was to evaluate the long-term outcome of CHLTx in patients with FAC. METHODS AND MATERIALS: Between 1998 and 2009, CHLTx was performed in 7 FAC patients (four men). Six patients underwent simultaneous transplantation. All patients suffered from severe cardiomyopathy. RESULTS: Mean recipient age at transplantation was 48.3 ± 4.2 yr. Mean follow-up was 55 months. No peroperative mortality occured. Two patients died within the first year (infection, multi-organ failure) of transplantation. Cumulative survival at 4.5 yr was 71%. No significant liver rejections occurred. One patient experienced an episode of cardiac rejection requiring treatment (H2R). For the surviving five patients, most recent left ventricular ejection fraction was 0.61 ± 0.02, and plasma creatinine was 129 ± 47 µM. None developed significant allograft vasculopathy or neuropathy after transplantation. No recurrence of cardiac amyloid was found. CONCLUSIONS: CHLTx in selected patients with FAC due to Leu111Met mutation offers acceptable long-term survival, almost comparable with isolated cardiac transplantation. Allograft rejection was rare.

Driveline infections in patients supported with a HeartMate II: incidence, aetiology and outcome.

OBJECTIVES: To investigate the incidence and outcome of driveline infections in patients supported with a continuous flow left ventricular assist device (HeartMate II (HMII)) and to study the microbiological aetiology. DESIGN: Retrospective analysis of 31 patients who received an implantation of a HMII. Follow-up was from implantation to either device explantation, death or closure of the study. Clinical signs of infections were divided into superficial, deep or systemic and compared to culture and gram stain, the clinical course and infectious parameters. RESULTS: The incidence of driveline infections was 1.65 episodes per patient per year. Staphylococcus aureus and Escherichia coli were the most common bacterial aetiology. More than two weeks of treatment was required in 81% of the patients. In terms of detecting superficial driveline infections, leucocyte count demonstrated a sensitivity of 27% and C-reactive protein (CRP) a sensitivity of 28%. In 22 cases of driveline infections plasma pro-calcitonin was found to be normal. CONCLUSION: Driveline infections are common in HMII recipients but primarily remain superficial and are reasonably easy to manage. Infectious agents mostly originate from the skin and gastrointestinal tract. Blood biomarkers did not appear to be helpful in detecting driveline infections.

Impact of fixed pulmonary hypertension on post-heart transplant outcomes in bridge-to-transplant patients.

BACKGROUND: Fixed pulmonary hypertension (FPH) is considered a contraindication to cardiac transplantation. Ventricular assist device (VAD) therapy through prolonged left ventricular unloading may reverse FPH. Our aim was to assess post-transplant outcomes and survival in patients with and without FPH undergoing VAD implantation as bridge to transplant. METHODS: Fifty-four patients received an intracorporeal left VAD (LVAD) as a bridge to transplant from 2000 to 2008 at two institutions (Rigshospitalet, Denmark, and the Toronto General Hospital, Canada). Twenty-two (41%) patients had fixed FPH (defined as pulmonary vascular resistance [PVR] >3 Wood units and resistant to pulmonary vasodilators) prior to VAD implant (FPH group) and were compared with 32 patients without FPH (NoFPH group). Baseline characteristics, pre- and post-transplant pulmonary pressures, incidence of complications and post-transplant survival were analyzed. RESULTS: Baseline characteristics were similar except that patients in the FPH group were older (46 ± 11 years vs 39 ± 13 years in the NoFPH group, p < 0.05). The mean pre-VAD PVR was 4.3 ± 1.7 Wood units in the FPH group and 1.7 ± 0.5 Wood units in the NoFPH group (p < 0.001). Pulmonary pressures were higher in the FPH group immediately prior to VAD implant, but they were comparable immediately pre-transplant and during the first year post-transplant. The incidence of post-transplant RV failure was not significantly different between groups. Post-transplant survival was similar between groups. CONCLUSIONS: VAD therapy successfully decreases pulmonary hypertension, even in patients with "fixed" FPH, allowing candidacy for heart transplantation. Among bridge-to-transplant candidates, the presence of FPH does not reduce post-transplant survival.

European results with a continuous-flow ventricular assist device for advanced heart-failure patients.

OBJECTIVE: The HeartMate II (HM II) LVAD is a small, quiet, continuous-flow, left ventricular assist device (LVAD) for circulatory support in advanced heart-failure patients, with over 2000 implants worldwide. This article reports on the European experience with this device. METHODS: The HM II was implanted in 571 patients at 64 European institutions. In 72% of cases (411 patients), implantation has taken place at least 6 months before the closing date of the study (1 August 2008). Patients (19% female, 70% ischaemic aetiology) were on maximum medical therapy, including inotropic support. Body surface area ranged from 1.30 to 2.50 m(2) and age from 14 to 75 years (mean: 51+/-14 years; n=115, 28% over age 60 years). The intention of support was to provide a bridge to transplantation (73%), destination therapy (21%) and a bridge to recovery (6%). Adverse events were documented in the first 53 patients - for obtaining the Conformité Européenne (CE) Mark (group A) - from a European multicentric study (Strüber et al. [Strüber M, Sander K, Lahpor J, Ahn H, Litzler P-Y, Drakos SG, Musumeci F, Schlensak C, Friedrich I, Gustafsson R, Oertel F, Leprince P. HeartMate II left ventricular assist device; early European experience. Eur J Cardiovasc Surg 2008;34(2):289-94.]: 101 patients) and from a single-centre study (UMCU, The Netherlands: 30 patients). RESULTS: The mean support duration ranged from 0 to 1019 days with a mean of 236+/-214 days (249 patients: >6 months, 119: 1 year, 12: >2 years; total support time: 293 years). The overall survival to transplantation, recovery or ongoing device support at the end of the study was 69% (284) with an early mortality of 17.5% and late mortality of 13.5%. Of the surviving patients, 23% have been transplanted, 4% had their device removed after recovery of the left ventricle and 42% are still ongoing. Adverse events included bleeding (ranging from 42% in group C to 59% in group A), percutaneous lead infections (A: 0.19, B: 0.61 and C: 0.18 events per patient year), pocket infections (A: 0.08, B: 0.07 and C: 0.09 events per patient year), ischaemic stroke (A: 0.06, B: 0.09 and C: 0.04 events per patient year), haemorrhagic stroke (B: 0.07, C: 0.04 events per patient year) and transient ischaemic attacks (TIAs; A: 0.08, B: 0.02 and C: 0.13 events per patient year). CONCLUSIONS: These results support the use of the HM II continuous-flow LVAD for long-term support as a bridge to transplantation and possibly for destination therapy. Future emphasis should focus on minimising adverse events such as infections, bleeding and neurological events.