Michiel Morshuis

Fully Magnetically Levitated Left Ventricular Assist System for Treating Advanced HF: A Multicenter Study

BACKGROUND The HeartMate 3 left ventricular assist system (LVAS) is intended to provide long-term support to patients with advanced heart failure. The centrifugal flow pump is designed for enhanced hemocompatibility by incorporating a magnetically levitated rotor with wide blood-flow paths and an artificial pulse. OBJECTIVES The aim of this single-arm, prospective, multicenter study was to evaluate the performance and safety of this LVAS. METHODS The primary endpoint was 6-month survival compared with INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support)-derived performance goal. Patients were adults with ejection fraction ≤ 25%, cardiac index ≤ 2.2 l/min/m(2) without inotropes or were inotrope-dependent on optimal medical management, or listed for transplant. RESULTS Fifty patients were enrolled at 10 centers. The indications for LVAS support were bridge to transplantation (54%) or destination therapy (46%). At 6 months, 88% of patients continued on support, 4% received transplants, and 8% died. Thirty-day mortality was 2% and 6-month survival 92%, which exceeded the 88% performance goal. Support with the fully magnetically levitated LVAS significantly reduced mortality risk by 66% compared with the Seattle Heart Failure Model-predicted survival of 78% (p = 0.0093). Key adverse events included reoperation for bleeding (14%), driveline infection (10%), gastrointestinal bleeding (8%), and debilitating stroke (modified Rankin Score > 3) (8%). There were no pump exchanges, pump malfunctions, pump thrombosis, or hemolysis events. New York Heart Association classification, 6-min walk test, and quality-of-life scores showed progressive and sustained improvement. CONCLUSIONS The results show that the fully magnetically levitated centrifugal-flow chronic LVAS is safe, with high 30-day and 6-month survival rates, a favorable adverse event profile, and improved quality of life and functional status. (HeartMate 3™ CE Mark Clinical Investigation Plan [HM3 CE Mark]; NCT02170363).

European experience of DuraHeart™ magnetically levitated centrifugal left ventricular assist system

OBJECTIVE The DuraHeart (Terumo Heart, Inc., Ann Arbor, Michigan, USA) is the worlds first approved magnetically levitated centrifugal left ventricular assist system designed for long-term circulatory support. We report the clinical outcomes of 68 patients implanted with the DuraHeart as a bridge to cardiac transplantation in Europe. METHODS Sixty-eight patients with advanced heart failure (six females), who were eligible for cardiac transplantation were implanted with the DuraHeart between January 2004 and July 2008. Median age was 58 (range: 29-74) years with 31% over 65 years. Thirty-three of these patients received the device as a part of the European multi-center clinical trial. Survival analyses were conducted for 68 patients and other safety and performance data were analyzed based on 33 trial patients. RESULTS Mean support duration was 242+/-243 days (range: 19-1148, median: 161) with a cumulative duration of 45 years. Thirty-five patients (51%) remain ongoing, 18 transplanted, 1 explanted, and 14 died during support with a median time to death of 62 days. The Kaplan-Meier survival rate during support was 81% at 6 months and 77% at 1 year. Of the 13 patients (21%) supported for >1 year, 4 supported for >2 years, 1 supported >3 years, 2 transplanted, 2 died, and 9 ongoing with a mean duration of 744+/-216 days (range: 537-1148, median: 651). Major adverse events included driveline/pocket infection, stroke, bleeding, and right heart failure. There was no incidence of pump mechanical failure, pump thrombosis, or hemolysis. CONCLUSIONS The DuraHeart was able to provide safe and reliable long-term circulatory support with an improved survival and an acceptable adverse event rate in advanced heart failure patients who were eligible for transplantation.

Single-center experience with the thoratec ventricular assist device☆☆☆

OBJECTIVE The Thoratec ventricular assist device (Thoratec Laboratories, Pleasanton, Calif) is widely accepted for univentricular and biventricular support in patients with various indications. The aim of this study is to describe our experience with implantation of the Thoratec ventricular assist device in more than 100 patients. METHODS From March 1992 to June 1998, 114 patients (98 men and 16 women; mean age, 47.9 years) received the Thoratec ventricular assist device for a mean duration of 44.9 days. The patients were divided into 3 groups. Group 1 included 84 patients in whom the system was applied as a bridge-to-transplant procedure. Group 2 included 17 patients with postcardiotomy cardiogenic shock, and group 3 included 13 patients with cardiogenic shock of other causes. RESULTS Sixty-eight percent of patients in group 1 survived to transplantation with a posttransplant survival of 88%. The only independent risk factor affecting survival was age more than 60 years. Survivals in groups 2 and 3 were 47% and 31%, respectively. Main complications in all groups were bleeding, multiple organ failure, liver failure, sepsis, and neurologic disorders. CONCLUSIONS The Thoratec ventricular assist device has proved to be a reliable device for bridge to transplantation and postcardiotomy support. Further studies are required on patient selection and on patient and device management to reduce the incidence of complications in these patient populations.

Preliminary experience with the lionheart left ventricular assist device in patients with end-stage heart failure

BACKGROUND The Arrow LionHeart LVD 2000 left ventricular assist device is the first fully implantable system designed for destination therapy. We report on 2 years of experience with this device, which we implanted for the first time in October 1999. METHODS Since October 1999, 6 male patients between 55 and 69 years of age (mean 65 +/- 6 years) have received the device at our center; all were in New York Heart Association functional class IV and ineligible for heart transplantation. RESULTS All surgical procedures were uneventful, with a timely extubation in 5 of 6 patients. Duration of support was 17 to 670 (mean 245 +/- 138) days, with a cumulative experience of 4.5 years. Three patients recovered to be discharged from hospital under support and are long-term survivors. Three patients died 17, 31, and 112 days after implantation from multiple organ failure without being discharged to their homes. The survival rate is 50% after 18 months. There were no major system-related problems or any device-related infections, which are otherwise commonly found among vertricular assist device patients. CONCLUSIONS Our preliminary experience demonstrates the reliability and efficacy of the different parts of the system. Nevertheless, further sophistication is needed to reduce the size of its components, which so far still constitutes a limiting factor.

Results with SynCardia total artificial heart beyond 1 year.

Mechanical circulatory support devices have been increasingly used for long-term support. We reviewed outcomes in all patients supported with a SynCardia total artificial heart (TAH) for more than 1 year to assess its safety in long-term support. As of December 2011, all 47 patients who received the TAH from 10 centers worldwide were included in this retrospective study. Clinical data were collected on survival, infections, thromboembolic and hemorrhagic events, device failures, and antithrombotic therapy. The mean age of patients was 50 ± 1.57 years, the median support time was 554 days (range 365–1373 days). The primary diagnosis was dilated cardiomiopathy in 23 patients, ischemic in 15, and “other” in 9. After a minimum of 1 year of support, 34 patients (72%) were successfully transplanted, 12 patients (24%) died while on device support, and 1 patient (2%) is still supported. Five patients (10%) had a device failure reported. Major complications were as follows: systemic infections in 25 patients (53%), driveline infections in 13 patients (27%), thromboembolic events in 9 patients (19%), and hemorrhagic events in 7 patients (14%). SynCardia TAH has proven to be a reliable and effective device in replacing the entire heart. In patients who reached a minimum of 1 year of support, device failure rate is acceptable and only in two cases was the leading cause of death. Infections and hemorrhagic events were the major causes of death. Patients who remain supported beyond 1 year are still likely to survive to transplantation.

DuraHeart™ magnetically levitated centrifugal left ventricular assist system for advanced heart failure patients

The implantable left ventricular assist system (LVAS) using pulsatile pump technology has become an established therapeutic option for advanced heart failure patients. However, there have been technological limitations in some older designs, including a high incidence of infection and mechanical failures associated with moving parts, and the large size of both implantable pump and percutaneous cable. A smaller rotary blood pump emerged as a possible alternative to a large pulsatile pump to overcome some of these limitations. The technological advancement that defines the third-generation LVAS was the elimination of all mechanical contacts between the impeller and the drive mechanism. The DuraHeart™ LVAS is the world’s first third-generation implantable LVAS to obtain market approval (CE-mark), which combines a centrifugal pump and active magnetic levitation. The initial clinical experience with the DuraHeart LVAS in Europe demonstrated that it provided significantly improved survival (85% at 6 months and 79% at 1 year), reduced adverse event rates and long-term device reliability (freedom from device replacement at 2 years: 96 ± 3%) over pulsatile LVAS.

Global gene expression analysis in nonfailing and failing myocardium pre- and postpulsatile and nonpulsatile ventricular assist device support

Mechanical unloading by ventricular assist devices (VAD) leads to significant gene expression changes often summarized as reverse remodeling. However, little is known on individual transcriptome changes during VAD support and its relationship to nonfailing hearts (NF). In addition no data are available for the transcriptome regulation during nonpulsatile VAD support. Therefore we analyzed the gene expression patterns of 30 paired samples from VAD-supported (including 8 nonpulsatile VADs) and 8 nonfailing control hearts (NF) using the first total human genome array available. Transmural myocardial samples were collected for RNA isolation. RNA was isolated by commercial methods and processed according to chip-manufacturer recommendations. cRNA were hybridized on Affymetrix HG-U133 Plus 2.0 arrays, providing coverage of the whole human genome Array. Data were analyzed using Microarray Analysis Suite 5.0 (Affymetrix) and clustered by Expressionist software (Genedata). We found 352 transcripts were differentially regulated between samples from VAD implantation and NF, whereas 510 were significantly regulated between VAD transplantation and NF (paired t-test P < 0.001, fold change >or=1.6). Remarkably, only a minor fraction of 111 transcripts was regulated in heart failure (HF) and during VAD support. Unsupervised hierarchical clustering of paired VAD and NF samples revealed separation of HF and NF samples; however, individual differentiation of VAD implantation and VAD transplantation was not accomplished. Clustering of pulsatile and nonpulsatile VAD did not lead to robust separation of gene expression patterns. During VAD support myocardial gene expression changes do not indicate reversal of the HF phenotype but reveal a distinct HF-related pattern. Transcriptome analysis of pulsatile and nonpulsatile VAD-supported hearts did not provide evidence for a pump mode-specific transcriptome pattern.

Mechanical circulatory support devices as destination therapy-current evidence.

Advanced heart failure is an increasing problem worldwide. Nowadays, mechanical circulatory support devices (MSCD) are an established therapeutic option for terminal heart failure after exhaustion of medical and conventional surgical treatment, and are becoming a realistic alternative to heart transplantation (HTX). There are a number of different treatment options for these patients, such as bridge to transplantation (BTT), bridge to candidacy (BTC), bridge to recovery (BTR) and the destination therapy (DT) option. The latter option has become more frequent throughout the last years, due to a donor organ shortage and an increasing number of older patients with terminal heart failure who are not eligible for HTX. These factors have led to a rapidly increasing number of LVAD implantations as well as centers which perform these procedures. This has also been due to improved LVAD survival rates and quality of life following the introduction of smaller, intrapericardial and more durable continuous flow left ventricular devices. The most common complications for these patients are device-related problems, such as coagulation disorders, gastrointestinal bleeding, device related infection, pump thrombosis or cerebrovascular accidents. However, some questions still remain unanswered or under debate, such as the exact time-point for LVAD implantation. In addition, aspects such as better biocompatibility for LVADs remain a major challenge. This review will concentrate on DT for terminal heart failure and provide an overview of the current evidence for LVAD implantation in this patient group, with particular emphasis on indication and time-point of implantation, choice of LVADs, and long term outcomes and quality of life.

The biomarker plasma galectin-3 in advanced heart failure and survival with mechanical circulatory support devices.

BACKGROUND During screening of heart transplantation (HTx) candidates supported by ventricular assist devices (VADs) for plasma biomarkers we found that galectin-3 (Gal-3) was increased pre-operatively in patients who later died during VAD support. Therefore, we analyzed the predictive value of plasma Gal-3 in the context of other potential clinical risk factors for death on device (DOD) in a cohort of 175 VAD patients. METHODS We analyzed numerous clinical factors and plasma Gal-3 levels of 175 VAD patients before device implantation. Eighty VAD patients were successfully bridged to HTx (BTT, 45.7%), 80 (45.7%) died on VAD, 2 recovered on device (BTR, 1.1%) and 13 (7.4%) were still on device. Uni- and multivariate analyses were performed to assess the importance of Gal-3 with respect to other clinical factors. Myocardial gene expression of Gal-3 was investigated in apex samples by RT-PCR (n = 30) and Western blotting (n = 45). RESULTS Plasma Gal-3 levels were higher in VAD patients than in controls (16.6 ± 9.3 vs 9.5 ± 3.9 ng/ml, p < 0.0001). Cox regression showed several clinical factors and type of VAD as independent outcome predictors, but Gal-3 was not among them. Using the regression equation we grouped patients according to their factor constellation for prediction of survival on VAD. We propose a calculation method for VAD survival prediction. Gal-3 mRNA and protein were detectable in failing myocardium, but did not correlate with its plasma concentration. CONCLUSIONS Galectin-3 levels are associated with severe heart failure but do not provide sufficient discrimination for prediction of outcomes after VAD implantation. Importantly, we were unable to confirm myocardial tissue as a primary source for the observed plasma elevations of Gal-3.

Localizing an occult gastrointestinal bleeding by wireless PillCam SB capsule videoendoscopy in a patient with the HeartMate II left ventricular assist device.

Gastrointestinal bleeding is a known problem in patients with left ventricular assist devices (LVADs). The exact source of the bleeding is sometimes difficult to ascertain. In gastroenterology, wireless capsule videoendoscopy has become an important diagnostic tool, especially when the small intestine is involved. It is not known, however, whether an implanted LVAD would interfere with signal transmission from the capsule, nor whether the signals from the capsule would cause malfunction of the LVAD. We report the case of a patient in whom significant gastrointestinal bleeding developed after implantation of a HeartMate II LVAD (Thoratec Corporation, Pleasanton, Calif). The source of the bleeding was successfully identified by wireless PillCam SB capsule videoendoscopy (Given Imaging Ltd, Yoqneam, Israel).